Riddle me this...Bronica SQ-AI exposure problem.

Discussion in 'Medium Format Cameras and Accessories' started by fotoobscura, Feb 9, 2013.

  1. fotoobscura

    fotoobscura Subscriber

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    I dug out my SQ-AI to shoot snow last night and I did a test roll a few days ago to make sure things were still in tune. I noticed something odd- The 8s setting was not working at all. 4s worked fine as well as 1s and faster shutter speeds but for some reason 8s simply did not work. It looked as it if was shooting as fast as the camera goes (1/500).

    Not really sure how to troubleshoot this any further. I mean, it looks like the 8s setting is simply broken.

    Anyone else experience this?

    As far as I know the batteries are fine.

    FWIW there is a 16s and a B option. Naturally I could use bulb and time 8s but that's no fun.

    Thanks
     
  2. hoffy

    hoffy Member

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    Have you tried a different lens?
     
  3. lacavol

    lacavol Member

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    Definately switch out the 4 LR44 batteries, Bronica did specify alkaline, don't substitute for lithium. The shutter is electromagnetically controlled to hold it open; if the batteries sag, especially in the cold, then the sutter will close too fast. If the batteries are bad then it will only fire at top speed 1/500. If you have a motor drive then the drive supplies the power. It must be removed to check the small batteries.
     
  4. lxdude

    lxdude Member

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    ^^^To add to this, Bronica spec'd silver oxide as best, alkaline next, and said no to lithium. I believe both perform similarly in the cold.
     
  5. fotoobscura

    fotoobscura Subscriber

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    Morning.

    Hoffy- Sadly I had the other prime lens for my SQ-AI stolen (an 80), so I can't test out another lens

    I measured the voltage on all four of the batteries and they are putting out >= 1.5V so there's no problem there.

    As I said in my previous post, 4s worked which would have only worked if the batteries were okay.

    Thanks!
     
  6. DWThomas

    DWThomas Subscriber

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    Random musings from an owner of the previous model ...

    1) Were you checking the batteries under load? A typical behavior for weak batteries is increased internal resistance which means they read decent voltage into a minuscule load like a voltmeter, but the output drops rapidly with increased current of a real load. Alas, I can't claim to have any idea what an appropriate load would be.

    2) I believe the shutter system draws power while it's open (the reason for the optional T settings) and 8 seconds would be the most stressful, battery-wise. I also thought the Ai differed from previous models in that the shutter doesn't work at all without a battery, versus the earlier models which default to 1/500.

    3) What finder are you using -- is it passive, or one of the metering varieties. I ask this because I seem to recall the finder can override the camera body settings. But since all my finders are non-metered, I have no first hand experience.

    So I don't know if I'm even close to anything useful here. (Probably not. :blink:) Have you used 8 seconds in the past successfully? It could be that contact on the speed switch is broken or dirty. It's a shame you don't have another lens available. I like these cameras but having substitutes for the various components sure helps with troubleshooting, not to mention provides enough redundancy to keep shooting past problems that crop up.

    Good luck with it.
     
  7. fotoobscura

    fotoobscura Subscriber

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    1) No. Good idea though. So you're suggesting I attach a meter to the batteries during an exposure and check the voltage. I think I can do that with these 76's.

    2) Yes, it must. The timing is electronically controlled. (There is a 16s setting).

    3) It's a prism finder that uses the camera batteries to meter. (The Bronica AE prism finder)

    Anything to inspire more troubleshooting is useful.

    I took a photograph without the prism finder, set to 8S, and it worked. So what's a real head scratcher is why 4s works but it seems to completely ignore 8s. I guess my next test is to shoot the prism finder at 16s and see if it times it correctly. If not I can presume that the prism finder is unable to draw enough power from the batteries > 4s to close the shutter and as such is defaulting to 1/500.

    Thanks!
     
  8. Sirius Glass

    Sirius Glass Subscriber

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    Cold temperatures can cause havoc with batteries and cameras [mechanical or electronic]. Keep the camera body warm in your coat between photographs and watch for lens fogging.
     
  9. Andrew4x5

    Andrew4x5 Member

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    The shutter is in the lens, but the timer is in the camera. So if 4s and shorter work OK, it implies that the shutter is OK. Therefore problem is most likely to be the 8s setting on the speed dial - perhaps the 8s contact is corroded.
     
  10. hoffy

    hoffy Member

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    Exactly - this is what I was trying to imply above. You need to somehow eliminate either the lens or the camera from the equation.
     
  11. DWThomas

    DWThomas Subscriber

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    I have never actually sorted out the exact electrical and mechanical operations of these cameras. The fact that with no battery, we can get 1/500 sounds as though the electronic action pulls a mechanical catch in place to catch the shutter mechanism while it's open. then releases it after the set time; if that never happens, the shutter closes at the fastest speed which is marginally 1/500. Incidentally, since my earlier post I found something suggesting the shutter may draw 15 ma which I think is a pretty heavy load for those button cells. And I believe the AE finder has some LEDs and such? (more load)

    What bothers me is that if it was purely a battery strength issue and the camera seemed to work at four seconds, I would expect an eight second exposure controlled as described to be OK for more than four seconds, then maybe fizzle at five or six, not drop to a 500th.

    So, do you have another finder? If what you describe in the excerpt I quoted is the way I understand it, you're saying the shutter was OK without the prism finder in place? I thought I once heard that at least one model of those metered finders was a serious power hog -- or perhaps prone to develop that problem. Mayhaps it's less than 100% (or maybe the batteries are a bit weary -- or maybe both!)

    I'm thinking I may have avoided a lot of difficulty by doing 98% of my shooting with the WLF! :D
     
    Last edited by a moderator: Feb 10, 2013
  12. John Koehrer

    John Koehrer Subscriber

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    The batteries do need to be measured under load.
    Sometimes they will have enough poop(techie term) to give an exposure or two but then crap out when a heavier load is needed. 4S=OK 8S=NOT.
    Sometimes with warmth and rest they'll sorta kinda temporarily recover, then relapse to the dead mode.
     
  13. lxdude

    lxdude Member

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    Discovered through the process of elimination...
    :whistling:
     
  14. fotoobscura

    fotoobscura Subscriber

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    Hey Dave,

    First off, thanks for all the sleuthing on my behalf.

    I'm not certain it's 1/500 of a sec but from my *ears* it sounds like it's opening/closing as fast as possible. I agree that if 4 seconds should work, why not eight? I think the AE1 prism finder is drawing more load from the batteries (at once) that they can handle. Really the only logical explanation...Yes there are several leds in the viewfinder of the prism finder including shutter speeds and < arrows (if the exposure it outside of the capacity of the prism finder). Again, if I remove the prism finder, 8S works fine. It's not *really* a big deal to me especially considering I am generally shooting night shots at f11 or >, simply dropping it back to f8 to get 4s isn't a big deal to me. Finally, I can use a cable release :smile:

    Interesting anecdote to my Bronica issue is that there is a current trend "online" to shoot square images (e.g. Instagram of whom *forces* you go crop your images square before posting). When I post these images my "digital" friends invariably ask me to add them as a "friend" on Instagram :smile: I've been confused more than once when I see this 25 year old barista/club girl post pictures on Facebook with "rvp100" apparently listed on the "film" edge markers. Turns out that Instagram spits out borders for photographs that look like they were scanned film. I was fairly certain she wasn't shooting Velvia 100 in square format in a dark club :smile:

    Thanks again Dave.
     
  15. DWThomas

    DWThomas Subscriber

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    Ah, glad I may have been some help. I own 3 SQ-A bodies, one with an unhappy shutter release, and 50, 65, 80 and 110 1:1 macro PS lenses that I hope to be able to keep going with for a decade or two, but there isn't (that I've been able to find) much info around on what goes on inside the boxes. Someone pointed me to a service manual .pdf file for an ETRSi, which I downloaded, but it doesn't appear to cover anything but the body itself, which is only a portion of what's happening.

    The combination of irregularities you describe doesn't quite make sense to me, weighed against what I 'think' I understand about the little buggers, but that may mean, Zeus forfend, that my understanding is incorrect -- not that that has ever happened before .... :whistling: Hopefully APUG may become a 'knowledge base' for some of this stuff as time goes by and we decipher things.

    I suspect that some "data parameters" might be communicated via analog current or voltage in these beasties, since the design is pretty old. There are only a few contacts connecting the back and viewfinder to the body, implying a serial communication, although I guess it could be some sort of crude digital as opposed to analog serial hookup. I'm thinking an analog method might rack up extra current drain at one extreme or the other for ISO and light measurement. As a long time tinkerer in many fields, both hobby and professional, I own an oscilloscope and a few other things that might permit some deeper investigation -- "one of these days."

    I often tell myself "sometime in the winter, when it's too cold to be doing stuff outside, I'll dig into [insert object here]" but here it is February and I've got a million things going on. (Maybe I need to switch to "summer when it's too hot to ...")

    Anyway, good luck with it.