color problems

[LorenzoS]

Hi guys,

I have this kind of problem and I can´t understand how to avoid it. I hope someone can help me!

In my screen the rendering looks perfect as this one:


but
when I am going to print, in some areas I can see some weird colors... somehow the gradients color on the walls are not soft. (thery are just white 244 244 244)
It is very difficult to explain how it looks like...
so I made here another screenshot, using photoshop I did some very HIGH contrasts, but it gives the idea what I am talking about...



any ides or suggestions?

thank you!

serra


p.s.
It is not a printer problem, because I am using a professional photo-lab.

[fooprobe]

Re: color problems

Things you might double-check:

Convert the file to CMYK before printing
Save in a 16bit or higher mode/format
If that doesn't work, try to calibrate your monitor to your print house's printer. Sometimes they can help.

What kind of printer are they using?

[LorenzoS]

Re: color problems

Hi!

thx Emil
but
I am 100% sure that is not a printer-issue because if I am looking (from bottom to the top) at my lcd-screen I can already see the wired color gradients...

any other helps?!

thx

[LorenzoS]

Re: color problems

p.s.
can I save from vray 32bit format image?
No?
yes?
how?

[fooprobe]

Re: color problems

the hdr format is 32 bit. not sure about exr but i would bet it is.

if you're seeing it on screen, do you see it in the v-ray frame buffer or just when you open it in your image editor?

[LorenzoS]

Re: color problems

already in the v-ray buffer

[fooprobe]

Re: color problems

I would otherwise guess that it's a monitor problem, but it's showing when you print so it's in the image. Saving 32bit probably won't help if it's in the VFB. What color mapping are you using?

Another way to diagnose this is to go back to settings that you know will work - presumably you aren't getting this on other renderings?

edit: also, what rendering engines and color mapping are you using? i don't see any GI shadows around the stool, are you using Light Cache? sometimes you can get a similar artifact happening with light cache if the sample size is too large...

[LorenzoS]

Re: color problems

Hi Emil,

here my settings:



thank you

[fooprobe]

Re: color problems

Try using DMC instead of LC for secondary engine and see if the effect goes away. The scene will probably get a little darker, don't worry too much, just see if the colors smooth out.

[LorenzoS]

Re: color problems

mmh nope,
it is not getting better....

[fooprobe]

Re: color problems

sent you a PM, check your inbox

[fooprobe]

Re: color problems

So Serra and I worked this out offline, and thought we'd post what came of it in case it's useful to anyone else. The problem turned out to be in the Irradiance Map settings, the HSph.Subdivs and especially Samples were set too low, so the quality of the blend between sample areas was poor. I've never seen a low sample value produce this effect before, just blotches, so news to me.