Using as OM4Ti for spotmeteringgreenspun.com : LUSENET : Large format photography : One Thread
I am interested in anyone using the above. Apart from the obvious size weight issue, what other issues arise?
PS Sorry bad email
-- Stuart Gladwell (firstname.lastname@example.org), January 14, 2002
I know a few people who use their 35mm camera for their meter, as I did early on. Nothing wrong with that, as long as you've been comfortable with the readings it's given you in the past. Exposure for one format is the same for the other.
-- Todd Caudle (email@example.com), January 14, 2002.
Just a thought: if you're going to use a 35mm camera to spot meter make sure that you use a lens that's long enough. I've never used that camera, but with my Nikon, spot-metering usually means using a lens in the 135mm to 200mm range.
-- Matthew Runde (firstname.lastname@example.org), January 14, 2002.
I use an OM-4Ti as my only meter for 4x5 work. I've been fairly pleased with it as a system. The justification was 1) I wouldn't get a stand alone meter significantly more accurate than the excellent meter in the 4Ti which I already had; 2) My OM-4Ti was already calibrated for development and exposure in 35mm, so this would allow more direct conversion to LF zone system work; 3) I would want to sometimes make pictures (color, macro, or long telephoto) which I wouldn't make with my LF gear.
However I must admit, the last couple times I went shooting, the extra camera seemed awkward to have with me. I wasn't interested in using the camera at all. I was taking b/w LF photos and couldn't be distracted by taking SF photos. Still, it's there to use when I need it.
A few points:
a) Be sure that the meter in the OM-4Ti is accurate (it probably is).
b) Think about what lens to have mounted on the camera. I usually use a Zuiko 135mm as a good compromise between bulk and angle of view. I think the spot reading with that lens is about 2.5 degrees which is usually adequate. My longest 4x5 lens is 300mm, so a 35mm format 135mm lens makes a nice next step up in length. A 200mm lens would be better, but makes the camera much bulkier. A 300mm lens will give a 1 degree spot reading, just like the fanciest spot meters, but this is very bulky and I don't think anyone regularly needs only 1 degree metering. You can bring multiple lenses, but then you are really deciding to go SF shooting instead.
c) Think about bellows extension effect on the exposure. I calculate the bellows extension compensation separately after making the reading with the 35mm camera. Assuming the flare (light loss) in the SF and LF lenses is comparable (a moderately safe assumption), then the SF lens should be focussed on infinity not on the subject you are taking the reading from: Since the SF camera has TTL metering, if you focus on closer items, the extension factor for that lens will be part of that reading and you might compensate twice when calculating your final exposure. The temptation to focus while making the reading is quite high -- especially when you most shouldn't, i.e. on close objects which require greater bellows extension compensation. If you don't focus on close items, then the spot reading becomes more diffuse because the light is so profoundly out of focus -- so with my 135mm lens, the spot reading is more like 5 degrees on an object a meter away. However, for close objects, you can usually walk right up to them and meter so this is not a serious problem (don't shade the object of course).
d) be careful with your lens caps! Olympus lens caps tend to fall off easily and when using a camera as a meter it is quite likely to be handled differently from a camera you are using to shoot and the cap may well get lost.
e) be careful with the ASA/exposure compensation dial on the OM-4Ti. This dial is not very friendly on this model. If you set the ASA to the film in your LF gear it is easy to not set it back, or to twist the exposure compensation (partially) rather than resetting the ASA.
f) the multispot reading of the OM-4Ti is wonderful for zone system calculations. Just spot read at your high value, spot read at your low value and count the stops between your diamonds. For my system, 4 stops = N development, 3 stops = N+1, etc. Remarkably fast. I do this in a few seconds before choosing my film. Once I know the contrast, I choose the film and exposure index for that contrast of development and then set the ASA on the 4Ti to the value and usually take a single spot reading on a mid value (or you can meter off a different value and compensate, or you can just take an overall reading of the scene, or ...) Since the diamond of the final spot reading will move up and down the scale as you adjust the f-stop/shutter speed even after you are no longer pointing the camera at your subject, you can use this as a calculator for the LF camera's exposure quite leisurely (just don't let enough time go by for the OM-4Ti to automatically shut down)
I guess that summarizes my experience to date...
-- Eric Pederson (email@example.com), January 14, 2002.
As Eric amply explained, it works fine, even letting you scan for SBR etc...but if you want to match the capability of an ordinary Minolta Spotmeter (or equivalent) you'll need to use a 300mm lens...and that's rather outrageous to use rather than a spotmeter unless you'd be carrying the OM gear along with you anyway.
-- John Hicks (firstname.lastname@example.org), January 14, 2002.
Thank you to everybody for the illuminating replies
-- Stuart Gladwell (email@example.com), January 15, 2002.
Hi Stuart, I guess you already know that most will over expose LF film compared to 35mm. This is one difference you will have to work out if used to shooting B&W with 35mm. Best, David
-- david clark (firstname.lastname@example.org), January 15, 2002.
Works just fine for me (I'm using a EOS 3 for that purpose). In addition to the suggestions above, make sure your aperture reading is correct if you are using a variable-aperture zoom lens.
-- Q.-Tuan Luong (email@example.com), January 21, 2002.