My exposures are way off from what one would expect

[snark]

Here's another dumb question. I hate to sound like a noob - I've run thousands of rolls of film through various cameras in the past fifty years - but I have a problem I cannot noodle through without some help. I have long wanted some nice equipment I never could afford before, and recently I got bargain prices on an RB-67 and a Mamiya C-3 TLR, both with prime (80/90mm) lenses and 180mm lenses. I have a Gossen Lunasix light meter. I ran a couple rolls of Arista EDU Premium 400 through both cameras following the incident light readings under various light conditions and the negs from both cameras came out very thin. I then exposed a roll to check the shutter speeds - bright sun, 1/125 at f8, 250 at 11, etc. and they all came out pretty close, so I figure the shutter speeds are okay but the negatives were still very thin. I did it again and changed developers. Same results. I then shot one more roll and played with the exposures. Consistently I got good exposures when they should have been way overexposed (bright sun, 400 ISO, 1/500 at f5.6 gave me a good negative). I did this with all four lenses (90mm and 180mm with the RB67 and 80mm and 180mm with the C-3) and all were acceptable negatives when similarly overexposed. This makes no sense to me. With ISO400 film I have to use an exposure index of 100 to get an acceptable negative. It's hard to believe the shutters in all four lenses are uniformly inaccurate to this degree. I am meticulous about my darkroom work -time and temps, contamination, etc, so that is not a factor. I used Arista Premium developer 1:1 for the first couple rolls and Microdol 1+3 (the only other developer I had on hand) for the last one. Any suggestions?

 

[Derrel]

Incident light metering is great for getting a highlight placement exposure, especially with slide film. But...that doesn't really meter the shadows, or tell you much about the scene brightness range.

I read and re-read your one gigantic paragraph several times. What I can decipher is that the light meter you have, used the way you are using it, needs to have 2 full EV value added to the Exposure Index that gives decent negatives, with your meter, your metering, and your film with your development.

Trouble-shooting a problem can be tricky; if you have left out something, or overlooked a setting, solutions offered might not be "right". What I would say though is that the light meter, as calibrated, as it is being used (incident, pointed who knows where...at the light or at the camera???) is NOT GETTING THE RESULTS you expect or desire--with your film, your water,your thermometer, etc.

But,on the other hand, the supposedly "over-exposed film" coming out okay...if the film really *was* an ISO 400 film stock (mis-loaded film is a possibility,perhaps, cannot be totally discounted), the very generous over-exposure of f/5.6 at 1/500 in full,bright sun makes me wonder about your darkroom aspects; maybe the water supply has been treated with a summer-time algae-inhibition agent which has altered the pH of the water? Or, maybe the thermometer you use has gotten out of calibration?

Is any of this making sense?

 

[limr]

I also thought of the possibility of mislabeled film. Arista is just repackaged Tri-X or Plus-X, no? Or it least it has been. Freestyle has been known to change its suppliers. I had a batch of 120 Arista that was repackaged Shanghai before they switched to Fomapan.

Could the shutter or aperture settings in the camera be off? Where did the cameras come from and how much do you trust that they're clean and tested?

 

[snark]

Thanks, Darre1 & Lenore. I should have left the light meter part out. I've never really trusted the thing, and don't use it except in unusual situations that I'm not comfortable using my calibrated eyeball. The "sunny 16" technique works well enough for me for "normal" photos. In bright sunlight with ISO400 one should expect a decent negative at f16. End of story.

I sincerely doubt my darkroom procedures are influencing this; I am being scrupulously careful in order to eliminate that possibility, using both analog and digital thermometers to stay within +/- 1 of 68F. Can the public water supply affect developers enough to cause this? Never heard of that. I've processed B&W film all over the world with local water and never have noticed a difference.
I also considered quality control over the Arista film. I left this out because of the length of my original post, but I sacrificed an expired roll of Plus X in this experiment as well, and it also turned out thin.

The RB-67 and 180mm lens came from a studio. It was well cared for, but for decades probably has only been used with flash. The 90mm lens was off Ebay. Looks like it was used by an instructor.

The C-3 TLR and 180mm lens came from a local amateur like me who shut down his darkroom and sold me his cameras. The 80mm came from Ebay and I had to clean the shutter mechanism before it would fire. So they came from diverse sources, and although I am sure they all could have problems I would be greatly surprised at them all having the same problem.

Thorny issue, not? As you folks apparently are, I am becoming convinced that the lenses are indeed all similarly dysfunctional. They are all Mamiya-Sekor shutter mechanisms and all about the same age, so maybe that is not as far-fetched as I thought.

Any other suggestions?

 

[Derrel]

I do not suspect the lenses at all. Not even a little bit. Especially if the same issue exists in a TLR and an SLR.

The common issues seems to be from my reading 1) the light meter or 2) the film stock or 3) the developing process. The two cameras and multiple lenses are cross-checks that show "something" is wrong. The fact that a simple 2 EI adjustment to metering/exposure givers good negatives indicates the developer stage, to me, more than anything else.

Two different cameras, producing very thin negatives. Leaf shutters typically get old and start to run very SLOW...a shutter in an old Mamiya that ran "too fast" at 1/50 or 1/60 second would be very rare. Speeds of 1/50 to 1/60 are, according to Marty Forscher, typically the closest to accurate over cameras of many decades' vintage...and as we all know, slow speeds like 1 or 1/2 to 1/10 on many older disused leaf shutters are often very sloooooooow if the mechanism is gummy.

Using two thermometers helps: many old-style analog steel dial and probe thermos get "off"; I have measured 5 degrees Farenheit in four different old dial thermos we used to have in one lab vs a Kodak process thermometer....that's a "LOT" of variation.

I think there's a fundamental issue. I still suspect the developing process. Especially when you say that a 2-astop OVER-exposure results in good negatives. Sounds to me like your development is simply too short; or the developer is too weak; OR the developer is not giving the true emulsion speed the film ought to have, when paired with the developer you are using. How solid is the developing time you consider normal? Has that time and dilution been "PROVEN" over much time and film?

There are a lot of variables, but I keep coming back to the fact that a 2-stop EI adjustment is "fine". In recent times, there have been some pretty "weird" development times suggested in "official" documents...osme times that just seem ridiculously short to me, based on my own experience with older formulations of say, HC-110. hat's why I asked about the reliablility/proven time of your development time.

You say the negatives are "thin". Maybe the development is simply not long enough, or the film does not realize its full emulsion speed with the current developing routine.

 

[compur]

Your Gossen Lunasix meter uses mercury cells which are no longer sold in the USA. If you are using alkaline "equivalent" batteries in your meter the difference in the voltage between mercury (1.35v) and alkaline (1.5v) could account for the 2 stop error in exposures as I reported in this thread:

http://www.thephotoforum.com/forum/...789-mercury-vs-alkaline-batteries-om-1-a.html

 

[snark]

Yep, yes, and uh huh. I could not agree more. The odds against all these shutters being similarly fast - not slow, as you point out - make winning the lottery seem like a safe retirement plan in comparison. I am recently retired and just getting back in to photography after a long hiatus, so I really don't have any track record with the film and chemicals I am currently using (the stuff I used to use is hard to find and real expensive now, so I am starting over with the Freestyle products). That's why I changed to Microdol in my last experiment today, to try to nail down whether it in fact is a developer issue. I am going to start playing with the developing times rather than the exposure times.

Good advice. Thanks so much for the second opinion.

 

[snark]

Compur, I just read your post about the batteries. Gadzooks. I was getting some weird meter readings - not all the time but often enough to make me suspect something was bad wrong. That's why I put the meter back in the drawer and relied on experience. Incredible. Thanks to you, the Lunasix will stay in the gadget bag . Is there a reasonably priced, dependable meter you would recommend?

 

[Derrel]

Here's a good example of what I consider to be wonky "OFF" official development time suggestions, direct from Kodak:

http://www.kodak.com/global/en/professional/support/techPubs/j24/j24.pdf

HC-110 Dilution B at 68 degrees only 5 minutes? In my experience, that time is way too brief for either Plus-X or Tri-X. Just. Way. Too.Brief.

Unless HC-110 has been re-formulated and made ridiculously strong, that "official" developing time is about 2 minutes too brief, based on thousands and thousands of rolls of Tri-X I have personally developed from both myself, and from multiple newspaper shooters.

 

[snark]

Yes. I am similarly suspect of some development times in the Freestyle chart. Why would Arista Premium powder be 8 minutes stock solution and only 8.5 minutes 1:1? I have been using the 1:1 formula.

Do you think my water softener could have an effect? That is a variable I have never dealt with before. It's a traditional outfit that works with salt pellets.

 

[Derrel]

Yes. I am similarly suspect of some development times in the Freestyle chart. Why would Arista Premium powder be 8 minutes stock solution and only 8.5 minutes 1:1? I have been using the 1:1 formula.

Do you think my water softener could have an effect? That is a variable I have never dealt with before. It's a traditional outfit that works with salt pellets.

I have no experience with Arista's developer...but 8 minutes suggested at full strength, but only 8 min 30 sec when diluted 1:1 with water?? Huh??? That just seems...wrong, no?

As I alluded to above when I put forth the possibility that, "maybe the water supply has been treated with a summer-time algae-inhibition agent which has altered the pH of the water?"...ummm...yeah...I suspect that the salt that your water softener uses might affect the developer solution.Chemistry is a weak subject for me. I have no idea what the formulation of the Arista developer is.

I suppose you could, and probably would find it interesting, to mix up some developer using a jug of distilled water bought from a store...

I really wanna' know how this all shakes out for you!!!

 

[snark]

I am traveling next week so I guess it will be a week or two before i get back into the darkroom. When I do, I will post again. I am confident I will work through this with the insight given in this thread. Again, thanks all.

 

[compur]

Compur, I just read your post about the batteries. Gadzooks. I was getting some weird meter readings - not all the time but often enough to make me suspect something was bad wrong. That's why I put the meter back in the drawer and relied on experience. Incredible. Thanks to you, the Lunasix will stay in the gadget bag . Is there a reasonably priced, dependable meter you would recommend?

For ambient light I like this little meter from Sekonic. It is accurate, fits in a pocket and has low cost:
Sekonic Light Meter: L-208 TwinMate Exposure Meter - Overview

 

[vintagesnaps]

I learned to develop film but haven't in a long time; was using a shared darkroom at a university (with time constraints would get the film developed, look thru my negs ahead of time then use their enlarger & darkroom to do my own prints). But I'd wonder about it being the chemistry, especially if you've already tried more than one. Would it work to try bottled instead of tap water? Or maybe try sending a roll out to be developed and see if a lab would get the same thin negs using their chemistry and equipment?

Usually if I've gotten a thin negative it was because I didn't get a decent exposure. I wonder if it's the meter readings... I've found that some of the batteries made for older mechanical cameras don't always seem to last too long so that could be the problem with the meter. I wouldn't think you'd get the same results with different lenses, and my best semi-educated guess would be that the exposure is off, whether from the meter or the camera malfunctioning.

Maybe go out shooting and take along another camera to compare (same time & place, scene/subject, lighting etc.), take notes and compare results. If you get different meter readings from two different cameras/meters in otherwise the same conditions, then I'd think it was the meter; if you use the same settings and get thin negs from this camera then I'd think something was wrong with the camera, that the shutter speeds are off or something else is wrong with the way the camera is exposing the film.

 

[snark]

Hi, Sharon. There are a lot of variables, aren't there? I think I have a combination of all the possibilities you and the others have mentioned, and I need to methodically isolate and eliminate the problems. Your suggestion that I send a roll off to a lab is just more evidence of my advancing age and muddled thought processes - why the heck didn't I do that already? That's the best way to eliminate the darkroom as a factor. Thanks for mentioning it - I will send off a roll in tomorrow's mail and see what comes of it. And I'll definitely try distilled water for mixing developer in the future. A buck a gallon is cheap insurance.