I have struggled with this for the last few months, and I am about to put it aside. Their is no tutorials of lighting of using lamps in a room. Every tutorial or samples is all modern and living the high life rooms. So clean, and in daytime. Saying to myself, well it would be kewl to make a render in image from the late 60s or early 70s in a mid class life. Not high, or poverty. Just that average family life, who only could afford that station wagon. Myself been in homes, where a ceiling light would be glass, square, and light up the room brightly, then if you use lamps will do some of the same. I just unable to get it using emmision. Curtains are closed due to family privacy, or opened with street lamps helping. Then I get blotchy spots on walls, ceiling, grainy, light not bright enough, or to much. It is a huge struggle.

With curtain open. Street view.

Need a lamp cover shade I had to make to help?

I struggled with lighting interiors as well. What sort-of came out of that was someone mentioned the use of portals as a means to 1) cut down on render times, since light rays travelling out the window don't really need calculating, and 2) checking your ambient occlusion distance settings in the World settings. Not sure if that helps, but just saying: I relate to your frustration.

Yeah, was doing that for day renders. Here is an image I used for daytime using portals in windows glass. And you can see blotches on floor walls, ceiling, all over. So, decided to make evening. but where would I use portals? I did on top ceiling light (didn't help). I have light bulbs as emission inside lamps and top ceiling. Wanting that realism.

maybe have a look at this video/tutorial?

https://youtu.be/m9AT7H4GGrA

Thanks FrankT. I have seen all of Blender Gurus videos for years, over and over. Nothing on lamps, Ceiling lights, evening indoor scenes. About to go onto other project, and leave this one.

I do use some of Blender gurus samples from his tutorials.

Hi Robo2010

Domestic lighting was totally different back in the 50's and 60's to what it is now. It was mainly incandescent 25W to 60W with occasional 3000K or 4000K fluorescent mainly in kitchen areas. Most lamps where either 25 or 40 while ceiling lights where 60. Although this is not exact as wattage doesn't relate directly to colour etc but a 60W incan bulb is roughly 2750K and a 40W around 2500K . I notice your light colour looks really white. White light doesn't start till about 5000K and was unheard of in reality in domestic homes back then. A 60W is a yellowy orange colour. You would never notice that they are not white until you held the different wattages and coefficiants up against each other.

This may help with the first image and playing with the falloffs a bit may as well. The open curtain one looks as if its daytime outside instead of night Hope some of this helps.

Incantrix

Using black body nod helps with lights using the scale variables. I have it set at 2800.

This fellow has some clever ideas...

https://www.youtube.com/watch?v=OHisRVyczgE

I have found Wayward Company pretty much spot on with their suggestions. Worth a shot, anyway... he says initially: "I don't want the HDRI to overwhelm the interior lights" - sound like what you want to do.

Well, keep trying to solve a evening in a living room (late 60s, early 70s) scene. This is my result. Lots of struggling, and yes some sleepless nights. The ceiling light fixture is another problem, that I can not solve, and will leave it for future blender, Version 2.8.

Note When I first started this, I had no problems with HDRis and outside lighting. Now, when using HDRi and lighting, all of a sudden (now), I am getting light going through walls. floor, ceiling. I thought I had it solved earlier, and the problem came back. Never was a problem before on this project. Is is due to saving a project the mesh loses its features or gets messed up on the loading? I dunno, I am putting this aside and now onto Halloween.

Earlier render. 70s.... Tried other lighting techniques. :-)

and Top ceiling light. Doesn't give that 70s feel.

8-track stereo, tables, speakers was fun to make. Phone is a freebie (think at DAZ).

Bit of nostalgia, looking at your rooms. Well done, nice work!

WRT light bleeding in: when I had a similar problem, I found I had duplicate verts and shared (not closed) edges. Not sure why doing a [W] - {remove doubles] fixed a light problem, but anyway, FWIW.

Now you've just made me feel very old.