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Thread: P25+ doesnt match my lightmeter...

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    P25+ doesnt match my lightmeter...

    I found this detail by shooting. Its not a big deal because i use the lcd histogram to fine tune the exposition.
    But anyone has noticed this ?
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    Re: P25+ doesnt match my lightmeter...

    Which body?

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    Re: P25+ doesnt match my lightmeter...

    Some details can help :

    P25+ on ALPA 12swa with Apodigitar 47xl and 24 with CF.
    The lightmeter is a Seikonic 308.
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    Re: P25+ doesnt match my lightmeter...

    My P65+ and Sekonic L-358 match perfectly well.
    -bob

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    Re: P25+ doesnt match my lightmeter...

    Curious how far off is it do you think. Maybe take the meter out in full sun at ISO 100 you should be close to 1/125th at F16. The meter could very well need adjustment. Lets not forget scene reflectance as well. White wall/ Black background can toss the histo in different directions. Need to remember your handheld meter is light falling onto subject ( incident) and does not account for any reflecting light from scene which may affect your histo.
    Photography is all about experimentation and without it you will never learn art.

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    Re: P25+ doesnt match my lightmeter...

    Now its night here, so Ill test the meter tomorrow in the sun.
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    Re: P25+ doesnt match my lightmeter...

    Yea and try to shoot a neutral scene. Grass is good since it renders pretty close to 18 percent grey and should not throw histo around compared to meter. Maybe fresh battery is need as well.
    Photography is all about experimentation and without it you will never learn art.

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    Re: P25+ doesnt match my lightmeter...

    Also need to know that you're processing in Capture One. Is that true?

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    Re: P25+ doesnt match my lightmeter...

    How uber accurate are the copal shutters in the lenses?

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    Re: P25+ doesnt match my lightmeter...

    Good point Terry . It can certainly be off for sure. Repair shop here Phoenix can actually test the shutter speeds. When I shot Hassy V lenses they where always off the shutters.
    Photography is all about experimentation and without it you will never learn art.

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    Re: P25+ doesnt match my lightmeter...

    My Sekonic 308B and 308S were off from all my canon cameras by 2/3 of a stop. I sold them and didn't bother any more..
    I am not a painter, nor an artist. Therefore I can see straight, and that may be my undoing. - Alfred Stieglitz

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    Re: P25+ doesnt match my lightmeter...

    Keep in mind that although the old gray card standard was 18% gray, current meters use 12% reflectance as their reference per ISO
    -bob

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    Re: P25+ doesnt match my lightmeter...

    12% not 18%.. I would like to know more about that. Do you know when that change was made? How would you know which reference your meter is set to? I use the incident bubble so doesn't directly influence my work, but am curious. So they should sell 12% gray cards.. don't think I have ever seen one.

    Most of the time when I shoot outside I can wing it and get within a stop and then adjust according to the histogram... pretty much what a meter would do. One of the few advantages of getting older (old).

  14. #14
    Shelby Lewis
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    Re: P25+ doesnt match my lightmeter...

    ISO isn't adhered to very consistently from camera to camera... manufacturer to manufacturer these days. I'd just calibrate your meter to your back and move on.

    My old canon 5D matched my sekonic 358 very nicely... my 5dii? Not so nicely.

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    Re: P25+ doesnt match my lightmeter...

    In the studio my RZ w/ ZD back matches up to my 758DR. My 1DsIII and 1DIII are both off by 2 stops from the meter. The 758 supports having two different configurations for camera oddness. But I think I'm just going to use the RZ in the studio and leave the 1Ds in it's bag.

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    Last edited by mvirtue; 18th December 2010 at 09:09. Reason: added info

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    Re: P25+ doesnt match my lightmeter...

    can of worms here. variables are: actual shutter speed, settable iso (usually increments are pre-selected) is metering incident or reflected, and if reflected, off of what zone value (very important)?

    what i do:

    get shutter speeds measured, usually very simple at camera shop. use these values for setting exposure, rather than what the shutter dial says

    place 18% grey card in scene, meter that using reflective metering. shoot that using same iso setting for meter and camera, bracketing by 1/2 stops, about two stops both ways

    pick best exposure in raw files so grey card registers 18%. compensate meter iso to match the selected exposure bracket and use this for all future shots.

    if you use the incident dome on your meter, it should give you the same reading as reflecting off the 18% card.

    or, and this is what i really do:

    look at a few shots that you have shot by metering and had to correct exposure setting in raw. compensate meter iso accordingly.

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    Re: P25+ doesnt match my lightmeter...

    Quote Originally Posted by mvirtue View Post
    In the studio my RZ w/ ZD back matches up to my 758DR. My 1DsIII and 1DIII are both off by 2 stops from the meter. The 758 supports having two different configurations for camera oddness. But I think I'm just going to use the RZ in the studio and leave the 1Ds in it's bag.

    --Mark
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    Did you calibrate both of the Canons & ZD with the L-785DR using the calibration target and software?

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    Re: P25+ doesnt match my lightmeter...

    Quote Originally Posted by GrahamWelland View Post
    Did you calibrate both of the Canons & ZD with the L-785DR using the calibration target and software?
    No I haven't. I've been meaning to, but actually doing work gets in the way Once I figured I was two stops off I just dropped the ISO on the meter two stops. When I used the RZ for the first time in the studio I did not think about it and just went with the reading.

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    Re: P25+ doesnt match my lightmeter...

    Quote Originally Posted by mvirtue View Post
    No I haven't. I've been meaning to, but actually doing work gets in the way Once I figured I was two stops off I just dropped the ISO on the meter two stops. When I used the RZ for the first time in the studio I did not think about it and just went with the reading.
    I hear you about work getting in the way - real work is overrated IMHO.

    Certainly the approach you're taking with the 785DR is a practical one but you're also using only a small portion of the meter's capabilities that you've paid for. As you no doubt know, if you calibrate it you'll have matching exposure base across all cameras and also dynamic range hints too based on your own actual camera bodies. I initially found the instructions pretty confusing but the video over at Sekonic's web site cleared things up significantly. I used the advanced target which only required bracketing 3 shots vs 11 - not a big deal in the overall scheme of things though.

    http://www.sekonic.com/land/dynamic-range.asp

    Btw, I do think that at the price of this meter you shouldn't then have to buy a target to calibrate it. That kind of annoyed me, especially as it's not the type of thing your local dealer has in stock at time of purchase either so I had to wait another few days after buying mine before I could set it up.

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    Re: P25+ doesnt match my lightmeter...

    Quote Originally Posted by GrahamWelland View Post
    I hear you about work getting in the way - real work is overrated IMHO.

    Certainly the approach you're taking with the 785DR is a practical one but you're also using only a small portion of the meter's capabilities that you've paid for. As you no doubt know, if you calibrate it you'll have matching exposure base across all cameras and also dynamic range hints too based on your own actual camera bodies. I initially found the instructions pretty confusing but the video over at Sekonic's web site cleared things up significantly. I used the advanced target which only required bracketing 3 shots vs 11 - not a big deal in the overall scheme of things though.

    http://www.sekonic.com/land/dynamic-range.asp

    Btw, I do think that at the price of this meter you shouldn't then have to buy a target to calibrate it. That kind of annoyed me, especially as it's not the type of thing your local dealer has in stock at time of purchase either so I had to wait another few days after buying mine before I could set it up.
    Sounds like a thing for me to explore during the downtime of Christmas.

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    Re: P25+ doesnt match my lightmeter...

    My Sekonic 358 is spot on with flash but it's a little off with ambient. The difference is not that big to worry about it. Since the only time I would use a lightmeter is when using flash, that's what I'm worry about

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    Exclamation What about aperture?

    Quote Originally Posted by Valentin View Post
    My Sekonic 358 is spot on with flash but it's a little off with ambient.
    The preceding comment that the exposures are accurate with flash but off with ambient light indicates a shutter speed problem.

    Flash exposures are only sensitive to aperture, since the shutter is normally open for much longer than the flash duration.

    The OP's problem may well be aperture-related. A flash test would be the best way to tell.

    - Leigh

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    Re: P25+ doesnt match my lightmeter...

    Quote Originally Posted by mvirtue View Post
    In the studio my RZ w/ ZD back matches up to my 758DR. My 1DsIII and 1DIII are both off by 2 stops from the meter. The 758 supports having two different configurations for camera oddness. But I think I'm just going to use the RZ in the studio and leave the 1Ds in it's bag.

    --Mark
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    Actually 3, not 2. I have zd , leaf 54s and d700 calibrated, b.c they all are a bit off one way or another, from flash meter factory. But not by 2 stops. More like 1/3-2/3 of stop.

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