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Thread: Canon A-1 advice

  1. #1

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    Canon A-1 advice

    Hi folks! I habe been shooting Canon A-1 that i recently got in pretty good shape since no one used it for years.

    The problem is, im getting a really bad exposure in my shots, mostly underexposures. I'm using the camera's meter and even applying exposure compensation and even that way i get the same results. Also it appears to require a lot of light for the same shot than a DSLR would require.

    I'm using a Kodak Ektachrome 100 film and a canon 50mm prime at f/1.4 and a cheap 24-70mm zoom at f/3.5

    Is there a secret to shooting on film in general? Is there a secret with the camera? please help!

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    Re: Canon A-1 advice

    No secrets, none at all. But you must make sure to set ASA speed for the film you use.

    Of course it is possible that the electronics don't work as they should, but it is uncommon.

    There are ways to check shutter times, and you can check that stopping down system works as expected, by looking at the lens when releasing the shutter. If you do so with just room light, the lens should not stop down a lot. If it does, you have found the culprit. the automatic stopping down.

    A possible cause or the problem might be that you have an older lens that is not compatible with automatic stopping down. Those lenses fit the camera but are not FD, but FL, with the same breech lock, but without the Auto setting. If the lens does not have an "Auto" option on its diaphragm ring, Then the lens will stop down to the value to which you set it. Such a lens can only be used in manual mode with stopped down metering.

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    Re: Canon A-1 advice

    Quote Originally Posted by Nitrouspizza View Post
    Hi folks! I habe been shooting Canon A-1 that i recently got in pretty good shape since no one used it for years.
    Hi Pizza

    Silly question, I know, but have you checked the battery?

    Page 20:

    http://jameskbeard.com/Photography/L...%281978%29.pdf

    Maybe that helps.

    Cheers
    Wolf

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    Re: Canon A-1 advice


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    Re: Canon A-1 advice

    Thanks guys. AgfaB2 Yes the battery is alright it was a brand one but maybe i'm checking that out because it was on its last days.
    Melkus thanks bro i've already checked it out it was really helpful (:

    Inkanyesi i think the shutter speeds are alright and both of my lenses are automatic. I think maybe it was really the battery dying.

    How does stopped down metering works? i really don't understand it

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    Re: Canon A-1 advice

    I am wondering if the fault might not be in the film. Was it fresh, or at least had it been stored under controlled conditions such as refrigeration or in a freezer?

    I shot with the Canon A-1 as my primary film camera for many years and never had any exposure problems except when I attempted to use a linear polarizer...

    That was years ago. I never shot film again after I purchased the Canon 10D. I now shoot with a 7D and a 40D...

    Using ISO 100 at f/16 on a normally bright sunlit day and shooting a "normal" scene without either a preponderance of dark nor light areas; what shutter speed did the camera select? If it was far off from 1/100 second, the camera's meter may very well be at fault!

    If you have a hand held meter or know someone with such a meter; you could check the camera's exposure against the meter. Or, you could check the camera exposure against another camera, either film or digital...
    Last edited by rpcrowe; 13th January 2013 at 07:27 PM.

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    Re: Canon A-1 advice

    Quote Originally Posted by Nitrouspizza View Post
    Thanks guys. AgfaB2 Yes the battery is alright it was a brand one but maybe i'm checking that out because it was on its last days.
    Melkus thanks bro i've already checked it out it was really helpful (:
    Inkanyesi i think the shutter speeds are alright and both of my lenses are automatic. I think maybe it was really the battery dying.
    How does stopped down metering works? i really don't understand it
    Glad we were able to help.

    This explains metering better than I could do it (I'm not a native english speaker).

    http://camerapedia.wikia.com/wiki/Stop_down

    Cheers
    Wolf

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    Re: Canon A-1 advice

    Quote Originally Posted by rpcrowe View Post
    I am wondering if the fault might not be in the film. Was it fresh, or at least had it been stored under controlled conditions such as refrigeration or in a freezer?

    I shot with the Canon A-1 as my primary film camera for many years and never had any exposure problems except when I attempted to use a linear polarizer...

    That was years ago. I never shot film again after I purchased the Canon 10D. I now shoot with a 7D and a 40D...

    Using ISO 100 at f/16 on a normally bright sunlit day and shooting a "normal" scene without either a preponderance of dark nor light areas; what shutter speed did the camera select? If it was far off from 1/100 second, the camera's meter may very well be at fault!

    If you have a hand held meter or know someone with such a meter; you could check the camera's exposure against the meter. Or, you could check the camera exposure against another camera, either film or digital...
    Hey! that's something i never checked! When I got the zoom lens I mentioned earlier, I began using a linear polarizer. Why does it affect the camera? maybe that's what is throwing the metering off

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    Re: Canon A-1 advice

    Quote Originally Posted by Nitrouspizza View Post
    Hey! that's something i never checked! When I got the zoom lens I mentioned earlier, I began using a linear polarizer. Why does it affect the camera? maybe that's what is throwing the metering off
    A linear polariser lets only polarised light through, which may be a problem when there are reflecting surfaces in the path to the light meter. Reflecting surfaces that are metal will not affect the polarised light, while non-metallic surfaces, as those in semi-transparent mirrors and in the viewfinder prism, can twist polarisation or in worst case subdue the polarised light, thus misrepresenting the light level. So the viewfinder, and the light meter, will receive a different picture than the one that will reach the sensor. The light that passes a semi-transparent mirror is in part polarised by that mirror, and this throws any measuring in that path of light off if the light comes polarised from the lens.

    That's why circular polarisers were invented. They receive primarily light that is polarised in one direction, but twists that polarisation after it passes the filter, to all directions, in order to have it transmitted through the rest of the optical path, the chain of various reflective and transmissive surfaces, without being adversely affected.
    Last edited by Inkanyezi; 14th January 2013 at 05:33 PM. Reason: correcting typo

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    Re: Canon A-1 advice

    Quote Originally Posted by Inkanyezi View Post
    A linear polariser lets only polarised light through, which may be a problem when there are reflecting surfaces in the path to the light meter. Reflecting surfaces that are metal will not affect the polarised light, while non-metallic surfaces, as those in semi-transparent mirrors and in the viewfinder prism, can twist polarisation or in worst case subdue the polarised light, thus misrepresenting the light level. So the viewfinder, and the light meter, will receive a different picture than the one that will reach the sensor. The light that passes a semi-transparent mirror is in part polarised by that mirror, and this throws any measuring in that path of light off if the light comes polarised from the lens.

    That's why circular polarisers were invented. They receive primarily light that is polarised in one direction, but twists that polarisation after it passes the filter, to all directions, in order to have it transmitted through the rest of the optical path, the chain of various reflective and transmissive surfaces, without being adversely affected.
    Thanks Urban,

    I never knew the reasons that a linear polarizer impacted exposure with certain cameras. I experienced it first with a Pentax ME and complained about this problem to a Tiffen representative who was giving a presentation to my U.S. Navy Combat Camera Unit.

    He was the one who informed me that I needed a CPL. About two weeks later, he sent me a complimentary Tiffen CPL. BTW: At that time Tiffen filters were considered as very good. They were the filters we used for motion picture photography.

    We generally used a Wratten 85 filter to convert the 3200 Kelvin Ektachrome Commercial film to daylight. That reduced our ASA (now ISO) from 25 for 3200 K. lighting to ASA 16 for daylight with the 85 filter. That gave us a usual exposure of f/8-f/11 daylight work...

    Removing the Linear Polarizer helped my exposure problems with the ME and substituting the CPL worked just fine. I never investigated why a CPL works and a Linear Polarizer does not. I just acepted that at face value and from then on purchased only CPL filters when I wanted a polarizer. Thanks again for the insight!

  11. #11
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    Re: Canon A-1 advice

    Quote Originally Posted by Inkanyezi View Post
    .. But you must make sure to set ASA speed for the film you use. ...
    This. Did you make sure that you've set the ASA/ISO on the camera to match your film (iso 100)? And that your exposure comnpensation is set to 1? See the bottom section of: http://www.mir.com.my/rb/photography...etting_the_ASA

    Canon A-1 advice

    If it's set for a higher iso rating, or with negative exposure compensation, that could explain consistent underexposure.

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    Re: Canon A-1 advice

    You mention stopped down metering. Make sure the stopped down lever is not pressed when mounting the lens. A feature if Canon FD lenses is that on mounting they engage a lever and this opens up the aperture, which is then closed down just before exposure.

    Incidently do not let the bottom of the camera get wet, under the base plate are some electronics, my A1 failed when these corroded.

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    Re: Canon A-1 advice

    The problems of linear polarisers were largely unknown before the event of the Canon Pellix camera, which did not show any viewfinder image at all at some polariser angles. The viewfinder went totally black.

    However to a lesser degree, all SLR prism viewfinders may suffer, as reflections inside the prism are polarised. And also the first TTL measurement systems were a little affected, as light passed through the semi-transparent parts of the mirror was partially polarised. However, the difference was hardly noticeable in that case, so before the Canon Pellix, polarisers usually were linear. For movie cameras however, circular ones were made, as they had beam-splitter prisms to divert the image to the viewfinder. The beam-splitter has the same problem, as it reflects light polarised only in a certain direction. Thus the viewfinder image may be blackened out totally with a linear polariser in front.

    As long as light is measured with an external meter, and the image is not diverted to the viewfinder with a semi-transparent mirror, there is really no problem with a linear polariser. It was not until early sixties that TTL measuring SLR existed and very few cameras had semi-transparent solutions for diverting the viewfinder image. Still few have, but the semi-transparent mirror of SLT cameras will not work well with a linear polariser, and light measurement is thrown off in all cameras that have some semi-transparent reflecting surface diverting light somewhere in the light path. Hence, mirrorless cameras won't be affected, as they have nothing in the optical path except the sensor and its filters.

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    Re: Canon A-1 advice

    Correct me if I am wrong, but I thought circular polarizers are required for AF lenses. I somehow remember that CPL became common place when auto focus lenses became the norm.
    Sorry that somehow this thread has wander so far from A. Rodriguez post about Canon A-1! The A-1 was the last Canon I used before switching to Nikon; I was mad that Canon changed their lens mount on me. Thinking back, actually I didn't have that many lens to begin with

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    Re: Canon A-1 advice

    Quote Originally Posted by pthoutex View Post
    Correct me if I am wrong, but I thought circular polarizers are required for AF lenses. I somehow remember that CPL became common place when auto focus lenses became the norm.
    No, technically, it is not related to the lens itself.

    But it is required for the AF systems that depend on a semi-transparent mirror, that deflects certain polarisations. In all DSLR:s there is such a mirror segment in the centre of the mirror, deflecting light toward the viewfinder. Also in SLT cameras one such mirror deflects the image to the AF sensors. So, in some orientations of a linear polariser in front of the lens, less light will reach the sensors and make AF uncertain, more so in SLT cameras than in DSLR.

    Cameras that use the sensor for all measurements are not affected by the polarisation, and for such a camera, you won't need a circular polariser. The linear works equally well. It is the non-metallic reflecting surfaces that cause the problems encountered with linear polarisers. The first SLR camera where this occurred was the Topcon Super D, and at that time there was no buzz about the problem. The AF of DSLR cameras does function also with a linear polariser, but may become uncertain under some conditions. The SLT cameras however are deeply affected by polarisation of the incoming light.

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