Exposure meter variation
I recently bought a Bronica SQA kit to wean myself off digital cameras. So far I've only shot in B&W, and I develop all my own film. I use a Sekonic 308 for metering, but I've found it consistently underexposes when compared to other metering methods (various Nikon SLR's). I know I can make a mental adjustment after taking a meter reading to compensate for the underexposure, but when I'm trying to sort out filter factors/metering shadow areas/contrast etc I get hopelessly confused and often miss the shot I want.
The question is - can I get a more reliable meter, or one that can be calibrated? Can non-digital meters be adjusted in any way? Can the Sekonic 308 be internally tweaked?
Ok, that's 4 questions. Sorry.
The first question is the 308 really having problems? It might be metering methods. If it is having problems you could send it in to be fixed. I've no idea who does that in the UK. The 358 has various adjustments. I assume the 308 has similar range of adjustments. But user adjustments are only good if the meter is always screwing up by the same amount.
I'm not sure what you mean by non-digital meters. The 308 is a digital meter.
I think it might help if you described how you're using the 308.
Meters can vary in their readings. If yours can be manually adjusted by some means, you can set it to agree with another meter that gives a consistent reading that you consider correct. If not, you'll have to adjust the ISO dial and make note of how "off" it is. Since it's consistently underexposing by the same amount, you can work around the inaccuracy.
Thanks for the replies. I'm using the 308 to take reflected light readings. I don't think there's any way to make adjustments on the meter (at least not without taking it apart).
When I said non-digital meters, I meant the needle pointer type (ie Weston Master). Sorry if that was confusing.
The differences may just be the field of view that the meters are seeing.
This will change with different focal length lenses on the slr.
Most older Nikons use a 60/40 combination where 60% of the reading is from the larger circle in the finder & 40% from the area outside it.
The sekonic sees only a fixed angle, so to get a more precise value, you may have to walk up to a subject to get an accurate reading.
Also if you are directing the Sekonic towards the sky it will influence the reading towards underexposure.
You don't have the incdent ball over the sensor do you? that would certainly affect readings too.
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I used an F4, F80, D70 and Fuji S2 to check the meter, all of which were in their 'matrix' metering modes (ie. not centre weighted or Spot). I chose not to use my partner's FE, as I was aware that the metering was centre weighted (although I didn't know the exact ratio - thanks for the info). I used the same lens for all tests (Nikon 50mm 1.8) to try and give the results some consistency. I assume that a 'standard' lens is the right one to use, as I would guess that the meter is tuned for a normal field of view.
However, this has got me thinking - there's no reason I can't use the D70 or S2 as a fancy light meter. It would be good to blow the dust off them once in a while, as they've not had much use since I got the Bronica
Thanks again for the help
IIRC, when you open up the battery compartment of the 308 (I had one some years ago so I forget exactly), there should be a little dial that you can set with an eyeglasses screwdriver to calibrate the meter. You would turn it one direction to adjust for underexposure, the other for overexposure.
When you say it consistently underexposes, by how much does it vary from the meter in your D70?
Make certain that you are orienting the meter in a purely vertical orientation, perpendicular to the ground, or at least parallel to your film plane. It is a great little meter and very easy to work with.
Sekonic has a web site and forum to discus problems you have, I am not sure if is Mamiya.com or Sekonic.com
Hope this helps
Looking is a gift, but seeing is power.
I believe you should compare the reading from your light meter with that of a known light meter. That will get the light meter out of the equation. The you should evaluate your metering techniques. Also make sure your camera (back) is set to the correct ISO, or is the back bad ? have you tried a differnt back and checked if the iso readings the camera back is transmitting is correct ? I got a soligor 1degree spotmeter and got it calibrated. you might want to borrow a light meter from a friend and try that. But I suspect that the ISO dial on your back is set to the wrong ISO speed or it is mis-behaving.
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Wow - loads of answers, loads of things to try. I haven't taken the Sekonic apart yet, but I will if I can't sort it any other way.
The underexposure is pretty constant at 1 stop. I generally meter with the back of the Sekonic held lightly against the lens hood of the camera to ensure it's in the correct plane as the film, and pointing in the same direction.
Manjo - does the ISO setting on the film back make any difference? I generally leave it set correctly (so far I've only put FP4 through it so I don't need to change the settings). But should it affect the exposure at all if I'm not using a metering prism on the camera?
I may take the meter into a local dealer and compare it to theirs, although my local branches of Jessops don't cater for film users any more. Indeed they managed to scrape together exactly 1 roll of Pan F between them recently - "not much call for it round here Guv'nor"
Thanks again for the help - it's appreciated.