Colors of architectural surfaces

[Leonard Evens]

I've been photographing buildings using Portra VC 160. I scan using Vuescan on an Epson 3200. After some adjustment in a photoeditor, I don't have too much trouble getting vaguely plausible colors of building surfaces using neutral elements of the scene. I also photograph a gray card with a digital camera, and that helps me get a bit closer. But I still am not close enough to what I feel the actual colors should be. This is particularly a problem when I use wide angle lenses and the building surfaces show significant variations anyway. Strong colors usually don't present as much of a problem as various shades of "off white".

There are a variety of problems, which I feel I don't completely understand. I use a center filter, which reduces intensity drop off from center to edges, but it appears there may also be a slight color shift which remains. In addition, I think the quality of the reflected light may vary depending on the angle to the lens. On top of this, the natural variations in color already present complicate matters, as do deficiencies in the film, the lens, and the scanning process.

I would appreciate any pointers to help me understand these issues and websites showing examples I can copy and measure.

[tim atherton]

leonard,

have you tried using NegPos with vuescan for colour negs? I find it excellent

(bit of a learning curve - lots of info on colour negs on the site - quirky vuescan like interface...)

tim

[Gordon Moat]

Hello Leonard,

Recall that colours on a computer monitor will only be a simulation of what a printed output might show. If you are only processing the images for internet, broadcast, or multimedia display, then don't worry too much about slight variances; most viewers will not have their monitors or televisions even remotely close to proper specifications.

With print output, you should be judging the actual print, or an approved proofing output. Anything near light green, to near Cyan, just will never properly display on any computer monitor. Certain inkjet printers and paper combinations will show differences in subtle tones depending upon several combinations, or even environmental factors.

If you can be more specific, or post a link to an example, I might have more specific suggestions. The best way to test a centre filter is to photograph the same scene with the filter in place, and then with it off. If you are doing adjustments in post, you might find that shooting without the centre filter, then creating a mask to mimic the filter might work better.

Feel free to contact me off group, or to reply here. I don't check here that often, so if this is time sensitive, just e-mail me.

Ciao!

Gordon Moat

[Tom Westbrook]

I second the NegPos recommendation. I checked it out after Tim recommended it a while ago and am very happy with it's perforance. They have an evaluation verion on their site (tho you get a newer version if you buy) at http://www.c-f-systems.com/Plug-ins.html.

[Kirk Gittings]

I don't find Neg/Pos useful over a good scanner software combination like Silverfast and one of the higher end Epsons or Nikons.

I need to know a little more about your shooting methods. Are you using strobe fill in daylight or just natural light or quartz fill or what?

[tim atherton]

kirk and I are at opposite ends of the spectrum on this - I've never really liked silverfast, nor have I found their film profiles to be that great (for colour or B&W - and I've used it with a number of different higher end scanners) - he's not so keen on vuescan and negpos....

[adrian tyler]

tell you what thiough leonard, whatever architectural surfices you shoot it can't he worse than frank gehery's "marques de riscal" wineary in the north of spain. i have been working on the project for 3 years and he has uses 2 different tones of titanium, stainless steel and sandstone. the colours in the titanium change subtly evey minute of the day, 365 days a year.

http://adriantyler.net/ficha.cfm?idcategoria=35

(very crude edit)

back to your question, use a reference in the picture that you are familiar with when printing, grass, flowers, granite, rust, whatever. i find that if i print to get that right the rest more or less falls into place.

[Kirk Gittings]

True Tim, I don't find anything in Neg/Pos that I can't do in SF, including developing and saving very detailed personal profiles for particular films. The Sf profiles are a good starting point but I can tweak them to my hearts content.

Plus scanning the negative basically as a neg transparency in a raw state and converting it to a postive in a PS plug-in (Neg/Pos) generates more noise in the transition tonal areas than being able to apply curve adjustments at the scanning stage in SF. Any workflow that includes significant contrast enhancement after the scan in PS will greatly enhance noise. The more noise in the original scan the more it will be enhanced by a steep curve in PS, so the Nikons are better for instance than the Epsons because they have less noise in the original scan. No matter what I did the N/P workflow produced significantly inhanced noise over the traditional SF workflow because the major curve adjustments are applied in the scanning with the SF method I suggest vs. a flat raw scan for the N/P workflow with contrast enhancements latter in PS. Based on yours and others recomendations, I really wanted N/P to work but after a couple of weeks of testing it I came to the conclusion that it was an inferior workflow and that was true whether I used Sf, ES or Vuescan to generate the original scan.

Some have suggested in the past discussions on this forum that only in N/P can you tweak the individual color channels while viewing all channels simultaneously and that only in N/P can you develope and save your own profiles. These are false assumptions by people who do not fully understand the capabilities of SF, because both are easily accomplished in SF.

[Kirk Gittings]

A couple of the tricks we apply to control color shifts (beyond problems with scan profiles).

Put a small greycard in the scene in an place it is easy to remove later in PS. Use the middle grey eyedropper in Curves to nuetralise the mid tones and key the colors overall or do the same in SF in the scan.

COLOR MECHANIC PRO, COLOR MECHANIC PRO, COLOR MECHANIC PRO, COLOR MECHANIC PRO. Let me be clear on that-use the PS plugin COLOR MECHANIC PRO. It is the production architectural photographers best friend.

[julian]

Some have suggested in the past discussions on this forum that only in N/P can you tweak the individual color channels while viewing all channels simultaneously and that only in N/P can you develope and save your own profiles. These are false assumptions by people who do not fully understand the capabilities of SF, because both are easily accomplished in SF.

Didn't ay that Kirk - or if i did i didn't explain myself well. I said that only in negpos can you calibrate and manufacture your own convert profiles. I've seen this discussion a lot and I think it boils down to whether you like to treat a film scanner like a drum scanner and do all the colour in the scanner software, or if you want the scanner software to not meddle with the data and manage the data in photoshop. IMO there are damn good reasons for the drum scanner workflow IF you use a drum scanner and less so for a film scanner. I know Kirk uses smaller print sizes than I do, but a 1mx1m print from a neg I see much richer tonal values, smoother transitions in negpos than in sf. But hey, whatever works for you