Had a crazy thought. Wondering if it is possible to use a python script to set the focus setting in the P5 render option by keying it to the location of a ball prop in your scene. By this I mean, where I place the ball prop being sort of the crosshairs to determine focus depth, etc. So, is that a pipe dream or is it doable? [bows deepy and reverently as he backs away from the altar]

Do you mean these settings? If these show up in a PZ3, it should be possible. Python would pick up the ball's location, write the corresponding focus data into a "dummy" PZ2, and quietly import the PZ2. You'll have to specify what relationship you want in numerical form, because I know nothing from focus!

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Yes, that's the settings I'm referring to. That info appears to save in the pz3 as the settings stay as set whenever I reload the pz3 file. We might need help from someone who understands the focus data better, my photography skills are a bit rusty. So far I have been doing trial and render - and that ain't working out too hot! [bows worshipfully again]

Er, is there a Doctor in the house???

Here's a trial version, with a totally arbitrary relationship. The Ball Z is taken as the focal length, and Ball Y * 2 is taken as the f-stop. See if this gives you a more empirical sense of how the relationship should really work..... Edit: in case it's not obvious, you move the ball, make sure the ball is still selected, then hit the script.

Message edited on: 11/21/2004 15:13

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Wow! you are fast! I will give this a try now and let you know how it does. Thanks a bunch [grovels in obeisance]

I think the length should really be based on crow-flies distance from current camera, but this will at least give your hand-eye coordination some exercise until we hear from somebody who knows cameras.

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gapes You, Ockham, are a brilliant, brilliant human being. I'm not big on religion, but when you meet someone who can work miracles at will, it certainly makes you think about moving to California and starting a cult! ~To you, Ockham, LORD OF SCRIPTS, we give these blessings ~Calloo Callay, Calloo Callay, in your name we rejoice! So, um, anyway, is there somewhere we can go to bribe, er, um, donate to you? :)

I'll experiment with the script tonight and see if I can get a good handle on the relationship between real life photography and Poser-ese, btw. ;) (I'd do it now, but I'm leaving in twenty minutes, so I won't have the chance... I can't work as quickly as you. :P )

Even approximate at this point is probably going to yield better results than what I have gotten thus far just playing with fstop and focal depth settings. Now, so as to not be too big an igit when I do this, let me make sure I am clear on what I am doing. I am loading two ball props - or just one? into my scene. I position these (er with one I would put it on the figure I want in focus - not sure about the other) Then I apply the python, render and do the happy snoopy Is that about it?

Just one ball. The Z-distance from center becomes the focal distance, so the idea is that you put the ball on the location where you want the focus. (As I mentioned, this won't be numerically right; it really should be dist from current camera.) The height (Y tran) becomes the F-stop, which may not feel right. Maybe more intuitive if the scale controls the F-stop?

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" I think the length should really be based on crow-flies distance from current camera," Correct. Here's how to calculate the focal length to get the currently selected object in focus (in PNU):

import poser, math

scene = poser.Scene()
actor = scene.CurrentActor()
cam = scene.CurrentCamera()

p1 = actor.WorldDisplacement()
p2 = cam.LocalDisplacement()
p3 = actor.Origin()
d = (-p3[0] + p2[0]-p1[0], -p3[1] + p2[1]-p1[1], -p3[2] + p2[2]-p1[2])
mag = math.sqrt (d[0]*d[0] + d[1]*d[1] + d[2]*d[2])

Btw, here is a good reference to give you an idea what the relationship is, shadownet and Ockham:

http://www.mir.com.my/rb/photography/fototech/htmls/depth.html (The link includes both technical and layman's explanations)

Message edited on: 11/21/2004 15:50

Bookmarking this thread : I'm really in need of something understandable to set the focus in my pics.

Is the var you've labeled as 'mag' the same thing as focal length? Or does it need another formula?

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The focal distance should be the distance between the prop and the camera. At this distance will be the maximum sharpness (point of focus). Stewer has a script to calcualte it from the position of a prop. The f-stop, together with the camera focal length, controls how deep the sharp area will be. If poser accuratly models a real lens, this area will be deeper behind the point of focus than in front of it. A bigger F-stop number gives a bigger sharp area.

Oops; crossposted with stewer!

So could it be possible to have one ball to be positioned on the point of focus, then its scale expanded or reduced to get the boundaries of the "sharp zone" ? (sorry if it doesn't make sense : I know nothing about real life cameras).

So could it be possible to have one ball to be positioned on the point of focus, then its scale expanded or reduced to get the boundaries of the "sharp zone" ? In pmath terms, you would want the target object's scale to be directly or indirectly proportional to f-stop?

'mag' is the final value in PNU - I just named the value like that because it's the magnitude of the vector between the object and the camera.

sorry. 'indirectly' should be 'inversely' in my above statement. (running late, excited about topic... arggh)

thanks for the link softriver, definitely will be useful. And a lot easier than rummaging through the storage boxes trying to find my old photography books. Stewer - okay you qualify as a GOD too. Scratches head and leaves it up to Ockham to understand godspeak. :O)

Thanks, Stewer. So here's another version, using your mag * 8 as the focal length in feet, and using the ball's scale to control f-stop. Is there a linear relationship between the f-stop number and the area or diameter of the "sharp region"?

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Edit: Is there a numerical relationship (linear or otherwise) between the f-stop number and the area or diameter of the "sharp region"?

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okay, too many grey cells at work here, I'm going to sit back and look on worshipfully

Is there a numerical relationship (linear or otherwise) between the f-stop number and the area or diameter of the "sharp region"? Not one I can specify. I believe it's an inverse square. Here's the general data (re-posted from link): The smaller the aperture, the deeper the depth of field (the other two factors remaining the same). For example, if the lens focal length and the shooting distance stay the same, the depth of field is much deeper at f/16 than at f/1.4.

I don't want to miss this.

I don't want to miss this.

Yes. Rare opportunity to see dorks in their native habitat, eh? 8D

grins dorkily while calling to tell her parents she'll be late for dinner EDIT: Please don't think I'm calling anyone else a dork, but I relish my dork-dom. It is a badge of pride! =P Message edited on: 11/21/2004 16:32

I B A Dork too! (he says with swelled chest) :O)

bookmark.

Dork? I thought it was Nerd! That's what I used to call them. Well, till I became one too! LOL.

Another quick question to Ockham... Does it matter, what I've selected in general preferences? Poser Units, centimetres, feet... ? Or will the script work with any of the possible settings properly?

Yesterday's the past, tomorrow's the future, but today is a gift. That's why it's called the present.

Nerd is the right word, dork is a certain body part. ;)

Hmm, tried the script on the pic I am currently working on but the spot where I put the ball is not seeming to be the focal point. This may be cause I have my camera rotated in my universe. I will set up a new scene with some props and see if I can get a better handle on how the ball placement works.

Can I just say before I leave that this script is a brilliant idea. Translating a skill that in real life often equates to "fiddling with your camera" (for people who aren't professional photographers) into Poser is long overdue. THANK YOU OCKHAM!

Attached Link: http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/950/depth-of-field.html

@Ockham An f-stop is a measure of how wide the aperture of a camera lens is. It is intimately tied up with 2 things; the amount of light that is let into the camera (not really relevant here) and the depth of field (which is). DOF is about how far before and beyond a plane (the focal plane) other objects remain in focus. The above link helps explain depth of field. Just what the exact mathematical relationship is I'm not sure, but I don't think it involves the inverse square rule (at least, not in simple cases:-) but it certainly involves some trig:-))

Hope it helps (result of simple google for "depth of field")

Cheers,
Diolma

Message edited on: 11/21/2004 17:09

Attached Link: http://www.keindesign.de/stefan/poser/index.html

Not really talented enough to be considered for the dork hall of fame. A follower really. Didn't Stefen of http://www.keindesign.de/stefan/poser/index.html make a script to set Depth of Field and Focal distances some time ago? I read such in another thread and downloaded his script some time ago. I had saved the URL in my Faves. Hope this is on topic ...

Does it matter, what I've selected in general preferences? Poser Units, centimetres, feet... ? No, it doesn't matter. The internal values (which Python sees) are always in PU.

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So it sounds like there isn't really a numerically definable relationship between aperture and "sharp region"? I've been Googling some of that stuff, and I'm frankly lost. Seems to be considerable argument among the various tutorials, with some debunking the others!

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Nothing like reinventing the wheel or building a better mousetrap. :O) Cool link Rance01 looke like a lot of useful info for folks new and ignorant to P5 - of which I B #1

The way I heerd it, a nerd is one who has no social skills and knows it. A dork is one who has no social skills and doesn't know it. (I've run into a lot of salesmen in computer stores who are purebred dorks, for some reason.)

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LOL @ Ockham!!! BTW - it's not limited to computer stores.... Cheers, Diolma

I couldn't resist.

Ockham, the script Rance1 mentions looks like what stewer posted and is used to calculate the distance between the camer and objects in focus or Focal Distance option. Maybe you can take a look at the method outlined by Stephen (on his website tutorial on this, which also has the py script) and see if that helps. I like the idea of being able to either pick a figure or place a ball prop where I want my focal point to be and the script do the calculation to give me the depth of field effect I want. So don't give up on this just yet. :O)

Dorks, nerds, or gods, I think you are ALL wonderful. I love these threads ... Rance

There has to be a formula, I have seen tables on deep of field for real camaras. For a given focal length, focal distance, f-stop and film format, the deep of field is the same for every lens. It has to be a optical formula. Unfortunaly I can not find the actual formular in any of my photography books. :-( Anybody with an optics textbook around? I assume Poser simulates a 36 mm film format.

Shadownet, I wasn't all together sure if that's the tool you were thinking about or not. I've a number of Ockham's scripts and know that he's one of the Poser GREATS. I bow low and slowly walk to the next thread. Rance

Rance, I was not familar with that script so thanks. It is useful. I am hoping the great Ockman whose name must be held in awe can do it one better. :O)

Saved the thread to faves. Along with Shading Rates I think Focal Points and Depth of Field are some of the most interesting features of FireFly. Thanks for kicking this thread off. Rance

http://www.schneideroptics.com/info/depth_of_field_tables/ This is for cameras, not sure if it works the same for poser. I haven't tried, but I think to use these you'd have to change the measurement in poser to feet and the focal to the appropriate mm. If python doesn't see anything but PU, then I guess a conversion would be in order. Is that possible with any accuracy? There is an equation, but that's in the realm of physics and I swore off that after college.:) This definitely a thread to watch.

This was just a quickie experiment. It is just my $ .02 for anyone that might be interested in a starting point of reference. I shall try to do a more definative tut on FireFly sometime in the future ... the Good LORD willing and the crick (if you're not from PA, that's creek) don't rise ... too high. ;=] Right now, I've got to worry about some idiot who has installed electronic surveillance equipment right across the street from my new secret (Oops! - I guess it's not secret anymore) laboratory where I do all my Poser experiments. cheers, dr geep ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Where is the secret lab, you say? It's RIGHT HERE. cheers, dr geep ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Now that's the kind of experiment we need here. I strongly suspect that Poser's "camera" has its own set of formulae, which bear a only a vague resemblance to the formulae (or tables) for actual film cameras.

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Yup, I 'spect you've hit the ol' nail right on the ol' snozolla. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Attached Link: http://homepage.mac.com/leemoon/DOF-HelperPoser5.pdf

Not sure if this will help or not... This is what I do to generate my DOF renders. What it doesn't do is show you the DOF range. It only shows the focal plane (which is still extremely helpful.) Anyway, go to the address in this message and download the PDF file showing what I'm doing. Perhaps someone can come up with some other visual markers showing the close and far DOF range.

Here's the PDF address:
http://homepage.mac.com/leemoon/DOF-HelperPoser5.pdf

Hope this is of benefit. :)
Lee

.

Wow! I think I died and have gone to Poser heaven. This is some great stuff folks. Thanks for the pdf LeeMoon, and Geep, its good to know the DR. still makes house calls. Now about that electronic surveilence equipment, what you want to do - voice fades to a whisper....put on some Pink Floyd, the Wall is a good choice, and point the speakers that way. Better than white noise any day. :O)

Hmmm ............... vedddddy interesting ! ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Oh, and about that hou$e call ........ you'll get my bill. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

That's good, and you will get mine for TSCM (er in layman's terms technical surveilence countermeasures, ie. debugging what bugs yah) :O) Strangely enough they should cancel each other out - what is commonly known in the TSCM field as nullification. I'd tell yah more but then...well you know the rest. ;O) On a more serious note, looking forward to seeing what else you can come up with on DOF. So far I am spinning my wheels and not making much headway on my tests. But that's why I am only Eeegor and you are the Doc.

Would you be willing to help me with an experiment? My thought is this: We can set up a poser cube at the origin, which would be the focus object, then set up additional cubes every 1 poser unit aligned to the axes of the ground plane (x and z). Then, by modifying the f-stop in prearranged steps, we can get a rough estimate of the "sharpness zone" in poser units. If we arranged that data into a tabular format, it shouldn't be too hard to use a spreadsheet to graph the information and come up with a "close enough" mathematical formula to describe the curve. In order to check our results, we could try the experiment several ways. My suggestion is that we would: a. Get the data for 10 separate f-stop values at 35 mm with a set distance frm the focal point. b. Get the data for the same f-stops at 70 mm with the same distance from the focal point. c. 10 renders, same f-stop values, 35 mm, double the distance from focus. d. 10 renders, same f-stop values, 70 mm, 2x distance from focus. That would require 40 renders in all, which could give us a reasonable data set to generate some real relational data. Can anyone think of a reason this wouldn't work? I can probably set the experiment up as a pz3, and host it on my server, so that anyone with a decent connection speed could contribute or try variations I haven't thought of.

Notes: the reason I suggest a cube is that we can get a good guess at the "sharpness falloff" based on the distortion of the visible edges, which we could reasonably agree to be the standard for measurement. ( If the cube on 0, 8 is fuzzy around the edges, then the sharpness measurement would be expressed as 8 pu's from focus to edge )

I think it a good idea. I was also going to suggest someone set up a pz3 and everyone use it to have a controlled test. Since you also thought of that all I can do is applaud you for your efforts and volunteer to help do the test renders. I think if we can furnish ockham with the right data he can make a script that will simplify using DOF in P5.

Oh, and I would make the instructions as to the how to steps to perform the test as "dummy free" as possible since I tend to confuse easy until things sink into my thick noggin. :O)

Setting up the pz3 now. :) I'll post when it's available.

Well, I have the basic PZ3 set-up, but there is a problem. (Actually a few)

First of all, the script is insistng on calling a figure (or possibly a prop that is attached to a figure). So, it won't set my Focal Distance against the ball prop.

I might be able to get around that by loading the DNA_Skydome, but that brings me too my next problem:

1. If I add a figure to the scene I can't redistribute the pz3. (I can use HER, but I won't without sixus1's permission - even if it is a free figure ... Same with the DNA Skydome)

2. If I add a figure, the pz3 will bloat pretty badly, making it a much larger download. That's not a problem on my end. I have more bandwidth and storage than I know what to do with, but it will make things a lot more difficult to download.

If I don't load a figure, then the focal distance and f-stop defaults are too messed up for me to get a clue as to what are reasonable settings to focus on the box. :(

I've not gotten a reasonable focus on the box after several tries (actually, several millions of tries)

stewer, if I'm reading your code correctly, the value I'm trying to establish (focal distance) should be determinable by calculating the resultant vector from the vectors formed from the difference in position between my camera and my focus on the x, y, and z axes?

If that's the case, then there has to be some offset value between the camera and the prop, or some variable I'm not seeing, because I don't think I'm screwing up the math. :(

Hm....digging deeply in my first Poser experiences, it may actually be that there is some extra offset to the main camera that my script is ignoring. Will need to do some research. As for having a figure - just load the ball prop, enter the setup room, leave the setup room. There's your redistributable figure :)

Good call, stewer. Thanks! looks around to make sure no one's going to get upset for us redistributing a primitive =D (It's really cool to know I was right about the math function you were describing, btw. Think I should write a note to my Physics professor to let him know that the only use I've had for his semester of hard work was a failed attempt to calculate the distance between a virtual camera and an imaginary ball? 8D )

Ok. I got the script to work, but the focal length it returns doesn't appear to be right. (It returns a value of 24.802 for focal distance, which, after 8 or 9 test renders at varying f-stops seems to put my focus well beyond the figure. :( I'll zip up the pz3 real quick so that you can check it if you want (or so that others can download it and experiment).

Scratch that... It's good now. give me a few minutes before I post the pz3. (the focal length is right, it's me that's wrong in this case) ;)

Ok. Here's the link to the .pz3:

http://www.studioverite.com/forums/freebies/focalexperiment.zip

The boxes are spaced .2 pnu apart. The white box in the center is the focus, with teach box alternating color.

Ockham and stewer's script returned a focal distance of 24.802 which seems right.

I set the render size up at 1200x1200 so that there'd be enough detail to see a noticeable change.

I figured that starting with an f-stop of 10.0 we can work our way down to 1.0 in whole steps. Try to make a best judgement on where the distortion starts and ends on both the horizontal boxes and the vertical boxes. The distortion should increase as the f-stop value decreases.

I'm going to warn everyone in advance that rendering those 21 boxes under full production mode (which is set up by default on the .pz3) may require some firepower. It's not too bad at an f-stop 10, but at 1 my machine was crawling.

The pz3 is only a 10k compressed, so everyone should be able to get it pretty easily, even on dial-up. :)

Enjoy! Note: I'm not sure if this experiment is valid or not. In order to get a mathematical idea of what's happening we might need to look at the amplitude of the effect instead of the area of the effect, which will be much harder to come up with empyrical values for. But I'm not going to write it off completely til I've run it a few different ways.

And btw, even if it doesn't work out, we can just give the ball linear control over f-stop and still have more information on how to use it effectively. =D

BOOKMARK

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Is there any way to automate the script to recalculate and alter the DOF settings between frames on an animation? I'm not sure how deep the Python rabbit hole goes. I assume that Poser ignores scripts while rendering an animation sequence (?), but animated DOF would be suh-weet! So I figured I'd ask, just in case. =D

...gotta go to work...just stumbled on this...must come back...

looks around to make sure no one's going to get upset for us redistributing a primitive Nothing is being redistributed. Look inside the pz3, the sphere geometry is only referenced.

Great stuff.

About animating this - that'd be tough. By default, the depth of field parameter is not animateable. You could maybe do it with a python script that: 1. writes a partial pose file containing render settings with focal length (see ockham's script above) 2. renders the current frame, saves it 3. advances one frame 4. repeat until animation is finished

Got the test file. Must do a little work this morning. Will play, er experiment, later today. Thanks for setting thing up Softriver. Hope my little ol puter is up to the challenge. :O) Stewer thanks a bunch for your imput also. P.S. If I am sounding a bit MommaHennish it's cause I started the thread, and I feel "thanks you" are in order for everyone taking part. To me, this is the forum at its best. Not just moaning and groaning but finding ways to make Poser better - yeah just like in them good old days :O)

Yeah !!!

But, .............. just think ...

... at some time in the future ...

... These days will be ...

............................................... "them 'good old days.' "

Think about it. ;=]

cheers,
dr geep
;=]

( It's ok, shadownet, ... I miss 'em, too.)

Message edited on: 11/22/2004 09:47 ..... to remove all TOZ violations ... ;=]

Message edited on: 11/22/2004 09:48 ... to add the "to remove all TOZ violations" statement.

Message edited on: 11/22/2004 09:50 ... to add the "to add the "to remove all ... ... Oh ... nevermind. ;=[

Message edited on: 11/22/2004 09:53

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

The above post was brought to you by: Editor's Anonymous ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

he he, that Anonymous guy sure gets around

He gots lots 'n lotsa brothers. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Bookmark It's very interesting...

Yes, animating this would be coolest for sure - like the camera guy turning the focus ring slowly and switching focus from BG to FG, film style. Yummy.... :] Fish

Yes, it would be cool if the fstop setting can be animated. It would also make this test faster/easier as we could do a batch render frame 1-10 with fstop 1-10, etc. Remember Necessity is not the true Mother of Invention - laziness is. :O)

... and NSG is the father of "laziness." As a matter of fact, he invented it. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Ask NSG if he happens to be his father's son's mother's offspring on his daddy's side?

Don't hold your breath, ... ... it will probably take him at least, um, er, oh, about, um, er, ....... 5 years just to diagram that question ... so he can figure out what you "axed" him. BTW - He's "stoopid," also. But, you can learn more about that in Tutsin Comix, Issue #2. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Besides, NSG's father died tragically when he drowned in a small pond about 2 years before NSG was born so, he never met his father. His mother disavowed any knowledge of ... She used to watch alot of "Mission Implausable" on the TV. I think there might be a connection there. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

DRAT! I always thought that was "Mission Implosable" (after watching those episodes where the plot collapsed in on itself). Thx for clearing that up for me..:-)) Cheers, Diolma

If anyone who has downloaded the test has managed to get through a series of the renders, please e-mail your results to me as a text file at softriver@studioverite.com)

So far, I've gotten through all four stages of the test with mixed results (I'll post them after I hear back from a few people).

Ockham, I was thinking about how to make this idea more intuitive. Instead of the target figure's scale, would it be possible to use (f-stop value = x rotation(in degrees)/10)? That would give us a value of 0 to 36.0 for f-stop (disregarding Poser's 6 sig digits) and we'd be able to "fiddle" the value with a linear dial twist.

I've come up with a few problems involved with the "scaled f-stop" idea. Mainly, getting a high f-stop value might require creating scene occlusion. Rotating the sphere in x, however seems more natural. stewer: Does Poser actually use -180 to 180 degree references? If so, linking to rotational value would mean including a line that flopped negative rot values to a positive integer, right? If that's necessary, I can post C++ code to do so, and you Python gods can just convert it if you like. =D

Just logged on and stopped by this thread to see how things are going. I can't believe how much you've all done. Pretty cool to see everyone with their sleeves rolled up. Glad I bookmarked ...

Hi softriver, taking me a while to render. I have the first 10 done. Starting on the next 10 soon. Also will be gone tomorrow so not sure I will get this wrapped up until Wed. Will try though. :O) Geep - tell NSG that's okay, cause he's stoopid and he knows he's stoopid. That puts him one up on a lot of other folks. :O) P.S. On the subject of his partenage - so that's what you've been doing in your secret laboratory. Let me guess, EEgor mixed up the bottles with the brains again. :O)

shadownet, You're close ................... REAL close. ;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

I'm in the weeds here. Hey, what about using a ruler object running along the z-axis setting near the sphere or focus object. Wouldn't that blur outside of the focal area? One of the pages in the above link used a tape measure looking thing ... And what's the deal with Poser Units and English Feet and/or inches. I did a search and found a thread featuring our good Dr. Is one Poser Unit 8'?!!! I'll be here in the weeds ... Rance

he he Softriver - what camera settings are you using for the other 3 tests? I realize when I change the main camera to 70mm that I will need to adjust the DollyZ to see all the boxes. So will this through things off if we all do it differntly? If we wanting a controlled test, should we not all be using the same settings? Or does it matter? Just checking. Will not pretend to really understand what I am doing. Just rendering. LOL

Xpost - the he he was for Geep :O)

re: "And what's the deal with Poser Units and English Feet and/or inches. I did a search and found a thread featuring our good Dr. Is one Poser Unit 8'?!!!"

Uh oh, here we go ................. again.

I'm not gonna touch that one with a 10 Pnu pole.

Anyone ... anyone?

cheers,
dr geep
;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

Sorry, Good Dr., I read further and further, and further. Shadownet, I found a post dated 2002, with you asking for someone to write a python script for calculate focal distance. http://www.renderosity.com/messages.ez?Form.ShowMessage=876578 I DO NOT WISH TO STIR UP THE POSER UNIT TO SCALE ISSUE here. I love and respect our good Dr. and have read a number of his tuts. Please forgive me for the earlier question. Mayhapp I should have stayed in the weeds! I usually don't post much here. I am more of a lurker as I lack the great skills of my betters. Thanks to all working on this project, Rance

Shadownet: For the 70mm tests (1st set) I kept the dolly - z as is. You can't see all of the boxes during those renders, unfortunately, but you'll still be able to see the results for the most part. The other option (which I also used) is to increase the aspect ratio of your render window. I went with 1200 px wide by 1600 px tall. When you double the dolly z, all boxes will be in clear view for both rendersets. Rance- I don't have a ruler object, and Poser's grids don't render for me. Maybe I'm missing something. Also, I want separate objects with no real textures applied to make the renders run as quickly as possible. You should realize that with the DOF settings on a very large render, my box is crawling already with 126 polys, three lights, and no textures (and it's a pretty 'notch pile of silicon). ;) Cheers, soft

I had completely forgotten about that. That must be back when I first got Poser 5, all happy and excited. Then I got really frustrated with it crashing on me and shelved it for about two years. Things have improved since then and I am now happy and excited again to be learning P5. :O)

Softriver, okay I just wanted to be on the same page is all since I was pretty sure moving the camera would change the render results from one person to another if we all did it differently. I will render 70mm with the dolly z as is. I do not understand the other two test. Please explain those. No point my doing the test wrong just cause I'm to thick to figure it out, and to dumb to ask - so I am asking. :O)

re: "I DO NOT WISH TO STIR UP THE POSER UNIT TO SCALE ISSUE here."

Nor do I, my good friend, nor do I ... but, fear not, for the good Doctor knows how to let a sleeping dog lie. ;=]

I was just having a bit of fun with you, ......... sorry 'bout that.

---

My dearest Rance01,

I would forgive you but ... there is no need. ;=]

You raised a perfectly valid point ........ and my simple response is:

If you use "Poser native units" (Pnu's) ...
which are the same as "Wavefront Object (.obj) units
... which are, also, the same between and betwixt Poser4 and Poser5 ... then there is neither a question of calibration nor conversion to anything else.

[caution - rant condition alpha is ON]

I use Dr Geep's Scale (DGS) because ... it works ... it is as simple as that, .............. period.... ;=]

Others may choose to use it or not ...
... at their own peril. (chuckle, chuckle)

[note - rant condition alpha is OFF]

cheers,
dr geep
;=]

Remember ... "With Poser, all things are possible, and poseable!"

cheers,

dr geep ... :o]

edited 10/5/2019

I usually shoot at the tightest possible f-stop... but my usual subject is alpine wildflowers (10 violets to cover the face of a dime) and so maximum depth of field is more essential than light. It's just a longer exposure. I'll brace and hold, although I'm not as steady as I was a few decades back. Since fstop controls both the amount of light (exposure time) and depth of field (area within focus), it gets really complicated really fast. Film is sensitive to exposure times and will change color with longer exposures (something which won't affect us in this virtual world). However, there are some neat things you can do with real film (backlighted silhouettes and waterfalls flowing like milk and trailing stars) which are quite tricky to fake. If we can get Poser 5 to behave more like a real camera, I'll be tickled pink. So, thank you all! Carolly

Here's an approach to measuring or at least getting a feel for the DOF using the MeasureIt script (available in FreeStuff). I built a checkerboard grid in Photoshop (attached) and applied it to the ground plane. I used the script to measure the distance from the camera to the origin of the ground plane then used that as the value for the focal distance in the Render Options window. Setting this up is described in the next message.

Setup:

The Main camera's orbit and dolly values where all set to 0 and the script started. If you haven't used the script, it works by measuring the distance between the pointed ends of a couple of props built by the script. The props can be moved around and the distance between them is displayed in a TKInter panel. The Pointer2 prop was moved 1.1 PNU along Z, that's the distance from the front of the Main camera to the origin, and then parented to the camera. The Main camera was set to point at Pointer1 located at the origin of the ground plane. The attached image shows what this looks like using the Aux camera. Pointer1 is hidden in the image but is located at the base of the red '4'. The first test is in the next message.

The 50mm image:

This first render shows the result of rendering with the camera set at 50mm with an f-stop of 1.001. The odd f-stop number was chosen to give the most compressed DOF possible. To set this up, the main camera was x-orbited to -18 degrees. When the camera was ready, the distance from the front of the camera to the origin was displayed by the script and entered into the Render Options window. You can see a nice clean in-focus line that runs the length of the x-axis. Just to make certain that setting up the camera this way would hold up with an even more compressed DOF, I set the focal length to 1200mm and tried again. Results are in the next message.

The 1200 mm image:

The result here turned out better that I had expected. Again, a nice clean in-focus line running along the x-axis. You can also see how the smaller checkerboard has more squares that are going out of focus. By rendering larger images, you should be able to put a reasonable estimate on the actual DOF over a range of focal lengths.

I did find it a bit odd that FireFly rendered the DOF along the entire length of the x-axis. In a real photograph, the DOF should look circular with items near the center in-focus and items out on the edges not so. Guess that's a limitation of FireFly. I also found it interesting that the DOF is apparently the same distance in front and in back of the focal point (in this case the origin of the plane). Usually the DOF is greater behind the focal point. It may be interesting to try a short animation using frame by frame distance values by this method. If I work one up I'll post it.

::: Watching in awe ::: Coolest thread ever

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Great info oh Divine Bushi, whose name must also be whisphered with awe. What you said about the DOF apparantly being the same distance in front and in back of the focal point is what I have been experiencing, and hoping to overcome. If this is a limitation of firefly than it would explain why so far no settings I have tried has allowed me to get the kind of gradient fade I had been hoping for. sigh.

Is that the best way that the depth of field can be rendered? it looks a bit low resolution.

@xantor - No, the renders where done with the pixel samples option set at the default value of 3. Higher settings greatly increase the render time but the out of focus areas look more realistic. I have a render cooking with the sampling set to the max (12) and I'll post it when it's finished.

Here's the render with the pixel samples option set to the maximum. There is still some grain but this was rendered directly to the main window. If the render was done to a new window at double the current size then reduced, the grain would be minimal.

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Could some one test this for me. So far the few minor test I have done have worked, but that is mainly on the WIP that launched this thread. I am in the process of doing a full blown render so my computer is tied up at the moment, but this seems to work.... What I did - and this use to drive my math teachers crazy, and I was okay until they asked me to SHOW my work. grrrr! I always got the right answer, but they marked half off for doing it the wrong way. grrr Okay, here it is in a nutshell Figure I want in focus is at the following x, y, z z=2.021, x & Y = 0 (this is the BODY locations, did not use the hip to place, but would be similar) Here is my Main Camera at 55mm x, y, z Dolly z= 9.617 y= 3.019 x= .246 Now cause I suck at math, I did the following and roughly added the x, y, z, camera values together and came up with the sum 13 rounded off From this I subtracted the figure Xtran 2(.021 dropped) and came up with 11 Next I open the render option and set the fstop to 16 - why, because dimly in the back of my mind I seem to recall that f16 was a good general setting for the kind of DOF I wanted. In the focal distance slot I insert - yeap - 11 I now render, and the render turns out right. I repeated this using a couple other items in me scene and seemed to get similar results. Now I am wondering, is this a Fluke? Or is it just that easy? [scratches head and hopes Poser Gods do not cast lightening bolts his way]

Oh, one thing I should clarify. The reason I subtracted the figure xtran is because it was a positive value like the camera dolly x, thus putting it closer. Had it been a negative value, thus farther away, I would have added, in order to get the approx distance from the camera to the figure. No, it probably does not make sense to anyone else but me. :O)

Book Mark*

Another way of expressing the formula for the distance between two points is:

the square root of ((x2-x1)**2 + (y2-y1)**2 + (z2-z1)**2)

So plugging in your values gives:

the sr of ((0.246 - 0.0)**2 + (3.019 - 0.0)**2 + (9.617 - 2.021) **2)

the sr of (0.061 + 9.114 + 57.699)

which gives 8.178, so I'm not at all sure why your value of 11 works. Did you try it with a small f-stop number to see if it still works with a smaller DOF?

Hi bushi, I did some limited tests using the box set up softriver posted at various fstop settings. It seemed to be working, but how well I am not sure. I picked different boxes at different locations and did my bad math to come up with a sum to plug in. Again, in my strange little world of warped thought, it makes sense and seems to work. Whether or not it will work for others or is anything more than just a fluke remains to be seen. As for the math you cited, I will try a value of 8.178 in my art render (which is where the original values I cited came from) and see what happens. Maybe I just lucked up and was in close enough focal range not to tell the difference. Shrug. Me and NSG have a lot in common at times. :O)

@shadownet Hey, if it works for you then it works fine. :-) The formula I used is the same as in the MeasureIt script. That doesn't say though that it's the ultimate answer here only that the formula gives the distance between two 3D points. Which points to pick is the hard part ...

I agree, if it works it works. My logic is that the main camera zeroed is at 0 x,y,z And when I load a figure its default is normally 0 x,y,z So if I move the camera or figure away or in toward, i.e -0 or +0 that is the difference in the distance. Since reality is often a product of our own mind, and since I have been accused at times of living in my own world - this logic makes perfect sense to me. LOL Even better, it seems to work. :O) Which, btw, 8.178 did not, and my figure ended up out of focus.

Hmmm ... re-reading the discription of your original setup I can see why 8.178 didn't work for you. That calculated distance was from the camera center to the point located at 0,0,2.021 which is on the ground plane. Your intended point of focus was up off the gp probably the figure's face. That would change what the second point for the formula would be. If you would and if you still have that original setup, would please check the camera dolly xyz locations and if there are any orbit xyz values. I'd like to try that with the MeasureIt script after this last render is finished. It's been going about 4 hours now but is almost done.

@bushi, (crawls prostrate warily back toward the altar thinking that was really spooky) Right after my last reply, 3 tornados touchdown around us, the power went out, so naturally I lost my nearly finished full blown render in process. Will have to start that one over. Did not loose the file though, so have the settings for you. Yes there were some orbit values. Main Camera 55mm DollyZ = 9.617 DollyY = 3.019 DollyX = .246 z,y,x & scale (all) 100% z&x orbit = 0 yOrbit = -41 Figure Body x,y,z Rot = 0 xTran = 2.021 y&ztran = 0

This is a low render version of the picture that sparked this thread, for anyone who might be interested. Wish it were better for such an auspicious occasion, but from such lowly beginnings still great things might come as far as end results on the DOF study.

This was rendered to the main window at fstop 16, focal distance 11, paint bucket at 5 (the fade is still a bit grainy) hoping a larger render with higher bucket setting will help.

@Shadownet- If you could do me the kindness of posting the position of the mirror, and the bearded cupid figure, I'd appreciate it. Your render has sparked me with a strange idea, and I was wondering if Poser has the internals to pull it off. (i.e. What if the reflected image is in the focus area, but the reflected object is not?) Maybe I'm making things more complex than they are, but it seems like there are a lot of factors on how the reflected image would display in ray-tracing versus real life. (i.e. Does Poser use the distance from the mirror to the camera to determine the focal length, or does it use the length of the ray (object to mirror to camera) to make that determination?) Looking at your image, I think Poser uses the length of the ray, but it's hard to see clearly. On the larger hi-res version, look in the background of the mirror, behind the short fat guy. Is the background blurry? @Bushi - I've been having trouble with the focal distance spreading out all along the x-axis as well. It's really confusing me. In real life, there should be a sphere around the camera lens with radius=focal length. But with Poser, it's just a flat plane running perpendicular to the vector described by the camera's facing. This is a serious limitation in certain types of images, but maybe it can be put to good use in another way?

Softriver, okay will get those setting for you shortly. The best hi-res version I could get so far was with a pixelsize of 5 at 800x600. Not very hi res, but my ol puter puters out. Hard to tell off it with any real certainty, but it does not look like any image blur in the mirror background. Even in this pic the DOF is not that good, but is the best I have gotten so far in all my tries. At least in this one, using my crazy method of calculation, I was able to keep the foreground and main figure fairly crisp, with the background fading. I think Dante may have had Poser in mind when he penned The Divine Comedy.:O( Oh, about your tests. I have the first 10 done, and 9 of the second test. Not been able to do the 70mm 1 fstop test render cause my puter gives up and P5 just reaches a point in the render and stops like it is done, only it isn't. I think it is time to upgrade. Not had time to try the 2x the focal value test, but have a feeling my puter is not going to be able to pull it off.

@softriver Mirror Y rot = -8 x rot = 0 z rot = -3 xtran = -0.542 ytran = 0 ztran = 1.402 (all scale - if needed - 100%) Cupid y rot = 44 x & z = 0 xtran = -1.308 ytran = 0 ztran = -3.105 Yscale = 70% all other scale 100% Oh, error in comment about about paint bucket size 5, er, that should be pixelsize 5. Duh. So, is any of this DOF beginning to make sense to you. Except for my bit of crazy calculations, how Poser does the DOF does not make much sense to me or seem to resemble what I remember of real world camera settings.

OK, this is an example of having the pixel sampling set at 12 and the image rendered to a new window at twice the size of the final. It was reduced in PS with a little croppping off the top. The render time on this ended up being around 5 hours with most of the time spent rendering the bottom quarter. With the max pixel sampling and reduction of any left-over grain by resizing, FireFly can give a reasonably simulation of DOF.

@shadownet - Thanks for the info on the camera settings. I'll try them out later today. Oh, and keep your head down! :)

That looks really good bushi! I wish I could render past pixelsize 5 800x600, but anything higher than that and P5 just stops in mid render like its done. Oh, btw, going back to the 8.178 at post 120. I tried that setting again, only this time with an fstop of 32. Worked. My calculation, however, at the same setting was a bit more blurry on the figure, unlike 16 and 8 fstop. There is definitely a bit of Poser weirdness going on here in how P5 does DOF, but I am encouraged by your results. :O)

Attached Link: http://www.shuttercity.com/DOF.cfm

Hey All, Travelled today (busiest day of the year they say). Rought flight too. Came across a link from, I think, RuntimeDNA, to this site http://www.shuttercity.com/DOF.cfm Kind of a neat do-hicky. Don't know if this helps or not. Best Wishes and Happy Thanksgiving, Rance

Hello Everyone, softriver, I've taken one of my older files and modified it a bit for this forum. It actually included a mirror so I thought I'd do a little test. Here's the stats: DoFTwo Main Camera Focal 55mm xTran 1.354 yTran 3.665 zTran 9.514 xOrbit -6 yOrbit -25 Mirror xTran 4.499 yTran 4.340 zTran -5.867 yRotate -1 xRotate -5 Don (Body) xTran 5.849 yTran 0 zTran -1.178 yRotate -158 Production quality, FireFly Use Dispacement Raytracing Smooth polygons Pixel samples 12 Depth of Field F-Stop 1.4 Focal distance 26.48 I used Stewer's script to calculate Focal distance. The default F-Stop of 2.8 didn't generate much effect so I chopped it in half. The image was rendered at 800x600 pels, .TIFF and resized to 600x450 and saved (20% compression) to .JPG btw, the chest figure/prop is DAZ I think.

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