Can someone explain lens cast by aperture to me

Started 4 months ago | Discussions thread
ProfHankD Veteran Member • Posts: 7,522
Re: Can someone explain lens cast by aperture to me

fferreres wrote:

E Dinkla wrote:

That colors are shifting between wide open and one or two stops closed I see in more of my lenses. But the scene you show here + different exposures it seems, may as well trigger some differences in scene interpretation of a default setting for image development, whether in the camera or afterwards.

Met vriendelijke groet, Ernst
No photographer's gear list is complete without the printer mentioned !

I developed from RAW and made both images use the same white balance temperatures. I also tried FastRawViewer and they look the same. The In camera thumbnail (embedded in the RAW) looks the same.

I wasn’t surprised by some shift. Hank has mentioned a few times with some vintage lenses. But I had hardly noticed anything to this intent.

Really, if you display each image fully, not the thumbnail, the photos are day and night with regard to the mood they convey.

As I said above (and in general WRT this), usually the stopped-down one has the more correct colors. If you separate-out the color channels here, the blue channels actually don't look that different: it's the red channels that differ wildly.

The difference is really contrast, especially on the red channel. If you look carefully, the noise level on the red channel is much higher in the wide open shot than in the stopped-down one. In fact, the red channel is far noisier than the other channels in the wide open shot, but not in the stopped down one.

To me, this suggests that the scene naturally had almost no reds except where the light directly hit -- like the stopped down red channel shows. However, with a wide-open shot containing less blue, the red channel was boosted. It should be much clearer what's going on if you look at the raw directly (before color interpolation and white balancing). In other words, I'm saying your white balance transformation made this more dramatic than the difference really was.

BTW, odd aspect ratio on these.

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