AutoExposure Tips thread...

[Juan Valdenebro]

Hi everyone,

I thought it would be nice to have a thread for AE tips... For years my favorite tip about it, was “don't use it”... But I've been using AE for some time now, trying to make it reliable and fast...

So, I'll begin with the first tip...

When I expose a film for all the light it can take (say Tri-X at 250), using AE is a breeze, because any “normal” exposure error will produce a negative that's yet totally inside film's latitude, and you'll be able to print or scan for great shadows and highlights...

But when I use AE for pushing, I can get, after the same amounts of “normal” exposure errors, negatives grossly underexposed or overexposed, especially underexposed ones... I checked a few frames I shot two ways each: first with incident metering (400@1600), and then AE... On most of them I defined the center of my frame identically: half that center was a gray card (left), and the other half (right) was a B&W photograph with a 3 inch white border... All images were perfect when incident metering was used (film ISO/development for soft light was previously calibrated) but the identical image with AE was really underexposed (every time): I would have imagined the difference was going to be really small, as my camera meters considering the center a 60%... But the difference was huge... None of the shots were under direct light, all were overcast or interiors' ambient light shots, so if the underexposure can be that wild with white paper, I don't even want to imagine what happens with sources of light!

So, the tip is, use AE differently -caring a lot, finding a middle value anywhere- when you really push.

It sounds almost stupid, but for that kind of push the tonal range is really reduced, so you already lost your shadow detail: if apart from that you underexpose 1 stop or more, you get nothing!

Cheers,

Juan

 

[Juan Valdenebro]

Another one, but related to the previous one:

For AE & pushing, I prefer to have my camera set to +1... If I have time to meter well, I'll use incident or at least camera's meter, and decide depending on the metered area... But for being ready to act quickly or to snap in several directions avoiding metering, +1 has been to me better than N... I guess one of the reasons is white walls are common, as light sources (lamps, windows, overcast sky...) and in case the metered area was medium, shooting at +1 is no problem: very high values will be white, but no more problem: that's OK even for skin... But if I use AE at N, I can easily get underexposure: -1 and -2 happen easily... That's a wasted photograph most of the times... And it can be worse than -2!

Cheers,

Juan

 

[Roger Hicks]

Hi everyone,

I thought it would be nice to have a thread for AE tips... For years my favorite tip about it, was “don't use it”... But I've been using AE for some time now, trying to make it reliable and fast...

So, I'll begin with the first tip...

When I expose a film for all the light it can take (say Tri-X at 250), using AE is a breeze, because any “normal” exposure error will produce a negative that's yet totally inside film's latitude, and you'll be able to print or scan for great shadows and highlights...

But when I use AE for pushing, I can get, after the same amounts of “normal” exposure errors, negatives grossly underexposed or overexposed, especially underexposed ones... I checked a few frames I shot two ways each: first with incident metering (400@1600), and then AE... On most of them I defined the center of my frame identically: half that center was a gray card (left), and the other half (right) was a B&W photograph with a 3 inch white border... All images were perfect when incident metering was used (film ISO/development for soft light was previously calibrated) but the identical image with AE was really underexposed (every time): I would have imagined the difference was going to be really small, as my camera meters considering the center a 60%... But the difference was huge... None of the shots were under direct light, all were overcast or interiors' ambient light shots, so if the underexposure can be that wild with white paper, I don't even want to imagine what happens with sources of light!

So, the tip is, use AE differently -caring a lot, finding a middle value anywhere- when you really push.

It sounds almost stupid, but for that kind of push the tonal range is really reduced, so you already lost your shadow detail: if apart from that you underexpose 1 stop or more, you get nothing!

Cheers,

Juan

Dear Juan,

Seconded. And if you must use it, remember that while a stop or two of overexposure matters very little, even half a stop under can lose important shadow detail.

Set one-half or even one-quarter of the ISO speed on your meter. If the former, favour (point the meter at) the 'shadows' (worse lit areas) when metering; lock the AE. and it'll be quite difficult to get an unprintable negative.

Of course overexposure reduces sharpness, but it's often easier to live with this than with inadequate exposure.

For pushing.... well, go for 1/4 EI AND favour the shadows. Or shoot at the widest aperture you dare, for the longest shutter speed you dare...

Cheers,

R.

 

[CorreCaminos]

This is not really a tip but rather my personal approach to AE; perhaps it'll help others find AE more useful as it did for me.

I used to think I had no use for it but that changed a few days ago when I realized there was a different way to think about it and what it does.

I have, or have had, several cameras with AE (Nikon FE2, F3HP, and Leica R9) but never really used it as I didn't like the uncertainty of not knowing exactly which area was being metered or how the meter would interpret tricky lighting situations. This, to me, made the AE program unreliable and there was no point in switching to AE; I might as well meter manually or use the sunny 16 rule.

But it recently occurred to me that I was thinking about it all wrong. Perhaps AE was never meant to be used as a fully auto feature but rather as a convenient way to speed up exposure under most normal conditions. This is a very subtle change on my thinking about AE but it makes all the difference for me. I now use AE to automate a rather rote and uninteresting task, namely match the aperture and shutter speeds, under circumstances that the meter can handle perfectly while watching for cases where the meter can be fooled.

The R9 makes adjusting the AE up or down incredibly easy with the AE compensation lever. The Nikons are harder to use as they require to take your eye off the viewfinder and turn the AE comp ring, but it's still worthwhile to use.

 

[Bob Michaels]

I think the key to using AE is to always look at the indicated AE reading and conclude if it makes sense. You should have a good idea what the exposure should be before you ever pick up the camera. It is very simple using sunny 16 or just remembering what works. If the AE reading makes sense, fire the shutter. If not, figure out why. Just don't believe you can ignore everything because the computer in the camera is smarter than you.

I am amazed that the people who post they they have mis-exposed their film by 4 stops. You wonder if shooting Tri-X in direct sun f4 @ 1/125th was not some tip off.

 

[Steve M.]

AE isn't a feature I'd want unless you have a convenient and fast way to lock the exposure. Many camera makers seem to have left this off, or made it very difficult to achieve. Other cameras, like the Nikon SLR's for example, are intuitive and require only that a little slide be pushed.

The best way for me to meter accurately and quickly is to have a camera w/ spot metering, AE, and AE lock. Simply find your subject of interest, lock exposure, focus, recompose, and shoot. This happens really fast, and you can't do it any more accurately any other way that I know of.

 

[pagpow]

I don't think that AE is very different from say, blindly following any meter, particularly through the lens.

My experience suggests that AE or match needle depends on the camera, the meter, the light level, and the film or light sensitive material.

For example, I started photography w the Canon FTb and F!, both of which had well defined metering areas identifiable in the VF. And the meter was not linear, but biased towards a bit of underexposure at low light levels. This gave me an extremely high hit rate without thinking. Nevertheless, when shooting Kodachrome, I would bias the film speed setting upward, "underexposing" some. And when it was dark outside, I would also "underexpose" from the indicated exposure if I did not want the scene too light.

On the other hand, with the more sophisticated metering of say a Canon S90, I generally bias the AE -2/3 and get very realistic exposures under a lot of conditions.

With my RD1, OTOH, I have to "underexpose my meter setting by one and sometime 2 stops if I do not want to end up capturing a night-time shot as daytime.

Subject departures from middle gray also required some thought -- but if dealing with the same conditions for a while, biasing the AE correctly then allowed very fast shooting.

Am I missing something?

Giorgio

 

[CorreCaminos]

I don't think that AE is very different from say, blindly following any meter, particularly through the lens.
Giorgio

This is how I used to think about AE and why I never bothered to use it until a few days ago. I now see it as a short-cut to a properly exposed photograph, but only under the lighting conditions the meter can handle. In my mind, I'm still using manual mode but, instead of turning the shutter dial myself, I let the camera suggest a shutter speed to match the aperture I selected.

What I do now is similar to what Bob mentions above; I know what exposure I want beforehand and compare that to the AE. If my exposure settings and the AE match, then it worked great and it saved one manual step (setting shutter speed to match my chosen aperture). If it doesn't match, I'll either switch to manual mode or use the AE compensation dial/lever until I get what I want.

I don't like using the exposure lock and much prefer a separate control for AE compensation.

 

[Austerby]

I've been a long-term user of AE, going back to my Nikon FE in the early 1980's (still going strong today) and more recently on my Zeiss Ikon and M8.

I've always found AE to produce perfectly acceptable photos provided you think about what you see and make adjustments as required, usually by removing a potential source of mis-reading from the view, applying the AE lock and then recomposing.

I'd rather use the AE lock than a compensation dial - one of the best cameras for this is the Leica M7 with the half-press of the shutter locking the exposure.

 

[charjohncarter]

I have different ways of shooting most of my 6 AE cameras. I like a lens hood which maybe rightly or wrongly helps narrow the field (at least, I think it does) so highlights from outside the frame don't distort the reading. But my Olympus Infinity Stylus can't have a hood and it seems to be on; always.

 

[Juan Valdenebro]

I was wondering... How do members compensate when -while shooting a direct sun roll- you need to shoot, in the same roll, one frame in the shades...? Or if doing a soft light roll, you need to include in that roll a sunny frame? Or if you always mix contrast scenes, how do you compensate their exposure to get the best results out of just one development time? Thanks!

Cheers,

Juan

 

[Bob Michaels]

I was wondering... How do members compensate when -while shooting a direct sun roll- you need to shoot, in the same roll, one frame in the shades...? Or if doing a soft light roll, you need to include in that roll a sunny frame? Or if you always mix contrast scenes, how do you compensate their exposure to get the best results out of just one development time? Thanks!

Cheers,

Juan

Juan: I know you use different cameras, different films for different lighting situations. I can not. I always have mixed lighting on each roll. Frequently I will return with 20-25 rolls of exposed film containing lighting that varies from flat dim indoors to bright direct sun with harsh shadows outdoors. So I must process everything the same. I rely on the latitude of the film to cover everything.

I try to give consideration to the contrast of the lighting when determining exposure. That way I am not using up some of the film's exposure latitude to compensate for bad metering / exposure decisions.

When the lighting is flat and dim, I give a bit of extra exposure if I have it available. Sometimes I am already shooting with the lens wide open and as slow a shutter speed as I can hand hold so just cannot give extra exposure.

I would love to have normal negatives to work with but must accept that is not always possible. Then I do the best with what I have.

 

[Juan Valdenebro]

Hi Bob,

Thanks for your answer! I didn't see it back then...

Well, I did that too for many years... I just don't know how good it is for wet printing because I started developing for the scene's contrast before I started wet printing...

But sometimes, while shooting a sunny roll, It's happened to me that while hitting the shutter, a cloud was just starting to make light dimmer... Even if in those situations I've been using an AE camera, when I check those negatives I see those lower contrast frames are very flat (as I pull sunny scenes) AND they're really far from reaching whites... So I guess the only solution for "urgent" flat light shots inside sunny rolls is bumping exposure... With a sunny roll as I do them (pulled) I'd say I should shoot (keeping ISO) at +2... Maybe doing it regularly for mixed scenes (not pulling) would require less compensation... I thought lots of RFF members used to shoot this way: mixing scenes and compensating... I wanted to hear about some personal "systems" for that...

Cheers,

Juan

 

[bwcolor]

Funny, this thread ignores slide film. I'm guessing that positive films are pretty much DOA. I do a lot of AE off my palm with +1 exposure compensation set on camera. Also, meter off the sky and "Mr Green Jeans". If I get even more mindless in my efforts, I just reduce the EI.

 

[Keith]

Funny, this thread ignores slide film. I'm guessing that positive films are pretty much DOA. I do a lot of AE off my palm with +1 exposure compensation set on camera. Also, meter off the sky and "Mr Green Jeans". If I get even more mindless in my efforts, I just reduce the EI.

And judging by this quote from Roger we're certainly not considering digital here either!

Seconded. And if you must use it, remember that while a stop or two of overexposure matters very little, even half a stop under can lose important shadow detail.

A stop or two of overexposure with digital and you may as well press the delete button because you're not going to salvage anything from the highlights.