Newbie Question: Neg vs. Transparency Exposure...

[cleeo_w._wright1]

I've been doing the LF thing for a little while now with an ancient 4x5 and I'm having a blast. I've gottoen to the point where I am pretty confident when shooting color print or B&W but for some reason I'm missing the exposure big time when it comes to chromes. Sometimes as much as 4 stops. I'm really confused as I think that I'm doing things pretty much the same way. With the negative film I am not requiring any special processing. It comes out pretty good on the first pass even though I take duplicates just in case. My chromes on the other hand are awfulllllll..... Any advice would be greatly appreciated.

[john_whitman]

Expose for the highlights (by using an incident meter in the brightest

area of the scene).

 

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In which direction are you off by "as much as 4 stops," underexposure

or overexposure? Most people, when moving from b&w or color neg to

chromes, are in the habit of giving more exposure "when in doubt,"

which usually results in disastrous overexposure with chromes.

 

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...............

[cleeo_w._wright1]

Sorry... I should have mentioned that they were all underexposed. I

should also mention that I've been doing 35mm for quite a while and I

understand exposure pretty well. At least I thought I did. That is

why I am so confused. I'm really looking for any ideas on what I

might be missing or forgetting when it comes to the all manual

process. I'm using a Sekonic L508 for my meter. It is usually set

on incident mode.

[steve_baggett]

If your exposure times are greater than 1 second, this could be due

to a greater amount of reciprocity failure with chromes vs negs.

[stephen_ratzlaff]

Have you perhaps not calculated for bellows extension when making your

exposure determinations?

[mark_windom]

Cleo,

 

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You mention you're using an ancient 4X5. Are the lenses ancient as

well? To be off by 4 stops with the experience you have (I've seen

your work on the critique forum and it's quite good) I wonder if it

isn't an equipment problem rather than you personally. Is the

exposure problem occuring with all your lenses or just one in

particular? If it's only lens one you might want to have the shutter

speeds tested particularly if it's an old lens. A shutter speed

problem would certainly be much more noticeable with transparency

film vs. neg film due to the decreased exposure lattitude.

 

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Another suggestion would be to try a different metering method. I

occassionally use a spot meter but for most of my work I use the

meter in my 35mm. It's one more item to add weight to the backpack

but the results have always been very reliable.

[michael_feldman1]

Cleeo,

 

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Just to be sure, please describe in excruciating detail what the

transparencies look like that makes you think that there is an

exposure problem.

[edward_kang]

Cleeo,

 

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Yes, please describe in detail what you were taking a picture of, how

far away the subject was, time of day, type of slide film, etc. It

will help us help you =)

[dan_smith]

If you really are off by 4 stops with the chromes I doubt your

exposure is right with negative film. You are probably getting by

with the 'wrong exposure' and the ability of your printer to get at

least something out of the negative.

Even following the 'sunny 16 rule' and printed exposure charts for

indoor use you should be closer than what you say.

Check more carefully the negatives with a good pro lab to see just

where your exposure really lies and I bet it is close to the same as

your chromes... unless you are forgetting to change the film speed

setting on your light meter.

[jorge_gasteazoro]

If you are shooting Tri X (ASA 400) and then change to fuji Velvia

(ASA 50)that is about 3 stop difference, I vote for Dan's comment,

are you sure you are not forgetting to change the setting on your

light meter?

[pete_andrews]

"Expose for the highlights (by using an incident meter in the

brightest area of the scene). " - What?<br>An incident reading is a

measurement of the light falling (incident) on the subject. The

brightest area of the scene has nothing to do with it.<br>The subject

is assumed to be 'average' with the highlights falling 3 stops above,

and the shadows 4 stops below the nominal exposure point.<p>I'm not

disagreeing that an incident reading gives good results, especially

with transparency film, but the accepted method of use is to stand at

the subject position and take a reading with the meter cone or dome

pointed back at the camera. If the main subject is completely in the

shade, then so be it. You shouldn't go out of your way to find the

brightest patch of light to stand in to take an incident reading.

[steve_swinehart]

1. Have your shutters tested to make sure they are accurate.

 

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2. Make sure you have set the correct ISO speed on the meter.

 

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3. If you are doing closeups make sure you have applied the correct

belows factor.

 

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4. Learn to use the spot meter function on the meter and carefully

evaluate your scene or subject matter. Transparency film will

accomodate 5 stops with detail from the darkest area to the lightest

area. Things that fall outside of that range will be rendered as

totally black or totally white.

 

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5. Depending upon the transparency film used and how accurate you are

with your metering, you may get 6 plus stops instead of 5. Five is

safe, 6 is pushing the film in both directions.

 

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6. Depending upon the film you are using, if your exposures are over

1 second, you may be running into reciprocity problems. Check the

film data sheet to see at what exposure you have to apply a

reciprocity correction factor.

 

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7. When you've done all of the above - get back to use with the

results.

[bruce_wehman]

Cleeo,

Start with a known scene, for example: mid-day, bright sun and

subject matter with a variety of reflective values. Your exposure for

ISO 100 film should be 1/100 sec. @ F16. If your meter gives you

approx. this reading, the problem is probably not your meter or

technique. If, after shooting a sheet at these settings, you still

get 4 stops off, then your problem is lens/camera related....or maybe

a little of everything. But in any event this test should, at least,

help you zero in.

[bob_moulton]

Try this test. Expose a scene familiar to you--one you have shot

before. You say you have used 35mm. Ok. Put some Velvia, Ektachrome--

your choice of film--into your 35, same type of film into your

4x5.Set up both cameras on the same scene in same light. Meter the

scene the way you would with your 35mm. Expose a few frames in both

the 35 and the 4x5 using the slr meter. Now mater with the unit you

use for your 4x5. Shoot a few frames in both the 35 and the

4x5.Process all film.

If slr and 4x5 meter match exposure or are quite close, then it would

seem the problem is mechanical-shutter, aperture. It could be user-

not resetting your meter. It could also be chemical. You indicated

that your negative film exposures are fine. Others suggested that you

migth have forgotten to reset the exposure meter. I would also

suggest that when you exposure for negative film-b/w and color, you

expose for the shadows. With transparency film you expose for the

highlights. That may be a problem.

 

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Bob

[kcrisp]

Any chance this is an old lens with "US Stops" instead of what most

of use are used to?

[roger___3]

Cleo, I had a similar experience when starting LF. I have two

suggestions which may or may not help depending on your problems.

Have your shutter speeds checked (as already mentioned). My Ektar

203 was consistently off by one stop or more until it was

recalibrated. Cross check your light meter against an in camera

light meter from one of your other cameras in reflective mode. Mine

was off by a stop or more. I use incident metering when there is

even light (Gossen Luna Pro) and have found this method to pretty

consistently give good exposures on chromes. I assume you are using

your incident meter correctly, but if you have doubts you may want to

verify your technique.

[gwrhino]

Without seeing the film, it would be hard to judge what is wrong.

 

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An incident meter reads the light falling, not the amount reflected.

Very often the two do not coincide; ie the subject is not a nuetral

subject, reflecting an "average" amount of light. I learned this the

hard way. I was photographing the Javier Mission in Baja in dramatic

conditions. I'd been using the incident meter with good results for a

couple of weeks, and thought I might have my exposure problems

whipped. Turns out, the walls of the mission were so dark, that even

in bright sunlight I had underexposures.

 

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You will learn to judge which situations the incident reading will

work. In the meantime, get a spotmeter, calibrate it and trust it.

The reflected light reading is your bottom line.

 

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http://georgestocking.com

[philip_sweeney]

I really like the Kodak E100 line. its fine up to 10 seconds. with a

spotmeter place the brightest area (that you want detail in) in zone

VII. the transparency will be open and luminous in zones IV thru VII.