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Forum: Pentax KP
12-19-2019, 09:31 AM
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Nope, I did push several shots, starting from ISO 800 to ISO 12800 for whatever it took to highlight the issue. Say, around two or three stops. On mine the 6400 shot seems the worst of the series, but now ISO 1600 doesn't seem so bad as it was before. My shot above is at 6400 too. With the other camera (the one I send in for repair) the magenta glow was significant and visible even before recovering the shadows on some shots. On the other thread they talk about amp glow on the K1 II: the two cameras share the new accelerator unit and the same processor. Could it be that something related to those components is going on?
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Forum: Pentax KP
12-17-2019, 03:07 PM
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Hello eric3929,
The camera was thoroughly tested (or so they said) after being readjusted, but then they told me that, "as a courtesy", they would send me a new body... but with the outer shell of the old one (a rep stated that they couldn't simply exchange that body for another, for fiscal reasons) so they changed the chassis and the insides, leaving the top, bottom and front plate and screen. When the camera arrived, being a bit suspicious, I checked the number of actuations of the shutter. My camera had done more than 10.000 shots, the "new" body had 3100 (+/-) actuations (I guess they took their time testing it... :hmm:
This new body was definitely more responsive than the other one; I'm quite sure that it's another, completely different body, also because the AF adjustment "floated" around -2 on the old one, while on this one it is around +6 on all lenses. I was a bit worried to make the ultimate test to see what happened with the magenta banding, but eventually I decided to wait no more.
The results? A bit mixed. The magenta on high ISO is there, from 800 to 6400, but now it is less obtrusive on the lower ISO and more visible around 6400, and not so visible at 1600 like before.
But... but if the exposure is right, the issue now is not visible, and you have to underexpose really bad and try to recover the shadow a bit too much (not so before, you just needed a normally underexposed shot at 3200 to see a bit of magenta in the lower part of the frame, recover or not). I've attached two shots, one at 6400 underexposed with shadow recovery, and a overexposed one at 12800 of the same scene, with just a bit of highlights recovery. You can judge by yourself.
G.
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Forum: Troubleshooting and Beginner Help
09-02-2019, 03:26 PM
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Hi! I too own the grip, but I've never experienced anything strange with it. If also your silver body works flawlessly without the battery grip, then the answer is simple...
At least the price for a repair should be a lot less.
Gianfranco
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Forum: Pentax SLR Lens Discussion
08-27-2019, 07:43 PM
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Dunno... I checked mine and it doesn't appear to have anything weird wrt the internal groups like the one you showed. Afterwards I had a look at a review on ephotozine, where their sample in a frontal picture seems to have a decentered retaining ring just like the sample in question... Their test was good, though, so maybe what I saw was an optical effect due to the lens not exactly frontal to the observer?
Well, if you don't feel good at spending 80 bucks on a potentially defective lens, who am I to disagree? :lol:
The only way to see if the quality is good enough or not - for you - is to check the actual pictures taken...
BTW, the 12-24 is quite sharp all around but only when stopped down. and shows almost always an annoying amount of chromatic aberrations off center... (easily corrected, but they're there nonetheless).
G.
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Forum: Pentax SLR Lens Discussion
08-23-2019, 02:39 PM
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A little decentering can be annoying but this doesn't mean the lens cannot be used. But... if what I see from the pictures is a decentered group, then it's way worse than those decentered lenses I encountered and used. But this does mean that it probably can be easily realigned, because the group simply doesn't sit where it should.
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Forum: Pentax KP
07-26-2019, 07:38 AM
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Update: I've contacted directly Ricoh Pentax and they answered quickly enough. I've been contacted by mr. Tohru Kodama, After Sales manager for Ricoh Europe.
After a series of emails trying to let them check directly one of their KP bodies, he admitted that at least in Asia there have been a few cases (but at first he said it was the first time for his knowledge), but - hopefully - the service centres know what to do, and a recalibration of the camera is enough to fix it.
Tohru Kodama
15:17 (1 ora fa)
a me
Internal
Dear Mr. Irlanda,
After further discussions there have been a few cases in Asia and each time sending the camera to a service centre for adjustment will fix the problem. It is still unknown what causes the magenta banding and not possible to replicate as the problem occurs only on cameras which require the adjustment.
Recommend that you send the camera to LTR so that they may check and make the necessary adjustments/calibration.
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Forum: Pentax KP
07-14-2019, 05:23 PM
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After several tests, the range of ISO affected seems to be from 800 to 6400. The visibility of the magenta area depends on the colour and lightness of the subject. I took many shots at 8000 and 12800 ISO where I can't see any banding at all, while on some 3200 and 6400 ISO shots it is visible on the jpegs too.
And no, I deliberately took the shots in total darkness. When you test something you must reduce the number of variables at minimum.
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Forum: Pentax KP
07-14-2019, 09:28 AM
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Thanks a lot, Steve, for taking the time to check the files.
By now, 6 out of 6 bodies show the same behaviour (edit: seven, there's the sample used by dpreview to test...)
I don't know what to think (except that I'm happy to avoid sending the camera in for repair... ;) )
Gianfranco
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Forum: Pentax KP
07-13-2019, 04:05 PM
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Steve, thanks for all the questions, I'll try to answer tomorrow. Just one thing: those shadow are pulled only to better show the magenta strip; usually I don't underexpose and then pull the shadows (and never to that extent, unless needed, but it should really be on the event of an alien landing in the woods near my house... :lol: ), I expose "normally" for my subject: in the ballet scene I could just cut away that part of the frame, there was just an invisible coreographer who could just remain invisible... I only noticed a bit of magenta shifting in the shadows there, but thought it was a faint reflection of the lights on the stage.
---------- Post added 07-13-19 at 04:56 PM ----------
Steve, are you stating that I'm a liar or what? She sent me the originals, shot the way I asked (she's a member of the Pentaxians group on FB).
BTW, have you got a KP? Would you be so kind to try and duplicate the kind of setting to see if the noise pattern shows in the same way? Camera in a dark room, finder covered and lens with cap, 1/15s and ISO ranging from 800 to 12800. RAW, of course...
if you like to check for yourself, I've uploaded four dng files here: WeTransfer
There is one of mine (one of those shown above) and three from the Texan KP owner. Sorry if I took so long to reply, but the upload speed is not what I may call fast, here...
PS: I didn't find anything about the temperature of the sensor in the Exif, just the WB Kelvin temperature. Where exactly should I look?
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Forum: Pentax KP
07-13-2019, 03:09 PM
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Update: another KP user from Texas confirms the issue. It happens quite clearly between 800 and 6400 ISO, less so from 12800 above.
Below is a shot taken at 800. We are talking about extreme shadow recovery, beware, but the color cast is visible (barely) in normal exposed shots too, if the 'affected' area is very dark.
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Forum: Pentax KP
07-13-2019, 12:15 PM
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Well, I don't know how it has been designed, but at the moment at least two collegues confirmed that their Kp samples show exactly the same noise pattern (more on the lower side of the frame (upper part of the sensor) with mechanical shutter, on both the long sides of the frame (but a bit less strong) with electronic shutter.
DeadJohn may be right, there could be components that contribute to a uneven heating of the sensor. Right now in Italy we are having quite a hot summer (over 30°C /86°F on average), I don't know if this may be the cause, but what I saw on the others' KPs is too similar (if not identical) to what happens on mine.
---------- Post added 07-13-19 at 12:20 PM ----------
A collegue used -5 stops of underexposure. With my dark frame shots it is probably more, but I can say that the issue is visible and annoying on the darker areas starting from ISO 3200 and -2 EV, as in the shot attached above.
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Forum: Pentax KP
07-12-2019, 06:47 AM
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Hi everybody,
I'm experiencing a strange behaviour on my KP. Especially on the lower part of the frame, when shooting at high ISO and with severe underexposure, there's often a meganta cast, covering maybe 1/6 of the height.
Investigating more, I saw that it's more visible when shooting with mechanical shutter than with the electronic one. Upon further investigation the issue appears like an uneven sensor noise (from +/- 3200 ISO up, with underexposure). I'm surely going to send the camera in for repair (it has less the a year). I'm adding some screenshots that hope may be helpful to better understand what's happening. The last ones are with the cap on the lens and the finder covered, in a darkroom: it's just noise from the sensor, and the last one is the same but taken with the K5 IIs, which seems to behave normally...
Is anybody able to check her/his KP to see if shooting a completely dark image and recovering in post the exposure leads to something similar?
Many thanks in advance.
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Forum: Troubleshooting and Beginner Help
06-05-2019, 07:26 AM
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I had to check on my winder as I couldn't really remember the dimensions of the part.
When I used to build models, many years ago, I often used some kind of epoxy putty. Don't recall the brand, but searching online I've found the Milliput, a two part epoxy putty, that comes also in black.
I don't know if this is what I used back then, but I'd give it a try. It should be strong enough to keep the tray in place (I'd add a thin but strong slice of metal, just in case...), of course you have to model it as close as possible to the original shape (on the part itself).
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Forum: Flashes, Lighting, and Studio
02-10-2019, 07:48 AM
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No way. The Metz flashes have no generic slave cell built in. You need to use another flash (58 AF-1 and up) to use as a master or control flash, the 48 AF-1 can be used as a slave, but only in wireless PTTL mode. Better for you to buy a simple generic transmitter and receiver, or a servo cell to couple with the flash.
Edit: of course you can use the built in flash, of the cameras the are able to, to trigger the 48 AF-1, but only in PTTL wirless mode, not in manual mode.
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Forum: Pentax Medium Format
04-19-2018, 01:52 PM
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Hi DJ,
I'd avoid to take it apart, if I were you...
I once tried to repair something that seemed a lot easier on my second 645 body but had to give up and sent the camera to the official assistance (and years later they weren't able to repair a problem with the finder of a 645n, go figure...)
Gianco
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Forum: Pentax Medium Format
10-05-2017, 03:18 PM
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Hi, I've been able to take these pics without disassembling everything. Hope they can help.
Ciao,
Gianfranco
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