Digital Medium Format

fejker · 03-22-2009, 12:33 PM

Originally posted by falconeye

Because this is stated so many times, let me make my comment on this once in while...

Available DoF (at a given FoV) is only determined by the physical lens aperture in mm. So, I had a look at the available Pentax 645 prime lens lineup [source: pentax.de]:

35/3.5 -> 10 mm -> 20/2.0 -> FA 20/2.8, FA24/2.0
45/2.8 -> 16 mm -> 26/1.6 -> A 28/2, Sigma 30/1.4
75/2.8 -> 27 mm -> 43/1.6 -> FA 43/1.9, A50/1.2
120/4.0 Makro -> 30 mm -> 69/2.3 Makro -> FA77/1.8, FA50/2.8 Macro, FA100/2.8 Macro
150/2.8 -> 54 mm -> 87/1.6 -> FA85/1.4
200/4.0 -> 50 mm -> 116/2.3 -> FA100/2.8 Macro
300/4.0 -> 75 mm -> 173/2.3 -> FA135/2.8, FA200/2.8, A135/1.8
300/5.6
400/5.6 -> 71 mm -> 231/3.3 -> FA300/2.8, FA200/2.8

How to read:
#. 645 lens focal/aperture -> physical diameter -> FF lens/aperture with same DoF -> closest FF lens in Dimitrov's lens archive (dropping '*'-designations).
(Here, I assumed that FF is a 1.73x crop from MF.)

Where the corresponding FF glass actually has wider aperture, I've put it in boldface. I.e., the FA*85/1.4 or A50/1.2 offer DoF control unparalleled in the MF range.

Overall, medium format offers a slight advantage with respect to DoF control over FF. Much less significant than most people would believe w/o going through this exercise. And some lenses at the very short and very long end simply don't exist for MF. The advantages of MF are elsewhere (brighter VF, less noise, potentially much more headroom for digital crop, etc.). Therefore, I never would give up a "high-megapixel" option when going MF.

All true, but since Pentax is planing to offer MF instead of FF (for now at least) I think that the advantages over a crop sensor are far greater than FF compared to MF.

Anyway, when it comes to the price I think I wouldn't be able to afford such a system right now.

kcmadr · 03-23-2009, 09:35 PM

I looked in my crystal ball, and this is what I saw...

creampuff · 03-23-2009, 10:56 PM

Dump that stupid crystal ball.
This is what's coming... so everyone stop complaining and start saving up.

benjikan · 03-24-2009, 12:10 AM

F'ck and I am no longer sponsored by Pentax. I should have been a nice yes man and I would have received this baby when it comes out!!! Oh well "C'est La Vie..."

**Digitalis** · 03-24-2009, 12:45 AM

I recall reading from somewhere that they propose to put a 31Mp sensor in it made by specially Kodak and it's most likely to be a full frame 6X4.5 sensor knowing Kodak- just imagine the dynamic range at full 31MP 16bit raw files could produce....*drools*

I hope they keep the same metering system from the Pentax 645, that metering system was the equal of the Pentax LX in every way...it was extremely hard to fool, and it provided perfectly exposed shots in some of the most difficult situations

good thing I kept my 645 and 67 glass.

losecontrol · 03-24-2009, 01:01 AM

Originally posted by thibs

But 33MP only (speaking MF of course)
Latest Kodak MF CCD is 51MP
Kodak Image Sensor Solutions - Full Frame CCD

33MP only???

What are you going to print? A backround in a movie-scene??

Hasselblad said in an intervju that 39MP is enough to print any size you want (unlimited)!! There is no need in hell for a 51MP sensor.

So more then 40 is just a waiste....even if you can say: look guys, I have a 51Mp sensor....Im not impressed

losecontrol · 03-24-2009, 01:02 AM

Originally posted by kcmadr

I looked in my crystal ball, and this is what I saw...

what? one airplane?

**Digitalis** · 03-24-2009, 01:14 AM

Hasselblad marketing guys have said a lot of rubbish in the past... remember them saying that a 48mm square digital sensor was full frame when it was anything BUT full frame on medium format?

( my 100th post and i'm slamming hasselblad! give me my ARCbody back you B*stards!)

ogl · 03-24-2009, 01:24 AM

Design is very-very good. They've worked under camera from 2007.

thibs · 03-24-2009, 02:00 AM

Originally posted by Digitalis

I recall reading from somewhere that they propose to put a 31Mp sensor in it made by specially Kodak and it's most likely to be a full frame 6X4.5 sensor knowing Kodak- just imagine the dynamic range at full 31MP 16bit raw files could produce....*drools*

I hope they keep the same metering system from the Pentax 645, that metering system was the equal of the Pentax LX in every way...it was extremely hard to fool, and it provided perfectly exposed shots in some of the most difficult situations

good thing I kept my 645 and 67 glass.

No cropped but not much... about 1.3X AFAIR.

thibs · 03-24-2009, 02:18 AM

A couple things to notice:

* DFA645 have silver band rather than DA* gold band near focussing ring (yes purely cosmetics I know).

* 645D has Mirror lock up (button near the prism.

* 645 is clearly sealed (based on earlier pictures seen).

* The 645 format is in reality 56 × 41.5 mm which makes a diagonal of 6,97cm (http://en.wikipedia.org/wiki/120_film#Frame_sizes
Looking at Kodak sensors, the diagonal is between 5.52 and 6.13 cm (http://www.kodak.com/global/en/business/ISS/Products/Fullframe/index.jhtml?pq-path=14425

Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so.

If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm.

All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt).

Edit: Oh and the AF/MF switch on the DFA55 hints at SDM
EDit 2: no aperture ring on the DFA645 55mm.

**Rorschach** · 03-24-2009, 03:01 AM

*drool*

Have to brace myself in preparation for the sticker shocker though

falconeye · 03-24-2009, 04:08 AM

Originally posted by thibs

A couple things to notice:

Thanks for the detailed look!

If things turn out this way, the 645D would be at the lower end of possible specs. So maybe, it is closer to the 10k$ than 20k$?

**Digitalis** · 03-24-2009, 04:24 AM

Originally posted by thibs

A couple things to notice:

* DFA645 have silver band rather than DA* gold band near focussing ring (yes purely cosmetics I know).

* 645D has Mirror lock up (button near the prism.

* 645 is clearly sealed (based on earlier pictures seen).

* The 645 format is in reality 56 × 41.5 mm which makes a diagonal of 6,97cm (120 film - Wikipedia, the free encyclopedia
Looking at Kodak sensors, the diagonal is between 5.52 and 6.13 cm (http://www.kodak.com/global/en/business/ISS/Products/Fullframe/index.jhtml?pq-path=14425

Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so.

If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm.

All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt).

Edit: Oh and the AF/MF switch on the DFA55 hints at SDM
EDit 2: no aperture ring on the DFA645 55mm.

if all you say is accurate, then it's a weather sealed 31Mp medium format DSLR with SDM lenses...that's a recepie that should ruin Hasselblads day.

gazonk · 03-24-2009, 06:06 AM

Originally posted by thibs

Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so.

If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm.

All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt).

75mm is not quite "perfect normal" for the film 645 - that would be 70mm. A perfect normal for 45x30 would be a 54mm. 45x30 is 1.29x crop wrt. 56x41.5.

Quote:

Edit: Oh and the AF/MF switch on the DFA55 hints at SDM

Yay! I think the refined design of the camera (compared to previous prototypes) looks good.

03-22-2009, 12:33 PM	#16
fejker Inactive Account Join Date: Sep 2008 Location: Slovenia Photos: Gallery Posts: 258	Originally posted by falconeye Because this is stated so many times, let me make my comment on this once in while... Available DoF (at a given FoV) is only determined by the physical lens aperture in mm. So, I had a look at the available Pentax 645 prime lens lineup [source: pentax.de]: 35/3.5 -> 10 mm -> 20/2.0 -> FA 20/2.8, FA24/2.0 45/2.8 -> 16 mm -> 26/1.6 -> A 28/2, Sigma 30/1.4 75/2.8 -> 27 mm -> 43/1.6 -> FA 43/1.9, A50/1.2 120/4.0 Makro -> 30 mm -> 69/2.3 Makro -> FA77/1.8, FA50/2.8 Macro, FA100/2.8 Macro 150/2.8 -> 54 mm -> 87/1.6 -> FA85/1.4 200/4.0 -> 50 mm -> 116/2.3 -> FA100/2.8 Macro 300/4.0 -> 75 mm -> 173/2.3 -> FA135/2.8, FA200/2.8, A135/1.8 300/5.6 400/5.6 -> 71 mm -> 231/3.3 -> FA300/2.8, FA200/2.8 How to read: #. 645 lens focal/aperture -> physical diameter -> FF lens/aperture with same DoF -> closest FF lens in Dimitrov's lens archive (dropping ''-designations). (Here, I assumed that FF is a 1.73x crop from MF.)* Where the corresponding FF glass actually has wider aperture, I've put it in boldface. I.e., the FA85/1.4 or A50/1.2 offer DoF control unparalleled in the MF range. Overall, medium format offers a slight* advantage with respect to DoF control over FF. Much less significant than most people would believe w/o going through this exercise. And some lenses at the very short and very long end simply don't exist for MF. The advantages of MF are elsewhere (brighter VF, less noise, potentially much more headroom for digital crop, etc.). Therefore, I never would give up a "high-megapixel" option when going MF. All true, but since Pentax is planing to offer MF instead of FF (for now at least) I think that the advantages over a crop sensor are far greater than FF compared to MF. Anyway, when it comes to the price I think I wouldn't be able to afford such a system right now.

03-23-2009, 10:56 PM	#18
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	Coming soon... Dump that stupid crystal ball. This is what's coming... so everyone stop complaining and start saving up.

03-24-2009, 02:18 AM	#26
thibs Pentaxian Join Date: Jun 2007 Location: Belgium Photos: Albums Posts: 7,001	A couple things to notice: * DFA645 have silver band rather than DA* gold band near focussing ring (yes purely cosmetics I know). * 645D has Mirror lock up (button near the prism. * 645 is clearly sealed (based on earlier pictures seen). * The 645 format is in reality 56 × 41.5 mm which makes a diagonal of 6,97cm (http://en.wikipedia.org/wiki/120_film#Frame_sizes Looking at Kodak sensors, the diagonal is between 5.52 and 6.13 cm (http://www.kodak.com/global/en/business/ISS/Products/Fullframe/index.jhtml?pq-path=14425 Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so. If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm. All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt). Edit: Oh and the AF/MF switch on the DFA55 hints at SDM EDit 2: no aperture ring on the DFA645 55mm. Last edited by thibs; 03-24-2009 at 02:29 AM.

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03-23-2009, 09:35 PM	#17
kcmadr Veteran Member Join Date: Feb 2007 Location: Vancouver, BC Photos: Albums Posts: 614	I looked in my crystal ball, and this is what I saw...

03-24-2009, 12:10 AM	#19
benjikan Veteran Member Join Date: Jan 2007 Location: Paris, France Photos: Gallery Posts: 4,308	F'ck and I am no longer sponsored by Pentax. I should have been a nice yes man and I would have received this baby when it comes out!!! Oh well "C'est La Vie..."

03-24-2009, 12:45 AM	#20
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	I recall reading from somewhere that they propose to put a 31Mp sensor in it made by specially Kodak and it's most likely to be a full frame 6X4.5 sensor knowing Kodak- just imagine the dynamic range at full 31MP 16bit raw files could produce....drools I hope they keep the same metering system from the Pentax 645, that metering system was the equal of the Pentax LX in every way...it was extremely hard to fool, and it provided perfectly exposed shots in some of the most difficult situations good thing I kept my 645 and 67 glass.

03-24-2009, 01:01 AM	#21
losecontrol Veteran Member Join Date: Jan 2009 Location: Gnesta, Sweden Posts: 373	Originally posted by thibs But 33MP only (speaking MF of course) Latest Kodak MF CCD is 51MP Kodak Image Sensor Solutions - Full Frame CCD 33MP only??? What are you going to print? A backround in a movie-scene?? Hasselblad said in an intervju that 39MP is enough to print any size you want (unlimited)!! There is no need in hell for a 51MP sensor. So more then 40 is just a waiste....even if you can say: look guys, I have a 51Mp sensor....Im not impressed

03-24-2009, 01:02 AM	#22
losecontrol Veteran Member Join Date: Jan 2009 Location: Gnesta, Sweden Posts: 373	Originally posted by kcmadr I looked in my crystal ball, and this is what I saw... what? one airplane?

03-24-2009, 01:14 AM	#23
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Hasselblad marketing guys have said a lot of rubbish in the past... remember them saying that a 48mm square digital sensor was full frame when it was anything BUT full frame on medium format? ( my 100th post and i'm slamming hasselblad! give me my ARCbody back you B*stards!)

03-24-2009, 01:24 AM	#24
ogl Banned Join Date: Dec 2007 Location: Sankt Peterburg Photos: Gallery \| Albums Posts: 8,382	Design is very-very good. They've worked under camera from 2007.

03-24-2009, 02:00 AM	#25
thibs Pentaxian Join Date: Jun 2007 Location: Belgium Photos: Albums Posts: 7,001	Originally posted by Digitalis I recall reading from somewhere that they propose to put a 31Mp sensor in it made by specially Kodak and it's most likely to be a full frame 6X4.5 sensor knowing Kodak- just imagine the dynamic range at full 31MP 16bit raw files could produce....drools I hope they keep the same metering system from the Pentax 645, that metering system was the equal of the Pentax LX in every way...it was extremely hard to fool, and it provided perfectly exposed shots in some of the most difficult situations good thing I kept my 645 and 67 glass. No cropped but not much... about 1.3X AFAIR.

03-24-2009, 03:01 AM	#27
Rorschach Site Supporter Join Date: Nov 2007 Location: Kuusamo, Finland Photos: Gallery Posts: 652	drool Have to brace myself in preparation for the sticker shocker though

03-24-2009, 04:08 AM	#28
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by thibs A couple things to notice: Thanks for the detailed look! If things turn out this way, the 645D would be at the lower end of possible specs. So maybe, it is closer to the 10k$ than 20k$?

03-24-2009, 04:24 AM	#29
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by thibs A couple things to notice: * DFA645 have silver band rather than DA* gold band near focussing ring (yes purely cosmetics I know). * 645D has Mirror lock up (button near the prism. * 645 is clearly sealed (based on earlier pictures seen). * The 645 format is in reality 56 × 41.5 mm which makes a diagonal of 6,97cm (120 film - Wikipedia, the free encyclopedia Looking at Kodak sensors, the diagonal is between 5.52 and 6.13 cm (http://www.kodak.com/global/en/business/ISS/Products/Fullframe/index.jhtml?pq-path=14425 Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so. If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm. All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt). Edit: Oh and the AF/MF switch on the DFA55 hints at SDM EDit 2: no aperture ring on the DFA645 55mm. if all you say is accurate, then it's a weather sealed 31Mp medium format DSLR with SDM lenses...that's a recepie that should ruin Hasselblads day.

03-24-2009, 06:06 AM	#30
gazonk Pentaxian Join Date: Feb 2009 Location: Oslo area, Norway Photos: Gallery \| Albums Posts: 3,746	Originally posted by thibs Standard lens for film 645 is 75mm. If the standard now becomes 55mm, the crop is 1.3x or 5,36cm. Corresponding available sensors is 31.6MP. Furthermore, Pentax said sensor of more than 30MP, if they knew they'd go for 50MP they'd say so. If they decide to go for higher MP sensor from Kodak, the diagonal would be 6,13 cm and normal lens would be 65mm. All this only if the crop maintain the same aspect as the orgininal 645 format (which I doubt). 75mm is not quite "perfect normal" for the film 645 - that would be 70mm. A perfect normal for 45x30 would be a 54mm. 45x30 is 1.29x crop wrt. 56x41.5. Quote: Edit: Oh and the AF/MF switch on the DFA55 hints at SDM Yay! I think the refined design of the camera (compared to previous prototypes) looks good.