No Light Meter

Discussion in 'Medium Format Cameras and Accessories' started by mkiernan, Mar 29, 2007.

  1. mkiernan

    mkiernan Member

    Messages:
    80
    Joined:
    Mar 1, 2005
    Location:
    NSW, Austral
    Shooter:
    35mm
    I have recently purchased a Bronica SQ-A with standard waist-level viewer, and hence no internal light meter. I assumed that as I do not have a light meter that I could use my 35ml camera (Pentax MZ-50) instead until I can save up enough to buy one. Thus I set the Sigma zoom lense to 50, standard on the 35ml SLR, to approximate the 80ml lense on my Bronica (standard of 6x6 MF). Determined the exposure I wanted on the 35ml and transfered this to the MF. However the negatives, when I developed the file (HP4 in HC110) were excessively over-exposed.

    Is anyone able to explain to me why this occured. More importantly, can anyone explain how I can use my 35ml camera, with internal light meter, as an interim light meter for my Bronica until I can afford to buy a proper meter?

    Thanks
    Michael
     
  2. Nick Zentena

    Nick Zentena Member

    Messages:
    4,679
    Joined:
    Nov 21, 2004
    Location:
    Italia
    Shooter:
    Multi Format
    Is the zoom constant aperture or variable? If it's variable did you check the actual aperture?
     
  3. David H. Bebbington

    David H. Bebbington Inactive

    Messages:
    2,364
    Joined:
    Dec 12, 2004
    Location:
    East Kent, U
    Shooter:
    Medium Format
    Did your Pentax have film in it? If not, its meter would have defaulted to ISO 100 (assuming you did not have any film speed correction dialed in).

    Regards,

    David
     
  4. Mark_S

    Mark_S Subscriber

    Messages:
    544
    Joined:
    Oct 20, 2004
    Location:
    San Jose, CA
    Shooter:
    4x5 Format
    Try shooting a roll outdoors using the sunny 16 rule, always the same exposure but a variety of different shutter speed/aperture combinations as a sanity check on both the shutter and aperture. For grins, use the same film/exposure settings and do the same with your Pentax MZ then process the films together, see if they look similar....
     
  5. BWGirl

    BWGirl Member

    Messages:
    3,049
    Joined:
    May 15, 2004
    Location:
    Wisconsin, U
    Shooter:
    Multi Format
    Michael, pm me with your email address & I'll send you a Word file with my full set of "Sunny 16" rule cards. I have a set for all 'sun' conditions and most major film types. I print them out & cut them to size & seal them in clear contact paper. They end up being close to 4"x7".
    Let me kn ow if you want them!
     
  6. wirehead

    wirehead Member

    Messages:
    169
    Joined:
    Apr 13, 2006
    Shooter:
    Medium Format
    You may need to apply a correction factor between the two cameras. Try doing a bracketed sequence.

    All of my medium format shots are done using either a digital P&S camera or my ancient Canon SLR.
     
  7. Peter Black

    Peter Black Subscriber

    Messages:
    1,001
    Joined:
    Mar 19, 2005
    Location:
    Scotland, UK
    Shooter:
    Multi Format


    A couple of considerations. First would be to check the battery in the SQA to make sure it is OK and not liable to be the source of any problem. The second would be to look into the SQA lens and make sure it was actually stopping down when you fire the shutter. The third would be to switch the Pentax to manual metering and focus. I can't see why that should make a difference, but these are all cheap/free items to check before going any further.

    There is an item on dry firing the Bronica on the link below, along with other tips/problems.

    http://www.camerahobby.com/Photo-Bronica_Tips.htm
     
  8. jnanian

    jnanian Advertiser

    Messages:
    19,116
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    great suggestion!

    i only use a meter when i am on assignment, otherwise
    i judge light and use sunny 11, after about a year i have gotten
    as good or better than my meter.

    john
     
  9. maxbloom

    maxbloom Member

    Messages:
    187
    Joined:
    Jun 25, 2006
    Shooter:
    Multi Format
    In my experience, this occurs because of a combination of field of view and average metering on the part of the 35mm. Approximating lens lengths doesn't necessarily do the job. While a 50mm lens on a 35mm camera is roughly approximate to an 80mm lens on a MF, the field of view still differs greatly by format size; i.e. although the lenses are roughly equivalent, the overall field of view is going to change greatly between 645, 66/67, and 69. The field of view of your 50mm lens is much closer to an 80mm on a 645 than on a 6x6. This was the problem I experienced when trying to use my ME Super to meter for my 6x9 graflex. Essentially, if the 35mm meters for a particular subject (this is especially true outdoors) and averages the metering, it's going to overexpose because the wider field of view on the 6x6 will let more light in. I would suggest that if you want to use your 35mm to meter for the Bronica, then switch to a wide-angle lens.
     
  10. jimgalli

    jimgalli Subscriber

    Messages:
    3,569
    Joined:
    Sep 7, 2002
    Location:
    Tonopah Neva
    Shooter:
    ULarge Format
    You're assuming the shutter on your Bronica is working perfectly. It may not be. Lots of variables here. But your thinking is sound. When I first started in medium format with my Mamiya Universal I bought a twin camera platform and the Mamiya was sitting on the same tripod as the Nikon. I'd meter the chromes with filters and all and usually also take the photo with the Nikon, then I'd put the filters on the Mamiya and have it simply do the same as the Nikon did. Shot lots of good Velvia that way.
     
  11. Ole

    Ole Moderator Staff Member

    Messages:
    9,284
    Joined:
    Sep 9, 2002
    Location:
    Bergen, Norw
    Shooter:
    Large Format
    Even on a fixed-aperture zoom lens, there can be considerable difference between the f-stop and the light transmission. The f-stop is a mathematical aperture, which is not corrected for light loss in the lens. The Bronica lenses are simpler in construction than zoom lenses, and transmit more of the light.

    I wouldn't have thought that the difference could be enough to cause significant over-exposure, though...

    You could see if you can find a cheap fixed 50mm lens for the Pentax, that would be closer to the Bronica lens in terms of light transmission.
     
  12. mkiernan

    mkiernan Member

    Messages:
    80
    Joined:
    Mar 1, 2005
    Location:
    NSW, Austral
    Shooter:
    35mm
    Thankyou to everyone who replied to my posted question. There were many useful suggestions and offers of help. I will probably try the estimation approach first as I now realise that there may be too many variables to sort out in trying to calibrate two cameras. Given I do ultimately intend to purchase a light meter some day, it may be best to wait until then as I will probably need to run a few tests to get these to interact reliably.

    Thanks gain.

    Michael
     
  13. Ulrich Drolshagen

    Ulrich Drolshagen Subscriber

    Messages:
    533
    Joined:
    Mar 14, 2005
    Location:
    Germany
    Shooter:
    Medium Format
    Hi Michael,

    sunny 16 is really a viable approach but I'd as well look at a well known auction site for an old Weston Master V. Examples still in working condition go for a song there. So for a shiny new one you can wait till christmas then ;-)

    Ulrich
     
  14. haris

    haris Guest

    As prices of secondhand meters can be as low as 5 to 10 EURO, there is no reason not to buy one...
     
  15. jrydberg

    jrydberg Member

    Messages:
    84
    Joined:
    Mar 6, 2007
    Shooter:
    Medium Format
    But what kind of meter is that?

    I do not want to have to run over to the objective and read the light, esp if I shoot landscape :smile:. The closest to a handheld spotmeter must be a SLR or DSLR.
     
  16. Ulrich Drolshagen

    Ulrich Drolshagen Subscriber

    Messages:
    533
    Joined:
    Mar 14, 2005
    Location:
    Germany
    Shooter:
    Medium Format
    If you are not one of the zone system guys, there ist no need for a spotmeter. You can get away with simple object or incident light metering generally.

    Ulrich
     
  17. Frank R

    Frank R Subscriber

    Messages:
    345
    Joined:
    Jan 30, 2006
    Shooter:
    Large Format
    No running needed. The sun falling on distant mountains is the same falling on your head. It will provide the same reading on an incident meter. If you are shooting into shadows you can step into nearby shade. Its not hard and it works remarkably well. An incident meter is pointed back at the camera from the subject not at the subject like a reflective meter.

    I recommend looking for a Norwood Director.