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03-09-2013, 06:39 AM   #16
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just try alkaline AA's they run down quickly, if the problem goes away when the batteries are low eneloop's are your solution


06-01-2013, 08:35 PM   #17
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Hi, all -

I'd like to resurrect this thread because I'm having exactly the same problem in exactly the same circumstances. @csmoore...any luck since your last posting?

Just to summarize:
- Genuine Pentax m42 adapter on K-r
- Any m42 lens causes erratic mirror flop

The mirror flop is rather bizarre, too, as the OP's sounded. Sometimes it works fine. Other times I get a mirror flop with any button press of the camera. Today I even had it switch to continuous shooting mirror flop. If it helps, switching to Live View sometimes alleviates the problem for awhile. I'm using a fully charged battery from the original kit.

Any ideas?
06-02-2013, 05:28 AM   #18
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Sorry to hear you're having the same problem, but you're in luck!

I bought an AA batery adapter on ebay for $3, and went out and got some rechargeable energizer batteries (regular AA's wouldn't work) and the problem was fixed completely. I haven't had any problem since when using the rehargable batteries, and I actually get a longer charge out of them then I do the regular battery.
06-02-2013, 05:51 AM   #19
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QuoteOriginally posted by ofer4 Quote
I'm using a fully charged battery from the original kit.
All batteries gradually die. As you use and recharge them "fully charged" is at a lower point each time. The issue isn't voltage, but current. It is like a clogged fuel filter on an automobile - the gasoline itself is just as potent as always, but if the motor doesn't get enough gasoline you have less power and the car runs poorly.

If you are using LiON batteries for your K-r, I recommend replacing them regularly - two years at most, and perhaps a couple times a year.

Sanyo eneloop batteries seem to have a longer lifespan than LiON. I don't think there is a substantial difference in the number of photographs between a brand new LiOn and brand new eneloops - but after a year's use, the eneloops have more capacity than LiON.

It is your choice as to which battery technology you decide to use, but right now, you need new batteries.

06-02-2013, 08:42 AM   #20
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Thanks, Jim. While a new battery is likely the cheapest and easiest option, I'd like to understand the diagnosis more before operating.

Some things that confuse me...

1. This problem ONLY occurs with m42 lenses. In fact, I can reproduce the problem with just the adapter and no lens.

2. M42 lenses have no electrical contacts with the camera. The adapter is the only thing that touches the camera, so everything that requires power happens internally.

3. Shouldn't even dying batteries (as well as the body) have voltage/current regulators?

4. Unlike the infamous mirror flop issue (, this problem happens whether the battery is fully charged or nearly dead.

06-02-2013, 12:05 PM   #21
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Any regulation happens on the device side. battery voltage is determined by the number of cells and type of chemistry. the device (the camera here) determines the current draw and the battery does its best to meet that demand. As a battery gets older, it is less and less able to supply electrons at the levels requested by the device (current - also called amperage)

I cannot tell you specifically how the camera works with a M42 adapter, but it is entirely possible that the camera may draw higher current loads in the absence of newer lens designs. Remember that a M-series or older lens shorts all the contacts other than the 'A' contact.

Regardless, the evidence is pretty clear that in the majority of mirror flop cases, the problem was solved by putting in new batteries - not just freshly charged batteries.
06-02-2013, 01:27 PM   #22
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Hi, Jim. I really appreciate the follow-ups. I'm still thinking that the problem might be adapter-specific, though. Here's why...

I do not have a spare battery at the moment, but I do have the AC adapter for the K-r. I tried it with the adapter instead, and I get exactly the same problem.

*Note: It's possible that the problem (just like the mirror flop in the K-5 on fully charged batteries) is from too much juice. A fully working battery or the AC adapter might be drawing similar currents, whereas AAs via the adapter might drop just below some threshold. This may also explain why live view fixes the problem: The additional load of the screen draws less power elsewhere.

As an additional, quirky piece of evidence, consider the following test...

- I inserted the m42 adapter with no lens and turned on the camera.
- I then fired off a few shots until mirror flop began.
- Without turning off the camera, I removed the adapter.
- The mirror flop continued(!)
- However, if I turn off the camera OR switch live view on/off, the flopping stops.

So, somehow the presence of the adapter changes/trips a setting somewhere in the camera--probably very low-level--that is not reset until the camera is turned off (or live view used). I'm beginning to suspect that this is either a design problem or a problem with my camera. It works perfectly otherwise, though.

I'll keep investigating. I fired off a message to Pentax yesterday...will post back here when the work week resumes. If any K-r users have successfully used an m42 adapter, please let me know.

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