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Forum: Pentax DSLR Discussion
04-20-2021, 03:25 PM
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Great job!
The BMS needing to be "woken" by putting a charge voltage on it, is normal.
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Forum: Pentax DSLR Discussion
04-03-2021, 07:55 AM
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Agreed.
Very hard to tell from that amount of data. There are a lot of variables to consider. For example, the voltage at the finish of a charge will drop about 10% if left overnight. We also don't know how often the camera polls the battery for voltage data etc - I can't see a real need for the camera to check the voltage at every shot.
Cheers
---------- Post added 04-03-21 at 08:11 AM ----------
Also worth noting that these batteries use two cells in series so another source of apparent degredation is just the cells becoming unbalanced.
The PCB in the battery "should" prevent this from happening but you will see this all the time with Chinese batteries. In my adventures playing with batteries, I often find one dead cell amongst the others which has dragged the total voltage below the cutoff and prematurely ending the life of the battery even though the remaining cells may be totally fine.
I think the quality of the cells plays a big part in this phenomenon as well. As low quality cells will have more duds that find their way into battery packs causing them to fail.
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Forum: Pentax DSLR Discussion
03-31-2021, 04:50 PM
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The low voltage cutoff is handled by the PCB in the battery itself. The lifespan of the generic batteries is limited due to:
A) low quality (Chinese?) cells.
B) a battery management PCB design which is not optimal. eg. Cutoff voltage too low, high quiescent current use when battery is not in use.
---------- Post added 03-31-21 at 05:33 PM ----------
Yes, It is the normal behaviour with all batteries for the voltage to sag under load.
It is also normal behaviour for battery voltage to rise a bit after full discharge due to the voltage sag disappearing after the load is removed - but the battery is still flat.
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Forum: Pentax K-30 & K-50
05-28-2019, 05:23 AM
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Wow that's very surprising. I would be very interested to know if replacing the solenoid in this case gets it operating correctly again. This could help to identify the actual cause of the problem...
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Forum: Pentax K-30 & K-50
05-27-2019, 05:43 PM
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I wasn't aware of any reports of people replacing the solenoid and everything working, with a repeat of the failure some time later? Do you have any links?
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Forum: Pentax K-30 & K-50
05-21-2019, 05:11 PM
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Yes, it is the consensus that the only real fix is replacing the solenoid. The only points of contention is the type of solenoid which can be used as replacement.
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Forum: Welcomes and Introductions
05-17-2019, 09:58 PM
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Forum: Welcomes and Introductions
05-17-2019, 07:40 AM
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...and welcome from Perth as well.
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Forum: Pentax SLR Lens Discussion
05-14-2019, 02:34 AM
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I guess if you are able to test it before buying, should be pretty safe that things work as they should. No guarantee for the future of course but 'issues' tend to get blown out of proportion on the 'net.
(FWIW - got mine on evilbay Oz and absolutely love it)
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Forum: Pentax Camera and Field Accessories
05-06-2019, 01:28 AM
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I was also considering the same as I recently acquired my Tamron 70-200mm f/2.8. For me, I decided that I couldn't justify the price for the TC. I think for a bit more money I could get a longer lens which would likely give me better pictures if I found a good deal in second hand market. i.e. DA* 300mm
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Forum: Welcomes and Introductions
05-06-2019, 01:19 AM
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I went from a K7 to a gently used K3 and would definitely recommend that option. It has all the features you would likely ever need, it's rugged, takes the same battery as your K7 and the jump in iso performance was very noticeable.
Hope it helps
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Forum: Pentax SLR Lens Discussion
05-01-2019, 05:57 AM
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But what is the 'equivalent' level of pissed my wife will be if I buy another lens to get the 'equivalent' results in my crappy photos, that she has the 'equivalent' level of interest in, that I have in her accounting spreadsheets??
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Forum: Pentax K-30 & K-50
04-11-2019, 02:25 AM
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Sometimes the best way to learn is to do things 'wrong'...
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Forum: Pentax K-30 & K-50
04-11-2019, 01:42 AM
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Hi mate, I know you are trying to help and I appreciate your knowledge in this area but could we stick to helpful suggestions of things to try rather than telling people everything they know is wrong?
My question to the OP would be, as we don't know the "new" solenoid is actually good, does he have another he can test with?
Cheers
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Forum: Pentax K-S1 & K-S2
04-04-2019, 06:36 PM
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This.
They work pretty well with the regular PK mounts too, but obviously M mode only. Note PK/A adapters fetch quite a price online at eBay and such.
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Forum: Pentax K-30 & K-50
04-03-2019, 04:51 AM
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This is what I would do also, rather than just give up on this camera due to the apparent fault. Could be a pain if you switch between LV and viewfinder often but still...
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Forum: Pentax K-30 & K-50
03-31-2019, 09:26 PM
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When the camera is using the viewfinder it is using phase detect for autofocus whereas in live view it is using contrast detect. I assume the exposure is also calculated from the same contrast/phase detection systems.
As to why they would give different results though, I'm not sure.
Cheers
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Forum: Repairs and Warranty Service
03-31-2019, 09:18 PM
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To the OP, did you get it sorted? And what did you end up using?
Personally I use 50/50 cloudy ammonia and water, then rinse with water and dry with a blower to avoid spots.
There are lots of things that work and just as many people who will say a particular method is Ill advised or dangerous because they did chemistry at school 😉
Cheers
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Forum: Pentax K-30 & K-50
03-26-2019, 06:19 AM
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He means spring/summer is approaching...
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Forum: Pentax K-30 & K-50
03-25-2019, 11:18 PM
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Congratulations on a successful repair! 🙂
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Forum: Pentax K-30 & K-50
03-25-2019, 07:32 PM
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Well done. :) It's a fairly simple operation but very satisfying when it all works as intended.
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Forum: Welcomes and Introductions
03-22-2019, 05:13 AM
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Forum: Pentax SLR Lens Discussion
03-21-2019, 07:13 PM
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So if you have previously managed to take apart another lens and cleaned the fungus out, why are you asking if the pictured lens has fungus or not?
---------- Post added 03-21-19 at 07:22 PM ----------
This may help some:
Yashica 50mm F1.7 M42 mount |
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Forum: Pentax SLR Lens Discussion
03-20-2019, 10:00 PM
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I can't see any clear indication of fungus, certainly some dust/crud and a fingerprint. Bit hard to tell from these photos.
Hope it helps.
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Forum: Repairs and Warranty Service
03-20-2019, 09:49 PM
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Well this job should be able to be done by any decent electronics repair shop I think. Just tell them what you want and give them the various links showing the repair from this forum.
Cheers
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