How do you meter Portra 160VC?

[Juan Valdenebro]

I saw similar behavior with respect to saturation from Portra 160NC, 400VC, 400NC, 800, and Ektar. I did tests of them all.

The caveat to these tests is that I did not adjust the color, contrast, or anything else. I just posted the lab scans as they came in. You can download the original sizes of all the files though and tweak them yourself if you'd like to see what you can get out of it. A couple of curves in Photoshop actually goes a long way to restoring contrast and saturation on the heavily overexposed shots.

Latitude as I know it is not the range you can shoot the film and get ideal results. Instead, its the range you can get *usable* results. I think Kodak gives 160VC a latitude -2 to +3, and I'd have to agree with them - any of this pictures are useable, though I certainly like the ones shot closest to box speed the best.

Hi Tim,

Those very dark -2 and washed +2 and +3 are not usable. (OK, to me...) Why use those three inferior tonal ranges if there are three better?

I did test Ektar when it came out, and I shoot it metered incident at 25 since, because at +1 the color gets better, and at +2 (warming filter on) I get the deepest color, and it doesn't get washed as this thread's test seem to show about Portra 160 VC... I'll test 160, because that test is strange: film saturation and desaturation seem inverse: like that of slide film...

Cheers,

Juan

 

[Tim Gray]

I agree they aren't preferable, but they are useable. If one accidentally shot a picture two stops under and still wanted a print, with not too much in the way of photoshop work, I think you could end up with something quite nice. Meanwhile, two stops under (or over) on slide, and you've got a real mess on your hands.

I've heard the thing about overexposing color neg increasing the saturation, but I've personally never seen it. This might be because all my color neg gets scanned and not printed in the darkroom; I don't know. In fact there was an APUG thread on this very thing the other month.

 

[Juan Valdenebro]

Thanks for the link, Tim...

When I printed (wet) on color paper (for several years) both overexposure and overdevelopment used to increase saturation.

But my Ektar testing (2009) was done with lab development, scanning and printing, and after my previous, direct order to the guy scanning and printing: "don't correct anything because all I'm looking for is how to get cleaner and more saturated colors depending on exposure, so you can't touch levels, nor contrast... Of course saturation either"

Of course any lab can do lots of things without letting me know about it... But apart from being a pro lab I use 10 years ago, the results I got were just what normal C-41 behavior has always been, including the muddy colors and grainy look we get with underexposure...

It's really strange that on this thread's test, colors start to vanish by +1 as if it was slide film... I'll test the film tomorrow both on direct sun and in the shadows, to set my incident metering values for best color...

I think the lab doesn't decide an identical scan for all frames: they sure scan every frame, and the software takes part in the process to create a range from colors to blacks... I mean in the test for Ektar I already considered this, and was curious, but the results were just as if I were wet printing: horrible at -1, and cleanest, most saturated colors at +1 1/2, so I meter Ektar at 25 (incident) and use warming filter always... Another thing I clearly remember is that exactly the same rating was the one that looked better for direct sun, shadows and overcast.

I'll do a few quick snaps in manual (incident) tomorrow, with a bracketing of N,+1 and +2, and some AE of the same images too, just to check how my FE2 behaves... I'll be using 1/4000 for wide open shooting under direct sun without ND filter... So I better check the real shutter I'll be using for my 105 2.5... With NDs I can't focus easily on SLRs, and I plan to teach my 12-year old brother his first lesson with that camera-lens-film set... On shadows and overcast I can get enough speed too without needing another film... RFs and prefocusing with Tri-X with a 28 for relaxed composition or fast shooting, will be a second cool chapter to him...

Cheers,

Juan

 

[Juan Valdenebro]

I checked it again... Here's what I think (imagine) of that test:

The person who did it, wanted to use the same scanning for all frames trying to show real exposure on film... Then he decided the "all frames constant scan" from scanning frame N (box speed), and then, he scanned -preserving the previous scan settings- the rest of the frames.

My guess is that the procedure is a wrong one... It would be fine ONLY if in fact frame N was the best possible exposure... (and would be optimal for N only) But maybe the whole test is wrong, because all films' real speeds are a bit below box speed...

Scanning frame N (160) and using the same scanning for -2, -1, +1, +2, and +3, produced what's obvious: two clearly underexposed files and three clearly overexposed files... That's why even +1 looks washed...

I'd do the test differently: I'd allow the scanner try to get the best from every frame separately (in auto: finally that's what labs and homes do...), and then, without any digital manipulation, I'd lab print all frames on photo paper and forget about screen checking... On real prints we'd be seeing what we can get from a certain ISO rating used EVERY TIME, instead of seeing how a different ISO rating than box speed makes an image look after being scanned as if it was the box speed shot...

It requires images with a rich range of colors and whites and shadows, so the scanner doesn't need to expand any low contrast scene...

All color negative films I've tested before, behave the same way: -2 is horrible: dark, muddy, grainy, desaturated... -1 is near the same, but less evident... N is almost normal but the colors are a bit soft and off: a very slight blue or magenta cast that gives false skin tones and darkened grass' greens... +1 and +2 show the most accurate and clean colors, and a bit more saturation... +3 shows overexposure with a bit of color washing, yellow shift, and an unpleasing color gradation when colors reach their highlights...

I'll shoot now...

Cheers,

Juan

 

[Tim Gray]

I eagerly await your results. My test was done in 120, and I don't have a 120 scanner, so unfortunately I can't play around with rescanning at home. I did tell the scanner operator to do what they wanted to get the best picture on each frame. The test's purpose was for me to see how NCPS handled different films at different exposures and what kind of scans they could deliver.

I intend to reproduce a subset of these tests with one or two films on 35mm so I can bring the scanning part of the test in house.

That being said, in that APUG thread, Photo Engineer (an ex Kodak worker who used to design color products) does make a good point. In an ideal film with straight line response for many many stops, overexposing would not change anything, just slide the exposure higher up on the straight line. It's only because film has a toe, a shoulder, and other non-linearities allows exposure to affect our color (and tones). He did a test (its on photo.net) of a couple of the Portras, similar to mine, except he wet printed them. He got very similar results as I recall.

I guess the take home message is this - it all depends on the system *you* use. If your scan operator (or you) scans in a specific way, then maybe overexposure *does* mean more saturation. Or less.

The last bit I want to say concerns semantics - again, what it means to be 'usable'. If you wanted a pastel look from one of these films, I might recommend trying +4 exposure. If you wanted 'normal' color, I'd say shoot it at box speed or +1/2. One person looked at my results and said, "I like the -2 the best, but I like dark skies." Go figure. I still think you could make a 'usable' print of any of them. They are far better then what you might get out of whatever was loaded in a disposable camera 15 years ago and underexposed by a stop. THAT was unusable.

 

[Juan Valdenebro]

I guess the take home message is this - it all depends on the system *you* use. If your scan operator (or you) scans in a specific way, then maybe overexposure *does* mean more saturation. Or less.

I totally agree... We're not talking about just film, but about film + scanning... Before that, it was film + enlarger... Any scanning can define lots of things... The idea is, getting the cleanest and deepest color (this is VC...) with the shutter, before scanning and before using the also handy photoshop... If we look at N, N+1 and N+2 negative frames on a light table, densities are very, very different... They're as far away as slide film frames with a 1 stop difference... I mean, even if things can be done to make use of any of them, for sure one of them is the best exposure...

Cheers,

Juan