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09-14-2020, 08:16 AM - 1 Like   #1
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Digital 67

I’m sure this has been mused before, but why did most film companies abandon the 6x7 format when moving to digital? Contax and Pentax are pretty much the main culprits. This also kind of helps me, because I’m torn between saving for a 645Z or a 67 (when I get consistently good film shots and development). When you bump up to MF, those are the two most accessible companies. Yes, Hasselblad makes extremely fine digital bodies, but the mainstream consumer doesn’t want to sell their first born and donate a kidney for a camera. With all the benefits of a larger sensor size, it would seem that 6x7 would offer the greatest benefit, in terms of MF, when compared to 6x4.5. Looking at the size of the film it clearly shows that 6x7 is almost 4x as large as 35mm, while IMO, 6x4.5 appears to only be 2-2.5x’s larger. So, yeah, why did pretty much everybody abandon the size for 6/4.5?

09-14-2020, 08:30 AM - 1 Like   #2
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QuoteOriginally posted by bikehead90 Quote
but why did most film companies abandon the 6x7 format when moving to digital?
Cost of sensors.
Same reason why APS-C was adopted as a standard over a 35mm equivalent sensor on the advent of the digital camera boom.
09-14-2020, 08:35 AM - 2 Likes   #3
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I'm sure someone more learned than I will chime in to give fuller details, but in a nutshell, sensor cost. A 6x7 digital sensor would make for a very pricey camera.
The digital 645 uses a sensor smaller than the traditional 645 film frame, again for cost reasons. Going forward it's conceivable the sensor cost will continue to come
down and we may one day get a FF 645 and even larger digital sensors at a cost equal to a used car rather than a house mortgage.
09-14-2020, 08:36 AM - 1 Like   #4
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Might also add something towards this:
I believe back in the day, large format and medium format was used to make 1:1 large prints.
I believe it was Leica with their rangefinders that really made the 35mm a standard film size with the intent to enlarge prints.
Now with digital cameras, increasing megapixel count, and increased tech like AI and the noise reducing accelerator units - really makes those larger formats seem expensive and unnecessary.
imo, as a happy aps-c shooter, the above is how I even perceive a full frame 35mm camera..

09-14-2020, 08:43 AM - 9 Likes   #5
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Hi,

Well, first you have to make a chip that large. Not easy and certainly not cheap. That means a circular wafer (the slice of silicon off the 'salami' log) large enough to accommodate that large a die (what we call the chips before they are cut out of the wafer and packaged).

Now, normally, in any process, we print (lithography is used to put the pieces of the chip onto the die) several chips onto a wafer. This way, if one or two come out bad, we have other good ones to add the cost of the bad ones to. With really large chips, we get one die per wafer. That means the entire wafer cost goes into the chip. When one comes out bad, that cost has to add onto the good ones, but now that really adds up.

I can also see making a 6x7 chip if one uses more than one die and marries them into a single chip. This was done by Kodak with the chip used in the Pentax 645D. There are more costs associated with this, and it is used when there simply isn't a wafer technology around to make one larger chip with. It is a real trade-off which way winds up costing less.

The bottom line is, what will the market bear for the cost of such a chip? I estimate such to be $30k just for the part.

I recall spending $30k per 1 megapixel chip from Kodak in 1984. This was the first of the IBM board line vision systems and I used six chips and had to make my own cameras and processing software to allow these to image the large boards. This wound up leading to a significant cost savings on the board line, but wouldn't have been of any interest to more normal photography. Kodak didn't get the chip costs down to where they could sell a DSLR using one such chip until 1989.

Anyway, the bottom line is the Crop 645 chips have reached a point where they are low cost enough to be doing well with. The 50 MP of the P645Z and the Fuji 50 series, and then the 100 MP of the Fuji 100. I expect Pentax to use the 100 MP next, although they could also use the 150 MP 645 'full frame' chip for a more costly unit. I expect the 100 would be $10k and the 150 $15k.

Stan
09-14-2020, 09:23 AM   #6
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QuoteOriginally posted by wa2kqy Quote
Hi,

Well, first you have to make a chip that large. Not easy and certainly not cheap. That means a circular wafer (the slice of silicon off the 'salami' log) large enough to accommodate that large a die (what we call the chips before they are cut out of the wafer and packaged).

Now, normally, in any process, we print (lithography is used to put the pieces of the chip onto the die) several chips onto a wafer. This way, if one or two come out bad, we have other good ones to add the cost of the bad ones to. With really large chips, we get one die per wafer. That means the entire wafer cost goes into the chip. When one comes out bad, that cost has to add onto the good ones, but now that really adds up.

I can also see making a 6x7 chip if one uses more than one die and marries them into a single chip. This was done by Kodak with the chip used in the Pentax 645D. There are more costs associated with this, and it is used when there simply isn't a wafer technology around to make one larger chip with. It is a real trade-off which way winds up costing less.

The bottom line is, what will the market bear for the cost of such a chip? I estimate such to be $30k just for the part.

I recall spending $30k per 1 megapixel chip from Kodak in 1984. This was the first of the IBM board line vision systems and I used six chips and had to make my own cameras and processing software to allow these to image the large boards. This wound up leading to a significant cost savings on the board line, but wouldn't have been of any interest to more normal photography. Kodak didn't get the chip costs down to where they could sell a DSLR using one such chip until 1989.

Anyway, the bottom line is the Crop 645 chips have reached a point where they are low cost enough to be doing well with. The 50 MP of the P645Z and the Fuji 50 series, and then the 100 MP of the Fuji 100. I expect Pentax to use the 100 MP next, although they could also use the 150 MP 645 'full frame' chip for a more costly unit. I expect the 100 would be $10k and the 150 $15k.

Stan
Do you think a 6x7 chip could be affordable for pro cameras in the next 20 years? Are there any sensors available larger than FF 645?
Thanks,
barondla

Just thinking, how big is a wafer? How about using the whole thing for a large format round sensor? Wow!

Last edited by barondla; 09-14-2020 at 09:25 AM. Reason: clarity
09-14-2020, 09:38 AM - 1 Like   #7
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There are a bunch of Phase One (among others) 6x4.5 backs... But they run into the tens of thousands of euros. I can't imagine a digital 6x7 back going for less than a fortune.

09-14-2020, 09:52 AM - 1 Like   #8
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QuoteOriginally posted by bikehead90 Quote
I’m sure this has been mused before, but why did most film companies abandon the 6x7 format when moving to digital?
One can shoot that format in digital today, but it requires a scanning back and a computer to manage the data flow. The biggest issue is not sensor size per se, but the data buffering/management. It takes forever to charge and flush the buffers, hence the scanning back solution.


Steve
09-14-2020, 06:43 PM - 1 Like   #9
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LargeSense proved that 8x10 sensors are possible for ~90k; they're working on a higher res 4x5 for $65k. So although they are very expensive by 35mm standards, I don't see why 6x7 wouldn't be possible for 30-40k or so, in the price range of some existing high end 645 MF systems.

Pentax may no longer be the only player in "affordable MF" but there may be an opportunity for some company to "one up" everyone with a 6x7 at the same price as the 645 systems.
09-14-2020, 09:01 PM - 1 Like   #10
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There is a kernel of truth in most of the posts above, although no one has mentioned the effect of heat affecting the sensor (which becomes exponentially more problematic as the size of the sensor increases) and the electrical requirements to take high quality photographs with such a large sensor. But the real killer is diminishing returns in terms of perceptible improvements in the quality of images taken with such a camera, coupled with overwhelming impracticality. Just because it is feasible, doesn't mean it is a good idea.
09-14-2020, 11:33 PM   #11
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shallow

also, the razor thin depth of field from that size digital chip would be pretty restrictive creatively , much less depth than a similar sized piece of film. Would almost have to be a bellows camera.
09-15-2020, 05:13 AM   #12
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As mentioned, cost and the very niche market (therefore increasing unit cost) is the reason - similarly I doubt there will be an 'expensively affordable' FF 645. While the D is a fantastic camera and handles exceptionally well - I can't help thinking I'd prefer it in a 33x44 67ii type form factor with the 645 mount (similar to the Leica S).
09-15-2020, 05:55 AM - 1 Like   #13
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The sensors get incredibly expensive as the size goes up. A big part of that is driven by yield, that is, the % of sensors that have relatively few defects out of the batch. A 40mm x 40mm sensors is in the neighbourhood of US$5000 to 9000. It easily jumps up to $30,000 to 90,000 for something larger like 60x60 in a class 1 (low defect) level. It's exponential cost, not linear.
09-15-2020, 07:27 AM   #14
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Also the cost of the lenses/accessories for this new 6x7 camera.

Your unlikely to ever see a full set of lenses/accessories like you did with the Pentax 6x7 system, as well as interchangeable viewfinders/focusing screens.

Phil.
09-15-2020, 07:59 AM   #15
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QuoteOriginally posted by johnha Quote
As mentioned, cost and the very niche market (therefore increasing unit cost) is the reason - similarly I doubt there will be an 'expensively affordable' FF 645. While the D is a fantastic camera and handles exceptionally well - I can't help thinking I'd prefer it in a 33x44 67ii type form factor with the 645 mount (similar to the Leica S).
Recently saw an "ugly" leica S 006 body for $1699. I had to research it. A man in Hong Kong makes custom adapters for Pentax 645 lenses on Leica S. The Leica forum is full of people shooting Pentax lenses. They are very happy with Pentax and love the 75mm. So your dream combo is already "'available".

If something ever happened to Pentax MF, I could see myself with a used Leica body. I'd probably prefer it to Fuji. Amazing how short the registration distance is on the Leica.

Thanks,
barondla
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