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04-25-2012, 05:27 AM   #61
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QuoteOriginally posted by Pål Jensen Quote
Spot on! However, they need to adress the wide angle issue for a cropped 645 sensor. At over 1 kilograms and $5000 the 25mm is the most pointless lens Pentax have ever made and make the 645 system almost single handedly out of reach of most who actually want to shoot reasonably wide. An FF 645 sensor would probably not have costed $5000 dollar over the current cropped one and you would have gotten better image quality in the bargain! Not to mention the weigth savings of not having to carry a 1+ kg wide angle lens...
Also, if they wanto the 645D be their fullframe formar, they need to adress another point, that is high aperture lenses. Being the 33x44 not so much larger than 36x24, they need lenses with larger aperture, since the formar doen't compensate for greater DOF control. Not that they need f/1,4 lenses, but some F2,8 are needed. Also, higher ISO are needed, too.

04-25-2012, 05:51 AM   #62
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the 645D crop sensor has 68% more real estate than a FF sensor eurostar. It allows a larger pixel pitch with more mp than say the D800. Moving to a FF 645 sensor would increase that dramatically. a FF 645 sensor (56x41.5) is 2.69 x the size of a FF 35mm sensor (so like the difference between MFT and FF) Move to that sensor and there is fare less need for faster lenses than 2.8
For portraits shooting a 150 at 7 feet @ 2.8 a 645 will have about 2 inches in focus (so a head/ shoulders portrait)
on a FF 85 @ 1.4 @ 7 feet there will be the same DOF with a slightly wider FOV

Faster than 2.8 lenses in medium format are of little use for the most part because the DOF get's so thin it becomes unusable. for the crop sensor the 645D uses I would say a 2.0 would be usable (though it would be a monster lens if it was designed to sill a ff 645 sensor)
As for the complaints about the 25mm lens prices I've seen, it's wholly relative. 645 lenses are never cheap., first they have a much smaller market so costs are spread across fewer buyers, second there is a lot more high quality glass cost involved as they mus be larger to cover the 645 image circle
$5000 isn't out of line for the 25 if you ask me
the Hassy 28 f4.0 is 5300 and weighs close to 2 pounds (850grams)
the mamiya 28 f4.5 is also $5000 and weighs 886 grams
this wide a lens is relatively new to the MF world
Previously wider than 35 was rare (and usually a fisheye)

Looking at Medium format form the perspective of FF 35mm has never worked. In film days the same sort of disparity between systems existed.
04-25-2012, 07:05 AM   #63
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QuoteOriginally posted by Pål Jensen Quote
Spot on! However, they need to adress the wide angle issue for a cropped 645 sensor. At over 1 kilograms and $5000 the 25mm is the most pointless lens Pentax have ever made and make the 645 system almost single handedly out of reach of most who actually want to shoot reasonably wide. An FF 645 sensor would probably not have costed $5000 dollar over the current cropped one and you would have gotten better image quality in the bargain! Not to mention the weigth savings of not having to carry a 1+ kg wide angle lens...
Very good points! On FF 645 one could use the FA645 35mm lens instead, which weighs just 560g and costs $2000 (Norwegian shop price minus sales tax).
04-25-2012, 07:34 AM   #64
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it's my favorite gallery of MF photos...

04-25-2012, 07:44 AM   #65
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QuoteOriginally posted by eddie1960 Quote
the 645D crop sensor has 68% more real estate than a FF sensor eurostar. It allows a larger pixel pitch with more mp than say the D800. Moving to a FF 645 sensor would increase that dramatically. a FF 645 sensor (56x41.5) is 2.69 x the size of a FF 35mm sensor (so like the difference between MFT and FF) Move to that sensor and there is fare less need for faster lenses than 2.8
For portraits shooting a 150 at 7 feet @ 2.8 a 645 will have about 2 inches in focus (so a head/ shoulders portrait)
on a FF 85 @ 1.4 @ 7 feet there will be the same DOF with a slightly wider FOV

Faster than 2.8 lenses in medium format are of little use for the most part because the DOF get's so thin it becomes unusable. for the crop sensor the 645D uses I would say a 2.0 would be usable (though it would be a monster lens if it was designed to sill a ff 645 sensor)
As for the complaints about the 25mm lens prices I've seen, it's wholly relative. 645 lenses are never cheap., first they have a much smaller market so costs are spread across fewer buyers, second there is a lot more high quality glass cost involved as they mus be larger to cover the 645 image circle
$5000 isn't out of line for the 25 if you ask me
the Hassy 28 f4.0 is 5300 and weighs close to 2 pounds (850grams)
the mamiya 28 f4.5 is also $5000 and weighs 886 grams
this wide a lens is relatively new to the MF world
Previously wider than 35 was rare (and usually a fisheye)

Looking at Medium format form the perspective of FF 35mm has never worked. In film days the same sort of disparity between systems existed.
My point is that if Pentax wants the 44x33 format to be their fullframe, to compete not with Hasselblad and Phase One, but with Canon and Nikon, even taking into account the much larger frame, still you need to be on a much similar approach, that is much more evident when you think that the normal for 645D is a 55 mm lens and a portrait lens is 90mm. So I don't ask for 1,2 or 1,4 aperture, but some f2,8 ones are needed, if you want compete directly on the ceremonies and portrait and food fields, and not just on landscape. Obviously I am not talking about sport, wildlife and reportage, because I think APS-C will devour those in the next few years.

Obviously if they have no intentino of competing, and just sell a middle way camera between full frame and MF backs, they can stay where they are now, with no need to acting differently, and still having a big piece of a small market.
04-25-2012, 08:05 AM   #66
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there is the 150 2.8 for portraits but it is a little long on the crop sensor (perfect for a FF sensor) so the real issue is are they going to stick cropped or move to a FF sensor. Right now all the sub $30000 stuff is cropped.FF starts at a high price 30 + just for a back. Thing is when Pentax launched the 645D they broke a lot of price barriers for the MP (even a 22 mp system was close to $20 grand at the time). If they can get the right sensor (and I believe the former Kodak now has a FF CCD now) they could impact the market the same at $15000 or so for an updated 645D (with faster processors and better memory card slots and a few other tweaks) and drop the 645D to an entry level of say $7500 and have a 2 body setup that maximizes lens value and sales. It wouldn't consume massive amounts of production time but could be very profitable if they can get the sensor at the right price (the original sensor cost around $3000 at release - less now I am sure- If they could source a FF alternative for $6000 I think a $15000 body is doable - and would really challenge the other 3)
04-25-2012, 09:24 AM   #67
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QuoteOriginally posted by eddie1960 Quote
As for the complaints about the 25mm lens prices I've seen, it's wholly relative. 645 lenses are never cheap., first they have a much smaller market so costs are spread across fewer buyers, second there is a lot more high quality glass cost involved as they mus be larger to cover the 645 image circle
$5000 isn't out of line for the 25 if you ask me
.
The point is that the 25mm owns its existence to the fact that the 645D has a cropped sensor and hence, a wider lens than the 35mm was needed in the line-up. There was no 25mm for the film 645 system and probably very few missed one.
I'd rather have an FF 645D than a 25mm lens....
The 645 system was actually marketed and designed as an alternative to 35mm. However, with a 1,4kg camera and a 1kg wideangle lens + the other lenses you'll need, the 645 system has gone from portable to something that is not.
Pentax main competition is not not Hasselblad and the like as they don't sell to anyone anyway, but Nikon and Canon FF....
04-25-2012, 09:29 AM   #68
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QuoteOriginally posted by gazonk Quote
Very good points! On FF 645 one could use the FA645 35mm lens instead, which weighs just 560g and costs $2000 (Norwegian shop price minus sales tax).
..not to mention that the 33-55, which is many lenses in one, weights only 500grams.....

04-25-2012, 09:32 AM   #69
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QuoteOriginally posted by eurostar Quote
My point is that if Pentax wants the 44x33 format to be their fullframe, to compete not with Hasselblad and Phase One, but with Canon and Nikon, even taking into account the much larger frame, still you need to be on a much similar approach, that is much more evident when you think that the normal for 645D is a 55 mm lens and a portrait lens is 90mm. So I don't ask for 1,2 or 1,4 aperture, but some f2,8 ones are needed, if you want compete directly on the ceremonies and portrait and food fields, and not just on landscape. Obviously I am not talking about sport, wildlife and reportage, because I think APS-C will devour those in the next few years..
I've never heard anyone that complains about not getting thin enough DOF with medium format. Besides the thin DOF argument is rather tedious as 99.99% of all photography is about getting enough DOF, and that is some...
04-25-2012, 09:46 AM   #70
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QuoteOriginally posted by Pål Jensen Quote
The point is that the 25mm owns its existence to the fact that the 645D has a cropped sensor and hence, a wider lens than the 35mm was needed in the line-up. There was no 25mm for the film 645 system and probably very few missed one.
I'd rather have an FF 645D than a 25mm lens....
The 645 system was actually marketed and designed as an alternative to 35mm. However, with a 1,4kg camera and a 1kg wideangle lens + the other lenses you'll need, the 645 system has gone from portable to something that is not.
Pentax main competition is not not Hasselblad and the like as they don't sell to anyone anyway, but Nikon and Canon FF....
True the 25 is in existence due to the crop. They also endeavored to make it a FF lens (without success for the most part so they made it a crop design to get it out, though I'm not sure much of the design changed more the idea it is a good crop lens. given the widest from the others aren't even as wide as this lens (28 versus 25) but they are FF AFAIK it may have been better to target an asph 30 that was sharp edge to edge on FF looking to the future

My main point was however hat it is not priced unrealistically versus its comp set which is MF not 35MM. it's really only the introduction of the D800 that even makes it an issue though. An update that breaks ground as an affordable FF 645 (and therefore 60-80MP assumed) addresses the issue. Keeping the 645D around as a low cost (relative to the market) entry makes sense as long as they can get the sensors (so a few more years I bet)
MF was never a big market compared to 35MM. In digital it's even more marginalized because some of the 35MM is truly astounding. But there is a client subset.
You may think hassy/Mamiya/Phase don't sell much but i think they actually sell a fair bit within their subset of the market. As an example within a 20 minute walk of my house downtown Toronto I can get to 4 phase/mamiya dealers and 3 hassy ones and 2 Pentax MF ones and 1 Leica S2 dealer.
But we are a large market with a vibrant Advertising photo industry so maybe I get a warped view.

A agree they need to address the launch of a camera like the D800 but I think a Sensor upgrade is a more viable answer. the MF cameras will never compete with the versatility of the Niko canon Systems (or for that matter even the Sony and Pentax ones)

For me if I want to shoot MF look I will stick to MF film. I just can't justify the digital cost because i don't sell into the market that would pay for it.
04-25-2012, 01:48 PM   #71
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QuoteOriginally posted by Pål Jensen Quote
I've never heard anyone that complains about not getting thin enough DOF with medium format. Besides the thin DOF argument is rather tedious as 99.99% of all photography is about getting enough DOF, and that is some...
I have never used 33x44 mm, so I don't know. I see that the standard lens is 55mm, that was the same on the Spotmatic, so I guess the behaviour is somehow different form film MF. Where on 645 4 suffice, while on 35mm I'd want 2 or larger, I guess an intermediate 2,8 for 44x33 would be needed. But, as I said, I have never even saw a 645D in life, so it's just supposition on my part.
04-25-2012, 01:52 PM   #72
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QuoteOriginally posted by eurostar Quote
I see that the standard lens is 55mm, that was the same on the Spotmatic, so I guess the behaviour is somehow different form film MF.
55mm is the diagonal of the sensor, so it's the same as a 43mm lens on 35mm film. The 75mm lens is actually closer to using a 55mm on the Spotmatic (it corresponds to 59mm).
04-25-2012, 02:03 PM   #73
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I'll throw out some numbers here because that's about all I'm good for right now. Let's compare AOV+DOF equivalences between formats. I'll use these frame dimensions: 135/FF (36x24mm); nominal APS-C (25.1x16.7mm); my K20D (23.4x15.6mm); 645D (44x33mm); 645/FF (56x41.5mm). Just for ducks, I'll include 6x9/FF (~84x56mm). If we divide the focal length and max aperture of a basic standard prime (50/2 on 135/FF) by format-faktors (ratios of format diagonals), we get this:

135/FF: 50/2
APS-C: 35/1.4
K20D: 32/1.3
645D: 63/2.5
645FF: 81/3.2
6x9/FF: 117/4.7

Those optics shooting from the same position will produce the same image. I am insufficiently caffeinated to draw any conclusions, other than that fast-enough lenses for larger formats should NOT have impossibly thin DOF. Discuss.
04-25-2012, 02:13 PM   #74
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QuoteOriginally posted by RioRico Quote
I'll throw out some numbers here because that's about all I'm good for right now. Let's compare AOV+DOF equivalences between formats. I'll use these frame dimensions: 135/FF (36x24mm); nominal APS-C (25.1x16.7mm); my K20D (23.4x15.6mm); 645D (44x33mm); 645/FF (56x41.5mm). Just for ducks, I'll include 6x9/FF (~84x56mm). If we divide the focal length and max aperture of a basic standard prime (50/2 on 135/FF) by format-faktors (ratios of format diagonals), we get this:

135/FF: 50/2
APS-C: 35/1.4
K20D: 32/1.3
645D: 63/2.5
645FF: 81/3.2
6x9/FF: 117/4.7
Or, the other way around:

The FA645 75mm/2.8 on 645FF corresponds roughly to a 46mm/1.7 on 135FF, or a 31mm/1.15 on APS-C.
The DFA645 55mm/2.8 on 645D corresponds roughly to a 43mm/2.2 on 135FF, or a 28mm/1.4 on APS-C.
04-26-2012, 02:55 AM   #75
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QuoteOriginally posted by gazonk Quote
Or, the other way around:

The FA645 75mm/2.8 on 645FF corresponds roughly to a 46mm/1.7 on 135FF, or a 31mm/1.15 on APS-C.
The DFA645 55mm/2.8 on 645D corresponds roughly to a 43mm/2.2 on 135FF, or a 28mm/1.4 on APS-C.
It seems to me that my point about the need of at least F/2,8 lenses on 645D to have narrow DOF like on 24x36 has some... depth...
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