polarizer and the ftb meter

Discussion in 'Canon FD' started by georgejonesie, Aug 7, 2020.

  1. is there any KNOWN issue or tendency of the light meter to give false results when used with a circular polarizer?
  2. From memory, but I seem to recall reading years back that the selective metering system of the FTb (which acts like its own polarizer) will give false readings when used with a polarizer. But don't take this to the bank.
  3. Edit: I found some old book on FD Canon cameras and a conventional polarizer will give inaccurate readings when used on an FTb (for the reasons mentioned in my first post). A circular polarizer will work on a FTb (and F-1), and give accurate meter readings.
  4. If you don't have a circular, you can try this with a conventional.

    How To Select and Use CANON SLR CAMERAS -- Carl Shipman, 1977
  5. use a hoya cpl.

    Im asking because i get vastly different results from how i place the needle in the circle and just wondered if it was my cpl causing an issue.
  6. If "cpl" stands for circular polarizer, and you get "vastly different results" in your meter reading when you place it in front of the lens, I would say this polarizer is causing the meter to give a "false result" just as other types do.
  7. The text around Shipman's instruction box posted above, doesn't mention a different outcome with different polarizers.
    But that's his book.

  8. im not sure if its just the light meter or just the CPL.... but when i am using 200 iso gold color/color plus the film comes back very washy color looking if i get the needle in the top half of the circle when i balance it out. but looks ok when i only use the bottom of the circle for balancing.

    pro image 100 iso merely seems to be BRIGHTER to the eyes when i use the top half, but normal/slightly muted when i use the bottom.

    gold color/color plus 400 is best when using the bottom of the needle. especially in bright light. in bright light the top half of the circle commonly makes the scans seem faded.

    trix400, top half makes the lighter colored spots seem brighter, and i dont feel that ilford c41 black and white cares either way.

    i havent used my lenses without a CPL since i saw the difference it made to leaves and sky
  9. I assume there is something going terribly wrong? -
    I never had a chance to borrow a working FTB but how much does that circle on the aperture needle cover? Half a stop over or under exposure? Why should that little mean a lot on color negative film, the most forgiving material ever invented?

    If your polarizer in use was non circular, you should be able to see rotating it having a significant impact on your meter read out. If that isn't the case: I'd start questioning my built in meter in general. Its old. It might be off (due to age &/ previous abuse).
    in that case figure out to which corrected ISO you have to set your meter for good results and shoot on?
  10. You can get an accurate modern hand held exposure meter for the cost of a few wasted rolls of film.
  11. Or just download a light meter app for your phone. They're accurate to within a 1/10th stop of an actual light meter, and probably at least as good as as a functioning meter on an FTB.

    I've used an app with cameras that don't have meters or to double check exposure on cameras with meters I don't particularly trust.
  12. Which ones would you recommend? How cheap are they? - No intention to troll or derail! - "Accurate modern" sounds like Sekonic to me, starting out at 200+x€? - I have Gossens laying around, whatever those might be now...
    Wasted rolls of film: I guess I'd waste 2/3 bracketing and wager another exposing according to my conclusion? After that a meter should be sufficiently known? Or do they have scarily non linear errors to worry about too?
  13. No worries, there's a difference between trolling and gently challenging a perhaps hastily formulated statement. Perhaps I was exaggerating, it's a few years since I bought my Polaris for £70. But I recently won a Sekonic L-438 View Spot Meter in with a lot of other photo bits for £30 plus postage. They are there if you are patient.

    I was just trying to suggest that while there are a lot of variables and uncertainties when using old cameras, exposure measurement doesn't have to be one of them.
    Jochen likes this.
  14. Grats on the Sekonic deal!
    I think I get what you mean and should try to replace those darn 9V battery clips in 2 of my Gossens and look & see, what I have in them.

Share This Page