GX20 green leaf rendering

tr13 · 07-22-2009, 01:38 PM

During checking of new lens from fleabay (yes, it came defective :-) )
I made few shots and found obvious thing.
Two tested AF tele lenses rendered green quite unnatural, and I can't fix it completely by WB tool easeally.
But MF lens I have (80-200 F3.5) made all same images look more natural, yes, more cold.
Any ideas why?

davebris33 · 07-22-2009, 03:23 PM

Is your screen correctly calibrated, as the green in the first picture looks really good to me, and the second one looks way too cold!

but it is purely personal taste and to an extent how we remember the real world when in front of the PC...but the first one is what I would aspire to when PP'ing an image

Cheers

**Peter Zack** · 07-22-2009, 03:30 PM

Impossible to evaluate the differences without knowing something about the lenses. Plus I agree that the first image looks correct and the second has a blue/purple cast. The gray path in the first looks right but the second is way off.

tr13 · 07-22-2009, 04:04 PM

As for monitor calibration. No I didn't performed it. But at least I saw original :-)
Yes, second picture have slight purple cast, but only slight.
I didn't correct anything as that was not the point.
And color on first picture is unnatural glowing green, same on camera screen and my two monitors, not close to reality. You could see color histograms to check that second picture have indeed more accurate color balance. I used Photo-Brush white balance tools and couldn't make greens look similar.
I have similar thing on my old Samsung compact wich gives same unnatural glowing green contrary to perfect color on recent TZ5.

Lens used (at 200mm):
1) AF - Quantaray 100-300mm F4.5-6.7 (this is rebranded Sigma)
2) MF - Focal 80-200mm F3.5 (looks like Soligor C/D)
3) Not shown - Quantaray 70-300mm LD 1:2 4-5.6 (rebranded Tamron). Soft as hell. Looks defective. But colors are exectly as 1).

Both very cheap lenses, but I like both.

Daveinozbikes · 07-23-2009, 03:53 AM

Without the benefit of the real scene the first one looks OK and second one has blueish cast. Maybe your monitor needs adjustment.

ftpaddict · 07-23-2009, 04:01 AM

Originally Posted by tr13

Yes, second picture have slight purple cast, but only slight.

No no, not slight. A lot. Look at this thread on another computer; or using a different monitor. Either your monitor is off, or your eyes are.

tr13 · 07-23-2009, 12:03 PM

Just checked on my tablet with PVA screen, yes a lot better. But after WB correction second image is still closer to reality. Point is that purple cast is easy to fix using color histograms and shifting, but in first image histograms are much more off.
Main point of the post was different rendering with manual glass, more cold.
Same on M 50mm 1.7 and my other 50mm.

Class A · 07-31-2009, 01:09 AM

Originally Posted by tr13

Any ideas why?

FWIW, I also find the greens in the second image to be more natural (but my LCD screens are not hardware calibrated, just using test charts).

Here's an experiment you could try. Shoot the same scene for both lenses in RAW and use one and the same RAW developer with the same settings (i.e., don't let the developer choose the settings, including WB, from the camera).

If the difference isn't as big then the camera JPG engine would use different parameters depending on the lens type. Yes, that should absolutely not be the case but it would be worth eliminating that possibility.