View Full Version : Experience of auto exposure?
I'm going to run a test roll on this myself, but just wondered if anyone has any experience of using the Auto mode?
I don't like the metering on the camera much as it is - can't work out if the sampling area is too small, or the weighting is wrong, or what, but I often get better results with guesswork. For example I was in a pub in Soho recently and couldn't get the camera to settle on a reading for the people sat opposite me (the indication arrows just kept flashing no matter where the shutter was set to) so in the end I took a guess, got the roll processed +.5, and ended up with a couple of nice shots.
So does the Auto function produce decent results? In a similar situation, is it going to get it right, or get it wrong?
Also, I've noticed that when the camera is on Auto, it sometimes choses shutter speeds that are not available via the dial - e.g. 1/350, or 1/90. This would seem to indicate that these settings are more accurate than the one that you would select if chosing manually - so in situations where the meter works happily (for example where the light is fairly uniform across the frame) would you get a (slightly) better exposure from the Auto setting than doing it manually?
Or am I just becoming ridiculously obsessive about accuracy... :D
The auto exposed shots I made are all pretty accurate. In my experience the only time it is difficult for the meter to make a decision when there is not enough light. When the exposure time would be more than 2 seconds. In manual mode it will measure for up to 4 second exposures. Anyway, in such conditions I always use guessimation and bracketing, or measure the light wide open and then stop down and compensate.
I am unsure about what camera you're talking about, but your comments could apply to my nikon fm3a and leica m7, both of which work really well in aperture-priority mode. Occasionally I do use the exposure-lock feature on the cameras to "select" exposure. You say you often get better results by guesswork. I would trust your non-battery-dependent judgment. In a way, our shooting is all practice for the one that turns out. To learn about the camera meter in different situations, what about exposing one frame according to the camera meter and a second frame according to your best guess? Just a thought.
The camera’s light meter (B&W for simplicity) wants to create an 18 percent (reflective) gray card world,
• point it at a black wall and it will result in a print showing an 18 percent gray wall
• Point it at a white wall and the resulting print will be an (18 percent) gray wall.
• Point the meter at an 18 percent gray card and the resulting print is an 18 percent gray print.
Most of us don’t carry an 18 percent gray card to meter off of, the 18 percent reflective standard was chosen because Caucasian skin is (about) 18 percent reflective.
Your dark pub in Soho might consist of dark shadows, bright highlights, perhaps bright point sources of lamps beaming into the lens. Want to use XPan on auto in such lighting? Tough lighting to meter.
Walk into the area you want to capture, become part of the subject read an 18% gray card or stick out your or another person’s hand and meter the hand so it fills the viewfinder, make mental note of the exposure e.g. 1/30 @ f 8. Now return to your desired vantage point from which you desire to photograph from. Meter the scene again, now adjust the exposure override ( - / +) until it auto meters 1/30 @ f 8. Your are metering with an adjusted auto meter. Color and B&W film and different developers each have their own metering requirements e.g. reading your hand in the shadows for B&W to preserve shadow detail.
This only applies to the scene and general conditions of the lighting, move to a different room in the pub or go out into sunlight and the corrections (-/+) no longer apply.
Easier to use the XPan on manual in such conditions, meter, set it - than step back and shoot.
Thanks, that's good advice, hadn't thought about it quite like that. And useful, given that I don't generally carry a grey scale to the pub!
I use the auto mode quite often for candid or hand held shots, with decent results. I just meter on the most important part of the scene, usually skin tones or mid tones, lock exposure by lightly depressing the shutter , recompose and shoot. This is a bit risky for slide film but is fine with b&w(in my limited experience!). If you have time a hand held meter is a good option, cheers. :)
Genen brought up a good point which led me into another question, its probably not directly related to xpan A mode but hope you guys can give me some enlightenment.....
the camera TTL metering will measure and make the photo look like a 18% grey, or zone 5. Say i am shooting some penguins in the south pole, do I always do the following?
1. use the reading that the camera gives and then add 2 stops to bring the photo back to zone 7 (to give the photo a true white snow instead of grey snow)
2. use a hand held ambient light meter and just use set the camera using the reading directly from the light meter.
are my assumptions above correct?
Had a Fuji TX1 for about 7 years and found the auto exposure pretty accurate throughout. Just point camera at mid tone, hold reading, recompose and shoot. Great camera..
My Fujica ST 901 with its Silicon Blue Cell (SBC) has always been quite accurate. It will measure down to about 30 seconds at f/1.4. Very useful.
However, no reflective meter will give you consistant results in difficult lighting situations. It will be fooled if there is a preponderance of light or dark areas in the scene. That is when experimentation and experience come to our aid. Cameras all have reflective meters unless you put an accessory dome on them, move to your subject's location, and use them as an incident meter.
Alice, generally incident meters give better readings in the situation you describe as they are doing just what their name implies, reading the light incident on the scene, not reflecting from it. However, you example is again an extreme. you would likely have to compensate. At http://www.butkus.org/chinon/luna-pro_sbc/luna-pro=3.htm you can read a short explanation of some of the differences and how a null meter can be of help. However, don't be discouraged if you don't have or don't want a null meter. Experience will allow you to do the same calculations for yourself.
And then there is always the possibility that your meter could be off up to 1 stop anyway. :bang: :p
EDIT: I don't know what has happened to the Butkus.org site. However, I notice this has become a busted link. Hopefully it will be back up soon for all those who manage to purchase a Luna Pro SBC and want to know how to use it. They are a really useful meter.
No problems with the A-mode, even with slides.
No gray card: measure a white surface and open the valve with 2,5 stops, or palm of your hand and 1stop
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