Thorny problem I can’t solve.

[Mark Sloane]

I went to the lab last night to develop some film and I got my first good negatives in 4x5. I’ve been using LF for about 6 mos and always end up with under exposed negatives.

My first ones were simply transparent. Then I added a stop, (slower shutter speed), and started to get some detail.

I am now finally at 4 stops slower than my meter calls for and I finally have a decent negative. The lab tech last night confirmed that the negs were excellent.

The six negatives I developed last night; 4 were taken with a 150mm and 2 were taken with a 210mm with identical results. Sooooooo…….it must be the meter right?

I taped my grey card to the wall and put my 2 x d200s and F5 on spot meter, used an 85mm prime, set my A to 4.5 and had the following results:

D200 A: 1/2.5
D200 B: 1/2.5
F5: 1/2
Spotmeter: 1/2 w/A at 4.05

The Minolta Spotmeter M does not show a 4.5 for A on it’s digital display.

I’m using TMAX 100 Readyloads so that might be a stop. Some folks have tested TMAX 100 to really be closer to ASA 50.

I shoot landscape and my focus is usually around infinity so I don’t have a bellows calc to worry about.

All my negs were exposed at 8 seconds or less.

Before I send my gear to skgrimes I wanted to see if anyone here could help. I know it has to be me (operator error) but I’m lost.

[Glenn Thoreson]

I'm confused. You say your negs were exposed at 8 seconds or less, what kind of light were you shooting in? Were you using filters? Were you shooting at 4.5? 8 seconds at 4.5 should give you detail of some kind, even if you were shooting the inside of a black cat in a coal mine.

[Mark Sloane]

I'm confused. You say your negs were exposed at 8 seconds or less, what kind of light were you shooting in? Were you using filters? Were you shooting at 4.5? 8 seconds at 4.5 should give you detail of some kind, even if you were shooting the inside of a black cat in a coal mine.

Sorry for the confusion.

An Image of a barn was exposed at f32 @ 4 sec and the bracket at f32 at 8 sec with a red filter with a filter factor of 5.

Spotmeter readings were low ev at 11 and high ev was 16.3. I wanted my middle grey closer to the lower ev so I averaged out at an ev of 13.

ev 13 with f32 = 1/8. Add 3 stops = 1s. Add 2.3 stops for filter factor 5 = 4s. Add 1 stop for bracket = 8s.

[BarryS]

Mark--tell us how you use the spot meter. Maybe you're having issues with the type of tones you're measuring (the highlights?). Do you know the sunny 16 rule (f/16 at the reciprocal of the film speed, e.g. 1/60 for TMAX100 under sunny conditions. Do you need to expose at 1/4 @ f/16 in the sun? I'd also wonder about the lab. Have you tried taking duplicate shots and splitting between labs? Four stops off is a *lot*, so you may have more than one issue at play. Seriously consider developing your own negatives for the cost and control reasons.

[BradS]

OK..

I'll assume that you have all of the light meters set to the same film speed - let's say, ASA 100.

then, the F5 is telling you that it reads f/4.5 , 1/2 sec with ISO 100 speed film...right? That means that the light is something like: 4.333 + 1 = 5.33 EV...not much light.

Now, you're saying that the Minota spot meter reads the exact same scene as: f/4, 1/2 sec - right? That's only 1/3 stop different from what the Nikon says - right? Am I understanding this correctly?

I am not familiar with the minolta spot meter but, either you don't have both the meter and the nikon set to the same film speed or...you're transferring th exposure data to your shutter wrong or...the shutter needs a serious going over...or, you don't really have TMAX 100 in those film holders....or, perhaps, you've loaded the film 'emulsion side down'?

[Mark Sloane]

Mark--tell us how you use the spot meter. Maybe you're having issues with the type of tones you're measuring (the highlights?). Do you know the sunny 16 rule (f/16 at the reciprocal of the film speed, e.g. 1/60 for TMAX100 under sunny conditions. Do you need to expose at 1/4 @ f/16 in the sun? I'd also wonder about the lab. Have you tried taking duplicate shots at splitting between labs? Four stops off is a *lot*, so you may have more than one issue at play. Seriously consider developing your own negatives for the cost and control reasons.

Barry,

I do develop my own film. Our lab tech at the darkroom is a very accomplished photographer and I always run my negs by him for analysis.

I use the spot meter by finding the highest ev value in the composition and the lowest. I write these down and then look for a middle grey. If I have time I pull my grey card as well. A little artistic lic to determine where my average should be as long as it's within 6 ev from high to low. On my clipboard is a form where I write the details of the exposure down. My form also has a place for filters and the filter factors so I know evactly how many stops to adjust. Just below the form is my ev table for iso 100.

Do you think I should expose some film according to the "sunny 16 rule"? I could try that. Shoot three at different speeds with each lens?

[ic-racer]

Finding your IE can be done by trial-and-error, as you are doing, and there is nothing wrong with that. Alternatively you can expose some negatives of a zone I target at varying exposure indexes (using your preferred meter) The frame producing a 0.1 log density would correspond to an acceptable exposure index for that lens/shutter/film/exposure meter combination.

[Mark Sloane]

OK..

I'll assume that you have all of the light meters set to the same film speed - let's say, ASA 100.

then, the F5 is telling you that it reads f/4.5 , 1/2 sec with ISO 100 speed film...right? That means that the light is something like: 4.333 + 1 = 5.33 EV...not much light.

Now, you're saying that the Minota spot meter reads the exact same scene as: f/4, 1/2 sec - right? That's only 1/3 stop different from what the Nikon says - right? Am I understanding this correctly?

I am not familiar with the minolta spot meter but, either you don't have both the meter and the nikon set to the same film speed or...you're transferring th exposure data to your shutter wrong or...the shutter needs a serious going over...or, you don't really have TMAX 100 in those film holders....or, perhaps, you've loaded the film 'emulsion side down'?

yes your correct on the metering. All 4, 2 x d200, the F5 and the spotmeter where within a 1/2 of a stop.

I don't load my own film. I use Kodak T-MAX 100 readyloads and I load them in the holder correctly.

[BradS]

yes your correct on the metering. All 4, 2 x d200, the F5 and the spotmeter where within a 1/2 of a stop.

I don't load my own film. I use Kodak T-MAX 100 readyloads and I load them in the holder correctly.

perhaps, applying a filter factor in the wrong direction? (I have to admit, I'm just grasping a the wind here).

[Mark Sloane]

The frame producing a 0.1 log density would correspond to an acceptable exposure index for that lens/shutter/film/exposure meter combination.

ic,

I'm reading between the lines here a little perhaps but are you suggesting that each combination of lens/shutter/film should have it's own EI with the same meter?

I would have hoped that with the shutters on all my lenses properly calibrated that I would have a uniform platform if I used the same film and meter.