BetterPhoto Q&A
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Testing D&P labs

Anyway, I'm looking at testing out a few of the labs in my area. I've had some pretty varied results in the past, and sometimes it's difficult to tell if poor images are the result of poor film choice, poor focusing/exposing, or poor D&P. (See for example where I assumed that I got poor images from 800 speed film and underexposure, but ended up being the lab's miscalibrated machines)

The test photos have to be completely consistent, and I need to know what I can do to push each lab to the limit. So far, here's what I am photographing:

1) 0.5mm horizontal lines
2) 1mm grids
3) Targetting cross hair and circle
4) 1mm diameter dots
All of these test resolution

5) Colour wheel
6) Fleshtone
These test colour replication

I will be using a Canon 70-200 f/2.8 set at 200mm and f/8 (The theoretical sharpest possible settings on this lens) and ISO 100 Reala film to avoid any aberations from the lens itself.

Does anyone else know what other criteria I can use to test the lab?

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March 17, 2001

How do you do this? Shoot only on slide film for a while. Shooting on slide film will force you to become proficient at exposure due to its narrow latitude. Also slide film is less likely to become the vicitm of a poor processor. Most processing mistakes happen during the printing (auto printers or color blind technicians ;-))) ). With slides all they have to do is develop it and what you see is what you get. No questions. Once you feel confident in your skills then it should be easy to find a competent lab.

As to testing the labs I would suggest you test your films and find your personal exposure indexes for each film you want to use. Use the tests you outlined and shoot at different ISO's and find the result you like the best. Use that ISO for that film. Don't try to use too many different kinds of film. Pick a few to cover different situations and becoming intimately familiar with them. Learn how they respond in different light and what happens when you push them etc.

To choose the lab, first stay away from the lab you had the problem with. Quality control should be the top priority for a lab and they don't have it. Next, ask around. Ask your photography friends. Find out about their services. Can they push C41? The local lab I use can't so I have to send that stuff to my out of town lab. I stay at the local for everything else because their quality control is excellent. Sometimes you may use multiple labs because some are better at some things and others at other things.

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March 17, 2001

One way of doing that is to use slides, true, but slides are very inconvenient, especially since I don't have a slide scanner.

I am going to use Fuji NPH and Reala, because I trust those films. I will then ask the lab to print neutral density and colour balance so that they are not correcting my mistakes. This is going to be as close as I get to slide film for a while :)

Thanks for your input on this.

Ken.

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March 19, 2001

a. The Fuji Reala you have:
Has very, very fine grain. However, the color response is a little saturated. An alternative choice is Kodak's Royal Gold 100 (not to be confused with Gold 100).

b. Kodak Portra 160NC
Has very neutral color response, it's not saturated, and superb flesh and mid-tone. This stuff should match a color chart closely. It's not quite as fine grained as Reala, but close, and I would be tempted to use just this. However you already have the Reala. It's used by wedding photogs for the skin tones and that accurate prints from it _will_ match the color of the bridesmaids dresses! You could use just the Reala, but recognize it may be slightly more saturated than what you get from the Ektachrome. A Fuji alternative should be NPS 160; NPH 400 or Portra 400 NC would have a very neutral color response but with a noticeable increase in grain.

c. Kodak EPN-100:
This Ektachrome transparency has a very, very fine grain and very neutral color response, not saturated. Probably the closest E-6 to Portra NC. This stuff is made for catalog type work with daylight color temperature lighting. A Fuji alternative is Astia.

Procedure:
Shoot your test targets with all three films using the same lens(es), lighting conditions, distances and focus settings. Use equivalent exposure settings. Examine the prints from the Reala for resolution and Portra (or perhaps the NPS) for color balance. Compare these with the EPN-100 slides using a loupe. If you don't have a light table, use a white card (reverse side of a gray card) outdoors in bright daylight as a background to reflect the light through the slide. Even several pieces of white copier paper (stacked) can be used.

[Note: If you don't have an 8X or 10X loupe, you can use a fast 50mm standard lens (f/1.8 or faster) looking through it backwards, aperture wide open. Put your eye almost up to the front element and hold the slide about an inch or so behind the rear element. You will have to move the slide forward and back a little to find the "sweet spot" of critical focus; you'll know it when you find it! This is an old trick; older than dirt. Be careful with your lens doing it, especially with the rear element.]

Rationale:
You need some kind of baseline to compare the lab prints with that does not have any focus or color temperature confounded with what the lab's enlarger focusing and color balancing. The procedure makes an assumption that you can replicate lighting, proper exposure and focus for all three films closely enough that it doesn't visibly affect the results. I encourage you to shoot a roll of transparency with this test so if there is any question about the lab fouling up a print you can look at the slides. I test lenses and camera bodies only with the finest grained transparency films.

Hope this helps,
-- John

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March 19, 2001

Definitely a help! I am going to run half the roll inside with a flash, the other half outside with sunlight.

I have planned a few hours this weekend to take care of this project. If the differences in lab quality are noticeable, I might scan them in and post them here for anyone's interest.

Incidentally, I tried a new lab in my area who are a little expensive ($16.95 for a 36) but the photos I got back were immaculate.

Thanks again,

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March 21, 2001

Should have sent the film to the pro lab in the "Big City" about 60 miles away, but I wanted the low cost CD scans I could get with the consumer processing for a special web page. The unsettling thing is they have more rolls of Portra put in a couple days after the first one and I'm wondering now if I'll have to reject them too.

The event was a reception, one of the few types for which I use color negative. The prints need to be delivered to a relative for a "Memory Book" and I agreed to make a web gallery from selected photos. At least the CD was acceptable (I can rework its color balancing). It reminded me once again why I switched to transparency for all but a few tasks, and why I usually ship color negative to a distant pro lab. It costs about twice as much for a single set of 4x6 from 36 exp., about $17 plus shipping, but they consistently deliver very high quality. After a while the extra cost is worth the pain of frequently sending everything back for rework.

Guess I'm venting some about having to reject the prints last night. I would be very interested in the results of your test!

-- John

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March 22, 2001