Lightbox brighter than collage

StueveShots · June 5, 2014

I just noticed something strange and I wonder whether it is something I have inadvertently done. The pictures in my galleries (which utilize the landscape collage setting) appear far dimmer and duller than the same picture when viewed in the lightbox. Why is this?

thenickdude · June 5, 2014

They look identical to me. I compared the brightness of the white around the horse in this first photo on both the lightbox and in the gallery using screenshots, they were both pure white, 255,255,255. Which browser and version are you using?

StueveShots · June 6, 2014

I am using Firefox on a PC and Safari on an iPad and Mac and see the same thing on all three...although, strangely, not on the picture you chose to examine. I also use a 30" Dell monitor with the PC (which is always calibrated--I work with graphics almost daily).

Would you mind seeing what you experience with this shot? Thanks! Meanwhile, I'll check on other galleries using other browsers... Maybe it is all in my head!

Jtring · June 6, 2014

I've occaisonally sensed something similar on my site, and I've attributed it to the differing resolutions. The lightbox version of the Just Jonathan shot shows more detail -- more little variations on the skin texture and more little points of shine -- than does the smaller collage landscape image where these get averaged out. That extra detail adds extra vibrancy. On the horse shot, the visual effect of the plain black background in the lightbox compared to the lighter and more complex visual context in the collage landscape array may also comes into play. I don't think it's "all in my head", but some is. And that shouldn't be a problem: vision combines optics with signal processing by the brain.

Jim Ringland
jtringl.smugmug.com

StueveShots · June 6, 2014

Thank you, Jim. That makes sense--particularly when I consider the visual complexity of the collage format. I guess I just need to decide if I want to stick with it then...

thenickdude · June 6, 2014

As Jim says, it could easily be due to photos in the collage view having more bright detail around them. But note there is also a technical reason why photos with lots of fine detail that are scaled down using most software appear dimmer than the originals. It is due to a pervasive bug in photo scaling algorithms, and even affects Photoshop:

http://www.4p8.com/eric.brasseur/gamma.html

(though the effect is slight for most images)

Jtring · June 7, 2014

thenickdude wrote: »

... there is also a technical reason why photos with lots of fine detail that are scaled down using most software appear dimmer than the originals. It is due to a pervasive bug in photo scaling algorithms, and even affects Photoshop:

http://www.4p8.com/eric.brasseur/gamma.html

(though the effect is slight for most images)

Interesting article, although he's maybe a bit long-winded in getting to the point that when reducing resolution, one should apply the weighted average algorithms to the luminosities associated with the 0-to-255 numbers, rather than directly to the 0-to-255 numbers themselves.

The discussion also suggests that the SmugMug X3's and X2's could be a little dimmer than a much larger original. I think I've seen that too. I typically do my processing in Lightroom, upload an original-size image, and then do some fine-tuning based what I see when viewing the screen-sized version of new upload in the lightbox. I note that sometimes -- not always -- I want to up the brightness by a notch or two at this last step. That's consistent.

Jim Ringland
jtring.smugmug.com

Lightbox brighter than collage

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