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02-27-2014, 12:31 PM   #16
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QuoteOriginally posted by Ryan Tischer Quote
I only use Manual Exposure, but think this idea would be genius! Especially with the dynamic range of modern cameras...It's sort of a failsafe because as long as you save the highlights you can almost always pull out enough detail from the shadows.
Yes, it's very handy and clearly implementing it is not that difficult. Blackmagic has done it with relatively little experience in making cameras and it seems to work in 95% of the situations I have tried it in. Considering that digital photography is more about gathering good usable data for processing later, this makes a lot more sense. This does not hold true when shooting film, especially transparencies, and one should not be compared to the other at the capture stage.

02-27-2014, 10:07 PM   #17
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Hmm, that sensor split thing is not an issue that affects me. I have to really compress an HDR, for example to find the seam otherwise it is completely undetectable on my normally exposed and processed shots.
I am way more interested in solving the mandatory dark frame subtraction for long exposures. My 5 minute exposure takes 10 minutes...grrr.
03-15-2014, 01:56 AM   #18
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QuoteOriginally posted by mikeSF Quote
Hmm, that sensor split thing is not an issue that affects me. I have to really compress an HDR, for example to find the seam otherwise it is completely undetectable on my normally exposed and processed shots.
I am way more interested in solving the mandatory dark frame subtraction for long exposures. My 5 minute exposure takes 10 minutes...grrr.
I've had the sensor split happening on deep blue skies, especially when using a CIP. It also appears on some twilight shots. Bearing in mind my biggest processing weakness is cloning, this is quite an issue when it arises.
03-15-2014, 11:42 AM   #19
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I've clicked my 645D about 5,000 times and I've never seen the split sensor problem. I'm wondering if Pentax fixed it in later production models or with software/firmware? I purchased mine in December 2011.

03-16-2014, 07:48 PM   #20
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FWIW, I've had a 645D since Dec. 2010 and have never seen a split sensor problem; in fact, no problems at all.
03-29-2014, 07:23 AM   #21
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Same for me since march 2011, but only 3500 shots.
03-29-2014, 08:55 AM   #22
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The split frame issue seems to be a minority problem. I really empathize with people who have it, it would put some unfortunate constraints on the otherwise fantastic image quality of the 645D. For myself, I've run through probably 60,000 frames on my pair of 645D's and have never once seen it. (Lots of multi-frame projects for stitching, focus stacking and HDR.) If the problem did show up, I'd make a pretty strong attempt to get Pentax to resolve it.

I wonder if it's possible they could update the calibration of the sensor without replacing it; I don't know if it can be done, but it is something done with some CCD's as I understand it. Otherwise I'd ask hard for a replacement.

The new CMOS sensor should not have this issue...
03-31-2014, 07:40 PM   #23
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I had this problem with mine (manifesting not just as differing tone between the two halves but an actually visible join with artifacts along the join) - though it was only visible when the camera was used at high ISOs. I sent it to Pentax and they rectified the problem. However, as I live in a country that is not directly served by Pentax (Australia), I was without the camera for several months - which was a MASSIVE problem. The issue for me here is not that there are occasional technical problems (that is inevitable) - it is the fact that there is not a proper infrastructure to support users of this expensive kit when the problems occur (i.e. full local repair capability and/or loaners). One cannot sell cameras at this price point and be unable to support people properly through issues; such an approach is commercial stupidity. Hopefully the launch of the 645Dii will coincide with better support globally.

03-31-2014, 08:01 PM   #24
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Yeah, the support situation I think is actually a bigger barrier to increased adoption of the 645D system outside of Japan, than anything about the system itself. My first 645D was unavailable for ~10 weeks to replace a failed shutter -- the camera had to be sent to Japan for repair because there's no facility in North America that could do that work. I'm sure a sensor replacement would mean a camera trip to Japan for us N. Americans, as well.

Frankly, I doubt the situation will improve with the launch of the 645D II; I'd like to be pleasantly surprised by improved support but I'm not holding my breath for it. I decided to "self-insure" by getting a 2nd body, and I expect to maintain a pair of 645D I's and/or II's going forward. I don't want to be down for months in the event of another failure of some kind...
04-02-2014, 05:05 AM   #25
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Another major reason for these problems is that the CR Kennedy staff are not very competent. I had a few things go to them for reapir and I dread dealing with them any more as they are just not able to identify and solve often unsubtle problems.

For example:

- had a sigma HSM lens which would back focus at short distances and not focus in live view in new cameras. They changed the board, updated the firmware and returned the lens. I mounted the lens and the AF speed was about 20% of what it was before. Returned the lens waited for another two weeks (on top of 4) only to find the speed was back to normal but the original problems are exactly the same. In the end I gave up.
- had a lens front element scratched when it was left for repair due to a loose barrel. The lens had to be shipped to Japan to replace the front element.
- Started having front focus issues in low light where previously there were none. I strongly suspect it was due to a misaligned mirror or AF module. they instated there was no problem by...get this.. testing an AF chart at f4.. with a 1.4 lens.





QuoteOriginally posted by Royce Howland Quote
Yeah, the support situation I think is actually a bigger barrier to increased adoption of the 645D system outside of Japan, than anything about the system itself. My first 645D was unavailable for ~10 weeks to replace a failed shutter -- the camera had to be sent to Japan for repair because there's no facility in North America that could do that work. I'm sure a sensor replacement would mean a camera trip to Japan for us N. Americans, as well.

Frankly, I doubt the situation will improve with the launch of the 645D II; I'd like to be pleasantly surprised by improved support but I'm not holding my breath for it. I decided to "self-insure" by getting a 2nd body, and I expect to maintain a pair of 645D I's and/or II's going forward. I don't want to be down for months in the event of another failure of some kind...
04-02-2014, 05:47 AM   #26
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QuoteOriginally posted by larkis Quote
Wow, really ?

I won't want to start a pissing contest here, but that's a incredibly cliché thing to say. Sure, a lot of time time it is the photographer but having done darkroom and large format film shooting for over 10 years (and still doing it) my command over the zone system is adequate enough to know it has very little to do with digital exposure. With digital you want to get as much information into your raw as you can without clipping, that's all, and the antiquated metering found in most (if not all) still cameras does not accomplish this. The blackmagic motion cameras have a ETTR button which is convenient when you are busy shooting in the field. The zone system approach is great for a large format photography approach but not for when (for example) a heard of horses with various luminance patches of fur is running through the fame and you want to optimize your captured data.

But don't take my word for it, take your 645D and try going outside and let the auto exposure meter do it's thing while you do a 360º series of images and look at the histograms of the files.
So, you're saying the camera should anticipate where you want to centre your exposure when the dynamic range of the scene exceeds the cameras ability to capture it? Expose to the right without clipping? I don't think so, in some scene's I want the shadows more than the sky. That will always be the photographers decision, until such time as cameras can handle 5000:1 - 20,000/1 contrast.

The simple fact is, getting a camera that knows how to optimize your data is asking for a lot. That's why they have (and have always had) <drum roll> bracketing. That's why they have <drum roll> HDR. That's why there's software that will combine multiple exposures into HDR files, and masking in Photoshop in case you want to do it yourself. Let's not predicate our arguments on scenarios that dismiss huge portions of photographic practice.
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