color and contrast matching between two images

[Roger Clark]

Hi,
I'm doing an experiment of comparing 5D2 images to medium format (6x7) images with Fujichrome Velvia scanned on an Epson V700. It looks on first examination that the 5d2 images are sharper, but the colors of velvia are stunning.
So is there a way (e.g. in photoshop) to match the colors and contrast of the 5D2 to the velvia image? E.g., it would be nice to click on a few points in each image and derive the transfer curve then apply it.

Roger

[James Shadle]

Roger,
Fred Miranda has a Velvia plug in for photoshop.
You can do a lot of fine tuning with it and it's easy to over do:).

You run it through the automate panel rather than as an action.

James

[Dave Taylor]

Hi Roger,
I was just perusing some of the older posts and came upon your question. I wanted to do just that a while back. Wanted an algorithm comparison between my camera and a Velvia image of the same scene - then just make an action to bring the digital file in line with the Velvia one. I think the problem we're going to have is the fact that there was no variable color space with film. Velvia has a fixed response to color temperature, as did all films. Whereas digital is like the human eye, it picks the brightest highlight in a scene and balances that as a neutral white. So while an algorithm might work very well for a single image or setting (location, steady and unchanging light source like a studio setup), as soon as the color temp changes it would probably rendor the algorithm less accurate in the least, and completely off at the worst. Hope that helps.

[Roger Clark]

Hi Roger,
I was just perusing some of the older posts and came upon your question. I wanted to do just that a while back. Wanted an algorithm comparison between my camera and a Velvia image of the same scene - then just make an action to bring the digital file in line with the Velvia one. I think the problem we're going to have is the fact that there was no variable color space with film. Velvia has a fixed response to color temperature, as did all films. Whereas digital is like the human eye, it picks the brightest highlight in a scene and balances that as a neutral white. So while an algorithm might work very well for a single image or setting (location, steady and unchanging light source like a studio setup), as soon as the color temp changes it would probably rendor the algorithm less accurate in the least, and completely off at the worst. Hope that helps.

Hello Dave,
While what you say is true if you are doing auto white balance, it is not true if you shoot a fixed white balance or shoot raw. The advantage of digital is we can post process changing the white balance. Those algorithms did not exist in film days, but you can even do that now with scanned film. Just bring your image into a raw converter like bridge (e.g. even a tif or jpeg file) and you can manipulate the settings just like a raw digital file. The only problem is the noise is higher and the dynamic range is usually less (especially slides) so you can't push things as far as one can with digital.

I solved my problem by using curves and got the two images reasonably close. But this was by hand with multiple tries and only came out as an approximation, so I would still like to find a better solution.

Roger

[Dave Taylor]

True Roger - I do shoot most (almost all) of my images in AWB on RAW - then worry about minor corrections in Lightroom.I guess what I was trying to say, is that it would almost always be an approximation, like you said. Because, even with a custom white balance - it is still your interpretation of a scenes color temp, and not a fixed response like film would give us. That is one of the things that I actually miss about films like Velvia. Snow in shadows with punched up blues, deep reds in warm light, ahhh the good ol' days:)
I too made a development "preset" in Lightroom 2 that gets me close to Velvia like effects, another one for Kodachrome. But they only "get me in the ballpark", and I still end up doing further adjustments for each image.

[Roger Clark]

True Roger - I do shoot most (almost all) of my images in AWB on RAW - then worry about minor corrections in Lightroom.I guess what I was trying to say, is that it would almost always be an approximation, like you said. Because, even with a custom white balance - it is still your interpretation of a scenes color temp, and not a fixed response like film would give us. That is one of the things that I actually miss about films like Velvia.

Dave,
What you are describing are post processing decisions. But the underlying digital sensors do have a fixed response, and in fact more fixed than film. With film, you had variations in response with film batch, storage time, and chemical processing. Digital sensors are much more stable. So if your digital processing were consistent, you can get stable and consistent results with digital, and even more consistent than film.


Snow in shadows with punched up blues, deep reds in warm light, ahhh the good ol' days:) I too made a development "preset" in Lightroom 2 that gets me close to Velvia like effects, another one for Kodachrome. But they only "get me in the ballpark", and I still end up doing further adjustments for each image.

I agree. What I was trying to do was show a comparison of 6x7 velvia compared to 1D Mark II images. The results are details are very similar, but color of course is very different and it takes some work to get those spectacular colors of velvia. I'll be putting up a web page about this in a month or two, when I get more time. I'm also thinking of doing an analysis of registered velvia and digital images so I can derive an accurate transformation between the two. But in the end, when I was massaging the digital to match the velvia, I found I could make the digital look better than the velvia. The scene did include snow in shadows, and the vevia looked too purple in comparison. So I'm hoping to come up with a transformation to to get close to velvia, but better ;).