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02-07-2008, 11:36 AM   #16
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I am just curious

A number of posts suggests that a 645D, even with 24x36mm sensor (aka 35mm FF full-frame), would be a great thing to have, esp. if well under $10,000.

A number of other posts have clarified that there would be no technical point in having this, as it seems to be an agreed fact that a fully functional 645 lens K-mount adaptor plus a standard 35mm FF Pentax DSLR would give exactly the same at a lower price point.

So, the wish to have a 645D with whatever sensor must mainly be an emotional one.

So I am curious: Which emotion exactly is it such a camera would raise?

02-07-2008, 12:47 PM   #17
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The thing is, MF isn't only about the size of the image area - not in the resolution sense - but about the focal length / fov equation. So also the APS / Full frame 35mm is at least in part about the focal length.

After all, a 35mm lens on an APS sensor does NOT give you the same photograph as a 50mm on a full frame. So also, the 70-80 mmm lens on a MF gives you a different photograph. I happen to prefer the MF focal length/fov ratio. There's something about a slightly longer lens being normal.

It just seems to me that a full frame 35 and a 'smaller than' 4,5x6 sensor are pretty close in overall size. In part, my question was economic - does a company have to produce two such parts simply to have two formats - 35mm and mf?

There is cool factor & uniqueness, as C&N may have FF 35mm but they don't have a pygmy MF digital! But for me at least, a sensor that's too small negates one of the major attractions of MF, for me.
02-07-2008, 02:16 PM   #18
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It is the size of the viewfinder

QuoteOriginally posted by falconeye Quote
So, the wish to have a 645D with whatever sensor must mainly be an emotional one.

So I am curious: Which emotion exactly is it such a camera would raise?
Go out and look through your old film SLR or even better get hold of a MF SLR and check out the view through the viewfinder. That is it! As easy as that. Just a pleasure to work with.

Torge
02-07-2008, 03:26 PM   #19
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QuoteOriginally posted by torge Quote
Go out and look through your old film SLR or even better get hold of a MF SLR and check out the view through the viewfinder. That is it! As easy as that. Just a pleasure to work with.
Good point! I easily imagine this. But this would be technical reason.

Then again, a digital MF SLR must not be cropped down to a 35mm sensor as this would degrade the VF to a 35mm one as well.

And then again, because there is no technical reason for a 24x36mm 645D, what are its emotional benefits?

02-07-2008, 03:43 PM   #20
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QuoteOriginally posted by falconeye Quote
Then again, a digital MF SLR must not be cropped down to a 35mm sensor as this would degrade the VF to a 35mm one as well.

And then again, because there is no technical reason for a 24x36mm 645D, what are its emotional benefits?
O, I totally agree, that 24x36mm sensor in a 645D body for the sake of being able to use old 35mm lenses that require a much smaller register distance is just rubbish!
Make the sensor as big as affordable! Aspect ratio is really not that important, they might even go for the sweet spot determined by silicon wafer thingi production process. Could be square or 33x44mm as proposed initially, based on the Kodak sensors.

With K20D Technology that would give something close to 60MP files and there might be room to maybe come up with something like 45MP with much improved ISO capabilites.
How sweet would that be? Still twice as much MPs as the FF announced by Sony, but with likely much better ISO performance still. On top of that, I would have all my lenses already in place, apart from a real wide angle due the changed crop sensor.

Torge
02-08-2008, 03:25 AM   #21
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QuoteOriginally posted by Nesster Quote
It just seems to me that a full frame 35 and a 'smaller than' 4,5x6 sensor are pretty close in overall size. In part, my question was economic - does a company have to produce two such parts simply to have two formats - 35mm and mf?
AFAIR the projected Kodak sensor was 48x36 in size which means... two times as big as a "FF" sensor. So you can choose Twice pixels, or pixels two times as big or a nice middle point between those two
02-08-2008, 07:21 AM   #22
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While i see no advantage in a camera with 645 body and 24x36 sensor, I think it could be interesting, for pros owning 645 gear, a 24x36 (or something more, like 30x40) camera with Eos1Ds/D3 form-factor and 645bayonet.

After all, the standard lens for the 645Digital that was in the roadmap was a 55mm, and that is the standard lenght for a sensor slightly bigger than 24x36, I guess.
02-09-2008, 07:33 AM   #23
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There could be another advantage with using a smaller sensor within the coverage of the 645 lenses: the sensor could be made to shift and tilt, giving the camera at least part of the image-control of a view camera. And that would be with all lenses, not just specialized ones.

02-09-2008, 07:42 AM   #24
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Hi Torge

I was just kinda thinking out loud when you said:

QuoteQuote:
With K20D Technology that would give something close to 60MP files
....what kind of buffer would you require to store 60MP files at 5 fps.....LOL !!

Best regards
Richard

Last edited by Confused; 02-09-2008 at 09:44 AM.
02-09-2008, 10:54 AM   #25
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QuoteOriginally posted by Confused Quote
Hi Torge

I was just kinda thinking out loud when you said:

....what kind of buffer would you require to store 60MP files at 5 fps.....LOL !!

Best regards
Richard
... well, I don't think a camera like the 645D with >40MP would be designed to win the fps race! It would be a studio camera as the 645 film series was and hopefully be rugged enough (weathersealed, etc) to be taken into the field as the ultimate landscape photographers tool!

Might have to sell my A* 135mm and a couple other lenses if this beast ever materializes.

Cheers,
Torge
02-09-2008, 10:59 AM   #26
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Hi falconeye

Oh dear G*d, I experienced this dreadful sinking feeling in the pit of my stomach when you said:

QuoteQuote:
A number of posts suggests that a 645D, even with 24x36mm sensor (aka 35mm FF full-frame), would be a great thing to have
It was that "even with 24x36mm sensor" which did it ! I'll probably get shot down in flames yet again, but I'll say it anyway as soon as I've donned my fire-proof suit.
It's widely accepted that 10" x 8" provides superior image quality to 5" x 4", which in turn provides superior image quality to
60 x 45mm which in turn provides superior image quality to 36 x 24mm ad infinitum until we reach APS-C etc.
As far as I'm concerned, if the sensor size isn't physically 60mm x 45mm (forget the number of pixels for the moment) the camera doesn't qualify as MEDIUM FORMAT. Period ! That applies to Phase One and the rest of them put together.
The thought of Pentax (or anyone else for that matter) attempting to describe a DSLR with a 48 x 36mm sensor as Medium Format deserves to have their entire production run laid neatly out in front of a heavy steam-roller & be crushed into infinitesimal pieces !
Either that, or the chaps from the Trades Description bureau need to have a serious word with those responsible in the marketing department ! If I went into a Bentley showroom to order the latest V12 model, I would be distinctly upset if it was delivered to my doorstep missing 4 cylinders (V8) ! This is the equivalent of the 35mm full-frame versus APS-C argument raising it's head again !
I once spent a very amusing hour a few years ago trying out the latest so-called 'Medium Format' Mamiya digital camera back at a well-respected London store and was encouraged to try this out in conjunction with my Mamiya 50mm F4.0 perspective correction (shift) lens that I had taken along for the day. I clearly remember attaching the lens to the body and then mounting it onto a sturdy tripod. Having taken this outfit upstairs to street level, I proceeded to take some photographs of the nearby buildings with the shift lens extended fully upwards. You can probably imagine my subsequent surprise after downloading these photos onto the shop's computer, only to discover that the top third of the images were nowhere to be seen !
"Ah" said the store assistant, "I'm afraid that's because the sensor is not yet full frame".
The body alone was priced somewhere around 12,500.00 / $24,000.00, so I gently took him to one side and said:
"Please give me a call when they eventually come up with a proper full-sized MF sensor".....
Well, it hasn't happened yet, but I still live in hope..........LOL !

Best regards
Richard

Last edited by Confused; 02-11-2008 at 01:35 PM.
02-09-2008, 06:53 PM   #27
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QuoteOriginally posted by Confused Quote
Hi falconeye
Oh dear G*d, I experienced this dreadful sinking feeling in the pit of my stomach when you said: It was that "even with 24x36mm sensor" which did it !
Hi Richard,

thank You for sharing your feelings. I do feel exactly the same which is why I was asking the question.

After your post I start thinking that there actually isn't anybody left anymore wanting a 24x36mm sensor 645D. That would be the best thing to happen.
02-09-2008, 07:09 PM   #28
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QuoteOriginally posted by Nesster Quote
Just throwing the thought out there - why not combine two speculations, that of the 35mm FF sensor, and the MF camera.

A 35mm full size sensor (in a different aspect ratio) is roughly equivalent to an 'APS' size medium format sensor. So why not bring out such a camera?

(I know, I know, there's more demand and equipment out there for 35mm)
A full frame sensor can only pack around 25mp at present, although Samsung's 14mp sensor, when doubled up to full frame in size, can hold around 28-29mp. That may well work for an entry level medium format DSLR, since the top of the line medium format sensor is only around 39mp. Medium format sensor resolution may well rise above 39mp, so if Samsung and Pentax are serious about a medium format sensor that is basically the same as a full frame sensor, they should act quickly. Alternatively, Pentax may use Sony's 24mp sensor in its 645D.
02-10-2008, 02:11 AM   #29
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QuoteOriginally posted by Anastigmat Quote
Alternatively, Pentax may use Sony's 24mp sensor in its 645D.
Here we go again ...
02-15-2008, 06:04 AM   #30
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QuoteOriginally posted by thibs Quote
AFAIR the projected Kodak sensor was 48x36 in size which means... two times as big as a "FF" sensor. So you can choose Twice pixels, or pixels two times as big or a nice middle point between those two
I don't think it was that big (48x36, a 1.1 crop)... I'm fairly certain that it was a bit more of a compromise than that... 44x33 (1.3 crop). The 31.6 KAF-31600 from Kodak, if memory serves. Though I imagine that if it is still in development, they might be looking at something from Samsung or a CMOS sensor from elsewhere, and with a higher resolution. That or they're still using the Kodak and trying to target for about $5000 SRP.

As for a "full-frame" 645D, I can't imagine it would be anything less than 36x27 (1.5/1.6 crop), and at any rate certainly in a 4:3 aspect ratio. I'd say less than that, in either dimension, would be madness.

Will
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