Sheedee opened this issue on Jan 19, 2013 · 9 posts
Sheedee posted Sat, 19 January 2013 at 10:17 AM
I am using BB Env Sphere with an HDR image attached for light and reflection purposes.
As you can see with the default camera focal lenght the main objects look normal.
But for the purposes of showing off the HDR image and making it less blurry, the focal camera lenght has to be reduced quite a lot...which initially is not a problem...the only catch is that the subjects get distorted.
Is there a work around to this?...
Thanks for viewing.
ErickL88 posted Sat, 19 January 2013 at 10:33 AM
What would happen, if you simply reduce the size of the envspere?
Santel posted Sat, 19 January 2013 at 10:53 AM
if your looking for accuracy, the your lens in poser should be as close in size as the lens of the photographer who made the hdri image, which is often 25-28 mm.
monkeycloud posted Sat, 19 January 2013 at 11:04 AM
I quite often just move the envsphere back (away from the camera) on its z-axis to achieve an effect approximating this.
Reducing the scale of the envsphere, from the default 100%, to say 10%, only makes a slight difference, I've found... although it can have some effect.
I suspect that scaling the envsphere on just its z-axis (or the axis receding from the camera) might have a similar sort of effect... although a slightly different effect at the same time... not tried this last idea myself yet.
hborre posted Sat, 19 January 2013 at 4:49 PM
Try a focal length of 35mm for the camera lens; it is a better compromise than using a 28mm or lower.
Sheedee posted Sat, 19 January 2013 at 5:00 PM
Even when the camera focal lenght is reduced, the HDR is not crisp and sharp...
Are there special HDR imsges that are perfectly sharp and even stay so when attached to the sphere?...
Any links?...
Thanks for viewing.
View image at full screen...the cab prop i added myself, btw.
Medzinatar posted Sat, 19 January 2013 at 5:23 PM
Quote - Is it possible to obtain HDR images that are even sharper?...really crisp?...
You have never mentioned what size map you are using, so it would be hard to say.
Keep in mind that the Envsphere is about 225 m in radius, making circumference 1400 m.
If your map is 1024 wide, then you only have 1 pixel about every meter.
FOV on 35 mm camera is about 54 degrees, so the amount of sphere you see in viewport is 1/7 of total. For 4096 pixel wide, you are only seeing 600 pixels or less.
HDR images come in all sizes, you just have to figure what size suits your needs
lowpoly posted Sun, 20 January 2013 at 1:22 AM
Size of render plays a part in the perceived sharpness.
If your HDR image is 4096 as above, FOV includes 614 pixels with 35mm focal length.
If your render size is 1228 pixels wide, it will have to stretch those pixels by 100%.
Unless you need the actual reflected image, you might just consider unchecking the "Visible in Camera" box on the Envsphere and compositing in background in postwork
estherau posted Tue, 22 January 2013 at 3:31 AM
If you have vue you can make some HDRIs by using panoramic render/spherical and picking HDR as the image format.
I aim to update it about once a month. Oh, and it's free!