Color Transparency Exposure

[Bob Phipps]

Hi, As a beginner to 4X5, I have tried B/W [Agfa APX]and color transparency {Fugi Velvia & Velvia 100F and E100VS]. My Sekonic 508 is used for exposure readings. The B/W exposure seems to come out okay, but color trans. is terrible. Generally under exposed. What am I missing? I meter for the high lights as I would in 35mm and 120. I have dropped from f45 back to f32 or f22 and still get under exposure. Perplexed. Bob

[Edward (Halifax,NS)]

When you figure it out, let me know too.

[Matt Miller]

Maybe your shutter is slow. It could be & you just don't notice it in the B&W negs.

[Edward (Halifax,NS)]

Matt, if that were the case it would be because I am counting too fast (which is possible) because most of my exposures are in the 2-30 second range. And no, it is not reciprocity. I am using the 100F line of Fuji films.

[donald johnson]

I agree with Matt. I bought a shutter tester from Calumet, and 5 out of my 6 lenses were slow, sometimes by as much as more than a full stop, at the highest (1/125 and up) settings. Curiously, the slow speeds, which everyone is always concerned about, were all within 1/3 stop.

[Gem Singer]

Hi Bob,

If your shutter is too slow, your trannies will be over-exposed. It's possible, but not very probable, that your shutter is too fast, leading to the under-exposure you are experiencing. Simply changing the aperature won't solve the problem unless you also slow down the shutter speed. You probably are rating the speed of your color transparency film too high. Try rating it at a lower speed.

Try spot metering on an 18% gray card, or a middle gray area, instead of the highlights. Then, check the brightness range to make sure it isn't too high for transparency film. Jack Dykinga gives a clear description of this metering procedure in his book "Large Format Nature Photography".

[Dan Fromm]

Eugene has the answer, if not the analysis. If you meter the highlights with a spot meter it will pick an exposure that puts them at mid-grey. Then everything darker will come out, well, darker. That's nearly everything else in the frame.

That your meter wants f/45 may be a tipoff that something's wrong. At what shutter speed does it want f/45 with your ISO 100 films? Come to think of it, what shutter speed are you using at f/22? If faster than 1/50 (right to one stop under as implied by sunny 16 in normal lighting out-and-about) you're almost certainly guaranteed dense transparencies.

It is also possible, as he suggested, that you inadvertently misled your meter by setting a speed higher than the film's speed. I sometimes do that with my main meter, find the mistake when checking with the backup or when the main's recommendations seem, um, out of line with conditions. Its always painful.

Incident metering doesn't always give the right answer, but by george it yields consistent results.

Cheers,

Dan

[Danny Burk]

Are you getting satisfactory results with smaller formats? If so, try shooting a test subject on 35mm or 120 at a certain aperture/speed (say f/22 at 1/30 or whatever suitable exposure may be at the moment), and shoot the same settings with the same film on 4x5. You should get equivalent results unless your LF shutter speed is off.

[Kirk Gittings]

I recently was in the market for a new meter because I dropped my Pentax Digital Spot. I was also thinking of getting a newer design. I tried a few of the Sekonic models (4 newish or brand new) which were available thru a friend of mine who was reviewing them and the local camera store. Everyone of them overestimated the light levels by 2/3 to a full stop on the spot meter setting, which would result in over exposure unless you had determined a personal EV. These were mesured against a borrowed Pentax Digital Spot Zone VI Modified that had been recently calibrated by Calumet.

This seems very odd and I can't explain it. Jorge has suggested that the spot meter on the Sekonics is calibrated to 12% grey rather than 18%?

The net result is that I bought the Zone VI modified and sent my broken one in to Calumet to be repaired and modified.

[Andrew_3677]

I have a similiar problem when shooting color transparencies with my 8x10 (i shoot BW 95% of the time). My BW shots i meter with a spot meter and use the zone system and they seem to come out pretty well. When i shoot 8x10 transparencies they are almost always way too dark, so for transparencies that would be over-exposed would'nt it?