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06-27-2015, 09:41 PM   #106
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The S/N logic only applies if you want to get the largest capture of light by shooting as wide as possible. Its not terribly applicable to landscape shooters, for example. At comparable apertures, in terms of the apparent depth of field, the 645Z is well ahead.

Most of the 645Z's new lenses have shake reduction in the lens (28-45 and 90mm). It would seem likely that forthcoming lenses will have in lens SR too. Sure, for handheld work the smaller FF retains significant advantages, but lens quality remains an issue with the smaller format at wider angles. I hope the Batis lenses will resolve this with the Sony line, but I have yet to use a wide on anything aside from a Leica M that offers the same quality as the 28-45mm DA.


QuoteOriginally posted by Simen1 Quote
I know. It was a rhetorical question to stevebrot that said the reason to buy 645 was "Better S/N ratio and DOF (you know the usual stuff)." Actually you don't get better DOF and S/N ratio on 645 because it doesn't have as large apertures available as FF will get. 645 also lacks shake reduction. So in my opinion the FF offering will have key advantages over 645. On the other side 645 will offer a different package with better resolution as the main selling point. Even f/1,4 lenses stopped down to f/2 cant resolve as much as the 645 on f/2,8. Or at resolution optimal apertures for that matter.

---------- Post added 06-27-2015 at 07:19 PM ----------



I think #1 and #2 is good guesses, but #3 might hold some genuine Tamron knowledge.


06-28-2015, 12:50 AM   #107
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QuoteOriginally posted by Rondec Quote
I don't really see how the decision between 36 and 42 megapixels makes a difference here. The difference in file size wouldn't be that much. The big question to me is whether or not Ricoh is planning to make this camera capable of really high quality video. If not, then there is no point to choosing the 42 megapixel sensor. It looks to me as though the things it benefits are faster read out speed and better video. I'm certainly not going to jump on the assumption that its noise levels will be significantly lower or dynamic range higher just because it has BSI. Maybe it will, but Samsung's 28 Megapixel APS-C sensor didn't perform any better than 24 megapixel Sony sensor, even though it had BSI, it just had faster frame rates and better video capability.
If Pentax launch with a standard, current-generation 36 mpx sensor then I'd guess that within six months Nikon will have surpassed it - in the eyes of the market - with a new-gen processor allied to a newer generation of Expeed. The mpx aren't the point. "New gen Sony sensor tech" is. Pentax might not have that. So Pentax would be left with semi-obsolete tech almost from the start - again in the eyes of the market and all those magazines and reviewers, etc. This would likely result in the sticker price of the Pentax FF offering falling quite fast, hardly good news for a project which is risky anyway. I mean, who other than a Pentaxian would be tempted to buy? So, and if they could, Pentax need to find some means of escaping an arms race with Nikon which they'll always lose. Nikon's buying power plus their Expeed line, which they make a lot of in their marketing, is like a big truck blocking the road in front of you.
06-28-2015, 02:51 AM - 1 Like   #108
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We shouldn't heap praise on the Sony 42MP until it has been released - and tested.

Some of the rumour sites suggest Sony has been having yield problems in their chip fab that have been complicating 42MP FF chip production.

36MP isn't that far away from 42MP, plus it has the stability and efficiency advantage of a longer period of manufacturing.
06-28-2015, 02:52 AM   #109
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QuoteOriginally posted by mecrox Quote
If Pentax launch with a standard, current-generation 36 mpx sensor then I'd guess that within six months Nikon will have surpassed it - in the eyes of the market - with a new-gen processor allied to a newer generation of Expeed. The mpx aren't the point. "New gen Sony sensor tech" is. Pentax might not have that. So Pentax would be left with semi-obsolete tech almost from the start - again in the eyes of the market and all those magazines and reviewers, etc. This would likely result in the sticker price of the Pentax FF offering falling quite fast, hardly good news for a project which is risky anyway. I mean, who other than a Pentaxian would be tempted to buy? So, and if they could, Pentax need to find some means of escaping an arms race with Nikon which they'll always lose. Nikon's buying power plus their Expeed line, which they make a lot of in their marketing, is like a big truck blocking the road in front of you.
Maybe.

I think the differentiation from Nikon will come on non-sensor things, particularly in body stabilization and things that offers. I do hope that Pentax actually makes a little effort to spruce up their video as well. It feels like the time is right for them to get a camera that can do 4K and that would need the 42 megapixel sensor, but at least in the past, video was just an after thought for them.

Either way, this is certainly going to be no sports camera. That hasn't been Pentax's strong point and it would be awhile before the glass is there to allow sports shooters to shoot Pentax (if they ever will).

06-28-2015, 06:35 AM   #110
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QuoteOriginally posted by mecrox Quote
Key question is whether Ricoh can source a digital processor good enough to handle the new sensor without bottlenecking its performance.
This ^^

A digital camera is a system, not just a sensor.
06-28-2015, 08:10 AM   #111
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well socionext still hasn't introduced a new soc. the M-7m milbeaut (k-3) is still the most recent processor. Some rumours the next soc which is 4k capable will be in the Nikon D5, but nothing definite. Maybe Pentax will switch to Sony...
06-28-2015, 10:09 AM   #112
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We should note that the 42MP sensor is capable of extremely fast readout, some 3.5x faster than the 36MP sensor.

Ricoh has been taking action/sports shooting performance very seriously lately. Considering that the 36MP sensor is limited to 4.7 fps, this would mean that the 42MP sensor can be fully read out at rates upwards of 15 fps. I don't think they can make the drive system or image processor this fast, but it does mean that high resolution and high speed aren't necessarily mutually exclusive. (The Milbeaut M-7M is limited to 12 fps @ 24MP, so Ricoh would need dual image processors or an all-new high-performance image processor to handle these data rates.)

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06-28-2015, 10:27 AM   #113
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Would a very fast readout time be of any help with pixel shift?

06-28-2015, 02:05 PM   #114
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Afaik for pixel shift the read out speed is an important factor. To my knowledge current technology can't read out a dslr sensor instantly (all pixels at the same time) hence it's happening in batches similar to mechanical shutter curtains that go from top to bottom.
06-28-2015, 02:30 PM   #115
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QuoteOriginally posted by wpvv Quote
Would a very fast readout time be of any help with pixel shift?
It would seem like it would, since if you could do 15 fps electronically, that would cut down significantly the amount of time necessary to make your four exposures. Currently it takes about a half second, I think, to do those four exposures.
06-28-2015, 06:21 PM   #116
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Making the buffer large enough is also going to be a challenge. There's a reason the Nikon D4 and D4S use a special memory card format called XQD. Even with a slower card, the worst-case buffer depth for lossless compressed 14-bit NEF is 53 shots on the D4 and 44 shots on the D4S (based on what is reported by the camera—r53 is displayed in the D4 viewfinder), so there's loads of RAM in the camera. (In my testing, the Pentax K-3 II has a worst-case buffer depth of 23 shots, although it does have 50% more pixels than the D4/D4S.)

Current SDHC/SDXC UHS-II cards can attain write speeds of up to 260 MB/s (Lexar Professional 2000x SDHC/SDXC UHS-II). XQD uses the PCIe interface (the same interface used for discrete graphics cards in PCs) and current cards can do 350 MB/s write and 400 MB/s read. The SDHC/SDXC UHS-II bus is limited to 312 MB/s, although I doubt this will be a genuine issue.

Ricoh absolutely needs to include UHS-II support in the upcoming full-frame camera in order to make the most of the 42MP Exmor R sensor.

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06-28-2015, 06:49 PM   #117
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QuoteOriginally posted by Rondec Quote
It would seem like it would, since if you could do 15 fps electronically, that would cut down significantly the amount of time necessary to make your four exposures. Currently it takes about a half second, I think, to do those four exposures.
But the shift/antishake mechanism isn't precisely moving up/down/left/right in a pattern either under 'normal' photographic use.. Would that really matter?
06-28-2015, 08:04 PM   #118
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The best news here is a Pentax factory service center in the US. Crappy service has deterred a number of people from buying into the system -- I've pretty much put Pentax on hold myself, as I apparently can't get my broken down 50-135 fixed in any reasonable time frame, at least according to numerous web reports.
06-28-2015, 08:09 PM - 1 Like   #119
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QuoteOriginally posted by bkpix Quote
The best news here is a Pentax factory service center in the US. Crappy service has deterred a number of people from buying into the system -- I've pretty much put Pentax on hold myself, as I apparently can't get my broken down 50-135 fixed in any reasonable time frame, at least according to numerous web reports.
Ahhh! I'm trying to get info on quoted price vs actual price as I have a 50-135 that also needs some work here https://www.pentaxforums.com/forums/173-general-photography/298145-precision-...ml#post3297847

But so far no info.. If we had an actual Ricoh staffed repair facility.. how nice would that be?
06-28-2015, 08:27 PM - 2 Likes   #120
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QuoteOriginally posted by VoiceOfReason Quote
We keep hearing that Ricoh is going to use the latest stuff, but then people here on the forum keep wanting Ricoh to use Sony and Nikon's castoffs, 3 year old tech. Why is that?
That is so the squealers and naysayers can squeal and naysay no matter which way they go! I thought everyone understood that by now!

Regards!
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