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02-20-2015, 02:25 PM - 1 Like   #16
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A 50mp FF sensor and firmware could offer these shooting modes:
  1. 50mp FF.
  2. 22mp crop, almost identical to the K-3.
  3. 12.5mp FF 2x2 binned. Reduced noise in dim light, similar to downsampling in PhotoShop but you get it straight from the camera. This mode might also provide unlimited burst length with high-speed continuous shutter for action shooters.
That sensor arrangement would allow a single camera to fill the role of multiple specialized cameras, like having a Sony A7R and A7S selectable from a menu.


Last edited by DeadJohn; 02-20-2015 at 02:30 PM.
02-20-2015, 02:29 PM   #17
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I think that if Pentax plans to only launch a single FF for the time being, it should have a higher resolution than the K-3 as one of its selling points. At the same time, it should have lower noise. Thus, a 36 megapixel sensor would fit the bill perfectly.

I doubt that they will use a 50 Mp sensor since a) it was only just launched by Canon and b) it might undermine the 645Z's high-res appeal.

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02-20-2015, 02:47 PM   #18
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QuoteOriginally posted by biz-engineer Quote
The reasoning behind the 50Mpixel sensor is to equal the analog film in terms of resolution. How many Mpixel does analog film has? Infinite?
No and no. Film does not have Megapixels, though it does have resolution and that resolution can be measured. It is expressed as an MTF graph*. It is possible to provide a theoretical calculation, but probably the best way to compare is to consider maximum print size. An excellent 35mm negative produced using excellent technique and the best available lenses is capable of supporting a 24"x36" silver-based print with reasonable visible detail (or may even 32"x48"). The maximum print size for a 36Mpx camera at a nominal print resolution of 300 dpi is a little larger than 16"x24". Normhead will argue that 150-200 dpi would be acceptable resulting in a max of 32"x48". In the real world, I would suggest that the two are comparable.

If you wish to compare scanned film, the best drum scanners are capable of 11,000 dpi with a dynamic range in excess of 4 dMax. That is a lot of megapickles and dynamic range. However, I am not sure that the prints from those scans will provide higher quality than an optical print.


Steve

* The film makers publish their graphs. Kodak T-MAX 100 has f50 = 125 lp/mm according to the published datasheet. Other specialty emulsions have resolutions as high as 160-180 lp/mm IRRC.
02-20-2015, 02:59 PM   #19
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QuoteOriginally posted by biz-engineer Quote
The reasoning behind the 50Mpixel sensor is to equal the analog film in terms of resolution. How many Mpixel does analog film has? Infinite? Nobody complained about infinite resolution during the film era. If I understand correctly, with films the image is not sampled in the way digital sensors do, therefore, on film, the resolution is limited by the lens optical bandwidth and film grain (if I'm not wrong... actually I'm too young to remember how film works exactly). With 24Mpixels, a AA filter is needed (not needed for film) and therefore is an additional layer that reduce resolution and perhaps light transmission also for low frequency image components. With 50 Mpixel , no AA filter is needed, it's like if a 35mm film is directly replaced by a 35mm digital sensor.
If I remember well, the size of film grains was 12 micrometer for common, not industrial or military film. 12 micrometer is way bigger than today pixels, which are just under 5 microns for K-5 sensor, and 4 microns for K-3. And I'm not talking about the real size of active part of a pixel, but the size of the microlenses posted in front of it, or the distance between 2 pixels.

And also, if I remember well, Digital SLR became attractive for most photographers after they pass the 6Mp barrier, (at a right price), which correspond to a film grain of 12 microns on a film size of 36x24mm.

02-20-2015, 03:19 PM   #20
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QuoteOriginally posted by stevebrot Quote
In the real world, I would suggest that the two are comparable.
To expand a little more on the above and consider the case of a 50Mpx sensor, it is enough to say that a 50 Mpx sensor for the 35mm format would blow most films away. That is assuming, of course, that the sensor is able to provide a clean 50 Mpx with reasonable dynamic range. Noise is problematic in that each noise pixel translates to a loss of a data pixel. The damage does not end there, however since that region of the image is composed of the lost pixel in conjunction with the values of its near neighbors. Noise, even if well corrected, translates quickly into lost detail.

Probably one of the best examples of the above would be the noise comparison photos on this site's review of the Pentax 645Z. Images (both scaled and unscaled) were made using the 645Z (50Mpx), D810 (36Mpx), K-3 (24Mpx), and K-50 (16Mpx) at ISO 100, 1600, and 6400. The results were quite telling with the K-50 holding its own for retained detal over the K-3 at all but ISO 100. The 645Z was the clear winner overall, but the noise characteristics of the D810 sensor were impressive.

Pentax 645Z Review - Detail and Moire | PentaxForums.com Reviews


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02-20-2015, 03:30 PM - 2 Likes   #21
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QuoteOriginally posted by JimmyDranox Quote
If I remember well, the size of film grains was 12 micrometer for common, not industrial or military film.
Actual film grain (sort of a misnomer) size is much smaller than that. Fundamental particle size is about 0.2μm - 2.0μm with many of the actual silver crystals being much smaller. Any analogy between grain size and pixel size, however, would be false since pixels have a defined range of values based on the light intensity striking the lens of each of the three sites with the entire frame being filled with pixel sites. A fundamental particle, on the other hand, is not perceived as a single entity and its contribution depends on its size, shape and orientation and the characteristics and spacial orientation of its near neighbors. Both the particle characteristics and density contribute to the image characteristics. In other words, it is an apples vs. bubble gum comparison. Both have flavor, but that is where the comparison ends.

There is more to film resolution and acuity than grain size.

See: http://cool.conservation-us.org/coolaic/sg/emg/library/pdf/vitale/2007-04-vi...resolution.pdf

(from the Stanford University, Conservation Online project http://cool.conservation-us.org/)


Steve

Last edited by stevebrot; 02-20-2015 at 03:55 PM.
02-20-2015, 03:44 PM   #22
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If I want crop mode I will continue to use my K-3.

I would be happy with 24-36 Mp for the full frame. Equal or better resolution than the K-3, and better high ISO performance, without maxing out the camera's processing engine (and my computer), or eating into the 645Z's market.
02-20-2015, 03:48 PM   #23
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QuoteOriginally posted by biz-engineer Quote
Working in the semiconductor industry, there are some cost models that indicate that cost of silicon is not a function of image sensor resolution but it is proportional the silicon area and the number of steps needed in the manufacturing process. Therefore , FF cameras should have the higher pixel count , at the same price point as the lower pixel count , as long as the size of pixels does not impact the defect rate of the sensors. Practically, defect rate is a function of silicon area a defect density given a specific fab, rather than pixel density. Therefore, the new Pentax FF should be equipped with a 50Mpixels sensor, and not a 24Mpixels sensor.
Having the new Pentax FF with 51Mpixel has a lots of advantages:
- give a reason to k-3 owner to buy a FF cam
- sensor with 51Mpix gets rid of AA filter, same advantage as the K-3 but on larger sensor.
- sensor is almost the same cost with 51Mpix versus 24Mpix
- bring Pentax again very competitive in the full frame segment , able to compete with new Nikon FF and Canon FF (if Canon has done the 5DS, Nikon will follow).

What is your opinion?
My opinion is that I like the way you think.

You're basically saying what the IC/sensor engineers have been saying on dpreview for a while. However I doubt that or any 51MP sensor is going to be available to Pentax in 2015. My guess is we'll see the 36Mp Sony Exmor.

Also not to speak for anyone, but when folks say "XX MP is too much" I think they're really saying "I don't want to sacrifice SNR/DR for resolution."

That's a very valid position, but I think it's kind of a false choice - you don't have to sacrifice SNR/DR for resolution, you can have both (within reason.)

I say bring on the MP. It puts more cameras in your FF body, as dead john said, it gives you more ability to crop, print/display bigger, and gives you more data to work with in post. The images just hold up better.


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02-20-2015, 04:18 PM   #24
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QuoteOriginally posted by biz-engineer Quote
Working in the semiconductor industry, there are some cost models that indicate that cost of silicon is not a function of image sensor resolution but it is proportional the silicon area and the number of steps needed in the manufacturing process. Therefore , FF cameras should have the higher pixel count , at the same price point as the lower pixel count , as long as the size of pixels does not impact the defect rate of the sensors. Practically, defect rate is a function of silicon area a defect density given a specific fab, rather than pixel density. Therefore, the new Pentax FF should be equipped with a 50Mpixels sensor, and not a 24Mpixels sensor.
Having the new Pentax FF with 51Mpixel has a lots of advantages:
- give a reason to k-3 owner to buy a FF cam
- sensor with 51Mpix gets rid of AA filter, same advantage as the K-3 but on larger sensor.
- sensor is almost the same cost with 51Mpix versus 24Mpix
- bring Pentax again very competitive in the full frame segment , able to compete with new Nikon FF and Canon FF (if Canon has done the 5DS, Nikon will follow).

What is your opinion?
Perhaps a wafer with 50mp and one with 36mp costs the same to manufacture, but it will require faster processors and more advanced hardware to handle the extra data, so, overall, it will make the camera cost more.
02-20-2015, 04:32 PM   #25
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QuoteOriginally posted by stillshot2 Quote
Perhaps a wafer with 50mp and one with 36mp costs the same to manufacture, but it will require faster processors and more advanced hardware to handle the extra data, so, overall, it will make the camera cost more.
And I sure hope that is the way they go - I want to see dual processors in the FF if it's 36MP. And a buffer big enough that the camera *never* slows down when shooting. Ever ever ever. So what if the price is $10 higher?

I took two bodies to an airshow once; K10D and K20D. Both have unusual burst characteristics; the K10D won't ever slow down (at 3fps, no big surprise...), and the K20D has that not-quite-a-video-format in the 22fps still burst mode. Both were kinda neat to use until I could get the timing down. But the K10D was more reliable, since it never locked up while writing.
02-20-2015, 05:10 PM   #26
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I think Ricoh has to stick with the 36MP sensor unless they have some serious processing power and memory. How much memory and processing power will it take to use the SR to stack 8 exposures of 50MP 16-bit RAW and merge them into a single RAW file? Even 36MP is going to take huge amount of processing power. I like 36MP because it doesn't really need an AA filter and if you are using the SR for stacking images you eliminate practically all digital artifacts.

I'm using the A7m2 with its 24MP sensor and I'm not having any issues printing A3+ which is my target size. I'm not opposed to 36 or more mega-pickles, but resolution past 24MP is not a priority for me.

How many MBs would 8 50MP 16-bit image files require, and how much processing power would be needed to complete the action in a reasonably short period of time?
02-20-2015, 05:43 PM   #27
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QuoteOriginally posted by kiwi_jono Quote
I don't really care how many megapixels the FF has in crop as long as the high ISO performance is as least as good as my K-5 (which is good for a APS-C).

Personally for what I shoot I find 16 MP more than enough. Granted an advantage of higher MP is that it gives more opportunity to crop more.

I'm hoping the FF is not over 36MP but then as long as high ISO is good I'm not that fussed.
+1 on this. I would like to see it right at 36mp. Im hoping they don't go higher as it seems the Pickle war is heating back up for some strange reason ??? When are people gonna "Get It"....more just isn't needed !
02-20-2015, 06:06 PM   #28
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At the time when 6MP were becoming standard, the German c't magazine made a rough calculation how many MPs would be needed to equal the results of every days's use of film cameras, resolution-wise. They compared with a ISO 100 slides film and a good standard prime lens.
For the sensor and filters, they assumed a technology like that of the *istD sensor.

Their result was, that 12MPs could provide an equal resolution. To compare with lower resolution films (specially B&W) paired with top of the line lenses, some more would be needed.
So, from theory, resolutionwise the 24MPs of the K-3 should be more than any 24x36 film camera ever could achieve. Even 36MP should be a big step to analog MF, 50MP certainly overkill.
02-20-2015, 08:17 PM   #29
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I doubt Ricoh will do a 50 MP FF in 2015. Using my crystal ball, things will probably work like this:

mid 2015 - Sony releases a 50MP A9, shortly afterwards Nikon announces a 50MP D900, Pentax announces a 36MP FF.

If Pentax wants a 50MP FF, they'll probably have to take their place at the end of queue, so maybe by early 2017 at best they'll be able to do a 50MP.
02-21-2015, 03:03 AM   #30
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QuoteOriginally posted by Winder Quote
I think Ricoh has to stick with the 36MP sensor unless they have some serious processing power and memory. How much memory and processing power will it take to use the SR to stack 8 exposures of 50MP 16-bit RAW and merge them into a single RAW file? Even 36MP is going to take huge amount of processing power. I like 36MP because it doesn't really need an AA filter and if you are using the SR for stacking images you eliminate practically all digital artifacts.

I'm using the A7m2 with its 24MP sensor and I'm not having any issues printing A3+ which is my target size. I'm not opposed to 36 or more mega-pickles, but resolution past 24MP is not a priority for me.

How many MBs would 8 50MP 16-bit image files require, and how much processing power would be needed to complete the action in a reasonably short period of time?
I think this is a very good reason. . If the FF would Come soon it would run on PRIME II , but I guess that we will have the New milbeaut on board by the time the FF reaches the market. So that would be like 50 % faster processing then currently inside K-3. I think 8 50MP 16-bit RAW would take the time to drink Coffee.
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