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School me on the A900 meter

Can someone please teach me how to use the meter on the Sony A900? Honestly, I don't have a clue and can't seem to figure it out. The histogram is spot on relative to the captured file, but if I try to use the meter reading from either a Sekonic 308b or Pentax spot meter, the resulting image is way overexposed. FWIW, the two hand held meters agree. If I use the in camera meter on aperture or shutter priority, the results are all over the map, but tend to be dark. The only way I get the expected results are with the in-camera spot meter and placing the metered value where I think it should fall. Lenses include both chipped Minolta as well as Leica and Zeiss with un-chipped adapters. The results are the same.

What am I doing wrong?
 

Eoin

Member
Difficult to say what's going on. All I know is I find both my a900's tend to under expose by about 3/4 of a stop with the full metering pattern.
I tend to use the neutral setting in the raw setup and have dialed in -1 in the zone paramater which seems to work quite well.
This leave the exposure compensation effectivly at zero and I can make normal adjustments as I see fit with out having to think and calculate the effective adjustment if I had a default of .7.
 
I'm assuming you mean MC/MD lenses when you refer to "Chipped Minolta". Generally you will want the chip to indicate the maximum aperture, and more importantly leave the camera set so that it thinks you are using the maximum aperture available with that lens. If you want to use f8 for example, meter the scene while stopped down at f8 while the camera thinks it's using the maximum available aperture; otherwise, the camera will think that the lens will stop down at the time of exposure and compensate for this. The result will be overexposed.

I have found that converted lenses, when stopped down, may under- or over-expose by as much as a stop even when taking the above into account -- but they wil do so consistently at a given aperture setting on a given lens.
 

douglasf13

New member
Dave is correct in that, if you're using a chipped lens, make sure that your aperture set in the camera is always set to your lens' lowest value. ie. if you're using a 50 1.4, the aperture in camera should always be set at 1.4 This is a little trickier if you're using a chip that has multiple settings options.

Also, keep in mind that not all camera companies meter the same, and that is why programmable light meters exist: http://www.sekonic.com/products/Sekonic%20L-758DR%20DIGITALMASTER.asp
 
In that case, Let's assume that you have checked the obvious -- aperture blades are not sticking, ISO/ASA settings match between camera and meter... it's possible you are simply shooting scenes that confuse the light meter. Are you evaluating results by looking at RAW or out-of-camera JPEG? Are you using any styles/custom styles? Exposure compensation?

Can you post some of the problem images, preferably with EXIF intact?
 
Well, I learned me how to use one a them meter thangs. Bottom line is it was my raw processing software, not the camera (unfortunately I got what I paid for). Back to C1 and all is good.

On a side note, I shot several frames with UniWB and they had both extended dynamic range and better color when imported into C1 compared with images shot with AWB or a fixed color temperature.
 
Glad it was minor. :D

UniWB is an incredible help. Very satisfying too. Nothing like circumventing automation and winding up with a better result to make your day. :)
 
H

hardloaf

Guest
Well, I learned me how to use one a them meter thangs. Bottom line is it was my raw processing software, not the camera (unfortunately I got what I paid for). Back to C1 and all is good.

On a side note, I shot several frames with UniWB and they had both extended dynamic range and better color when imported into C1 compared with images shot with AWB or a fixed color temperature.
Is that what you are talking about? Quote from unpublished yet FAQ:

Why my Raw files look underexposed (dark, gray veiled) in RPP compared to other converters?


Because they really are underexposed. By default RPP shows images as they captured by camera in Raw with only necessary tonal range adjustments and they may look darker than you expect. Usually this happens because your camera light meter is calibrated to some low gray point value by camera vendor. Most (if not all) modern DSLR cameras do this to preserve more highlights and most of other converters quietly apply compensation to your image to correct that.
There are two ways to resolve this - apply exposure correction in RPP or adjust the camera light meter.
For exposure correction try value 0.7 in Compressed Exposure field (the big one, at the right side). Usually this is enough, but some cameras may require different amount. This way RPP will behave the same way as other converters, except that you’ll be aware of the change and can fully control it. You may also use the same value with regular Exposure slider but in this case your highlights may get abruptly clipped. Compressed Exposure though will gently roll off your highlights and preserve a lot more details there, like it happens with film.
Adjusting your camera meter is a more complex procedure and I’d recommend this option only for advanced users who understand how metering works and all possible implications. You’ll have to check if your camera has option to apply some kind of metering bias. This option called differently for different cameras and you may need to dig through your camera manual.

 

douglasf13

New member
Well, I learned me how to use one a them meter thangs. Bottom line is it was my raw processing software, not the camera (unfortunately I got what I paid for). Back to C1 and all is good.

On a side note, I shot several frames with UniWB and they had both extended dynamic range and better color when imported into C1 compared with images shot with AWB or a fixed color temperature.
If you have C1 set to the film-like tone curve, and you're not blowing out things all over the place, then your images are underexposed. Set the C1 curve to linear, and zero everything else out, and you'll get a better idea as to how you're exposing. Like Andrey implied, it sounds to me like you're underexposing and then allowing your converter to boost things to make them look "right," just like the camera's jpegs do without some tweaking. If you use a more sophisticated converter like RPP or RT, it won't do the automatic boosts, and you'll see what you're actual exposure looks like.
 
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