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07-23-2014, 06:57 AM   #1
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Odd behaviour from Super A - aperture doesn't stop down

I have a Super A I've yet to run a roll of film through. I have dry-fired it quite a few times and have found that sometimes it starts firing the shutter but without stopping down the aperture to what is set on the lens. I am using M lenses.

If I take the lens off I see that the stop-down lever in the mount barely moves when it does this. I think it also flashes P125 in the small screen on top, but as I need to be behind to see the screen but in front to see the aperture, it's hard to be 100% certain if it always does this.

Has anyone seen this behaviour? Could it be due to low batteries or is there something more serious happening?

Many thanks

07-28-2014, 07:12 AM   #2
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Hi I have only ever had aperture problems whith one lens on my Super A and that happens on my K100d super as well however you may find something in the manual Link Here as there is a list of errors around page 30ish
07-28-2014, 11:17 PM   #3
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Thanks for the link -I've had a look but no help. I think it's a battery problem but it has new LR44s (second set) and behaves the same. LR44s seem to be only available with alkaline chemistry these days so there's nothing else I can try. I have read that devices originally designed for batteries with other chemistries can have problems due to differences in voltage etc.

I've had another play and sometimes it just goes into 'P' mode and the aperture doesn't stop down, though that shouldn't be possible with a lens without an 'A' setting.
07-29-2014, 02:18 PM   #4
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Hi Jonathan,

I found some SR44s from a seller on ebay when trying to get a KX working, although I don't think it will help much. I presume you've tried cleaning the contacts on the lens mount.

Does the DoF lever stop the aperture down (it will always stop an A lens in 'A' to minimum aperture)? Maybe cautious cycling of the DoF lever might help (or might not)!

I think the stop-down lever on the 'A' series cameras moved proportionately to the aperture the camera wanted to use - which might explain only slight movement?

John.

07-30-2014, 12:02 AM   #5
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Hi John, I've tried cleaning the contacts, though not with alcohol yet. I saw some 1.4v zinc-air batteries of the same size yesterday and was wondering if they might provide a more consistent voltage? Not sure how long they'd last though.

There's no physical problem with the lever - it moves smoothly. It's just that the camera sometimes thinks it's in P mode.
07-30-2014, 07:59 AM   #6
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QuoteOriginally posted by Jonathan Mac Quote
LR44s seem to be only available with alkaline chemistry these days so there's nothing else I can try.
Your camera was designed to use SR44 silver cells. Those have a long life and a more consistent performance than the alkaline LR44. Both types have the same voltage (1.5v) when fresh, but the LR44 voltage drops significantly as the battery is depleted. Here in the U.S., both types are readily available with the silver cells being more common.

As for the aperture lever...It should move full range when no lens is mounted and the mode is on "B".

In regards to "P" mode...that should only happen if the "A" contact pin (the one that is recessed with a black insulating ring) on the body is engaged by the lens. Cleaning should not make any difference in your case. The same would be true for voltage.

I suspect that your camera has an internal fault.


Steve
10-13-2014, 10:11 PM   #7
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I took this camera out on an organised photo-walk at the weekend, having run 25 shots through it after changing the alkaline batteries for better silver-oxide ones, and it let me down again. I had thought that the better batteries had fixed the problem but no.

Does anyone know if it's possible to permanently disable the "P" option by severing a connection to one of the mount contacts?
10-13-2014, 10:55 PM   #8
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As stevebrot correctly mentioned, the issue with this camera has nothing to do with the "P" mode. The aperture control mechanism is not working. Even in manual mode, this same mechanism moves the aperture lever on the lens. Sadly the part is no longer available. Maybe a technician could take the camera apart and try lubricating the mechanism but they might not be excited to do a lot of work for something might not produce results.

10-15-2014, 08:05 AM   #9
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That is not a battery problem, does it work OK with other lenses?
When you press the depth of field preview lever, does it change the aperture?

Using P mode on the M lenses is not the best idea, even though it should work as A mode
I gave mine away, so I can not test anymore.
10-15-2014, 08:15 AM   #10
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I just took mine out and checked with M lenses - works perfectly and stops down as expected. Also correctly adjusts the speed in P mode with M lens.
10-16-2014, 11:22 AM   #11
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I seem to recall a post where someone had problems with the aperture lever on the body sticking or not moving completely. He said Eric Henderson told him to try putting a drop of lighter fluid on the lever and if this freed up the problem to then put a drop of oil on it. He didn't say what oil to use though.

It goes without saying you want to take care and not flood the camera with these fluids.
10-16-2014, 01:29 PM   #12
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A drop of lighter fluid wont hurt anything....
Since Jonathan is in Spain, lighter fluid is "Nafta para encendedores"
and probabably a drop of sewing machine oil would do it
10-16-2014, 01:34 PM   #13
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It can't be a physical problem with the lever as the camera thinks it's in P mode, which is not possible except with A lenses. I'm using it with M lenses.

I think I'll open it up and have a tinker, as it's already severely unreliable I've not got much to lose.
10-21-2014, 03:29 AM   #14
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zcv

I have a Super A I've yet to run a roll of film through. I have dry-fired it quite a few times and have found that sometimes it starts firing the shutter but without stopping down the aperture to what is set on the lens.



_____
shafiq
10-21-2014, 01:45 PM   #15
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QuoteOriginally posted by asad ali Quote
I have a Super A I've yet to run a roll of film through. I have dry-fired it quite a few times and have found that sometimes it starts firing the shutter but without stopping down the aperture to what is set on the lens.

_____
shafiq
Does the screen show it in "P" mode even using a lens not in the "A" position?
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