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Author Topic: The future of medium format  (Read 17862 times)
Emilmedia
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« Reply #40 on: December 13, 2012, 01:57:34 PM »
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For my type of portrait/commercial type of shooting live view is a pain in the ass. I prefer the viewfinder any day. I just dont want too much information around me when I compose.

And the talk do CCDS not having good enough iso. Look at the noise of the new canons. They are terrific. imagine that technology on a 645 sized sensor. But then again, the same technology that's in the D800 sensor... Hard to believe how incredible that would be.

Dynamic range would be out of this world.
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BJL
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« Reply #41 on: December 13, 2012, 02:37:07 PM »
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Live view would be ... not so meaningful for the typical 645 DSLR use case when you hand-hold the camera and look through the viewfinder.
One part of live view is the option of an eye-level EVF (I can imagine MF cameras keeping the OVF and also offering an accessory eye-level EVF), which could be very useful also for accurate manual focusing while hand-holding the camera, due to the ability to magnify near the selected focus target. This would probably work best if the magnified image occupied only part of the VF image, with the overall framing still shown around it, but I get by without that when manually focusing my E-M5. Focus peaking in the eye-level EVF could also be useful, according to those who have experience with it.

Live view also opens up another old-school medium format style: cradling the camera at waist level, with forearms braced againsts hips and looking down on the up-tilted external monitor. This is actually a very stable way to hold a camera, as one can see by using a highly magnified live view image with IS off, to show how much the image shakes. By the way, unstabilized and highly magnified live view with a long focal length also teaches humility about one's hand-holding abilities! The ability to engage IS while focusing helps greatly, but that might be slow to come to MF, because (a) the existing lenses lack it, and (b) sensor based stabilization might be a big mechanical challenge with larger sensors and the relatively small R&D budgets of the MF makers.
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Vladimirovich
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« Reply #42 on: December 13, 2012, 03:04:25 PM »
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Dynamic range would be out of this world.

being that real mf sensors are way less than 4 times larger than ff sensors DR will be less than 2 stops more... that is hardly out of this world... specifically if the sensor will come not from Sony but from some lesser skillful manufacturer.
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FredBGG
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« Reply #43 on: December 13, 2012, 03:16:13 PM »
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Down sampling in post in theory produces one stop gain in per pixel noise.
Pixel binning produces two stops.

In practice I find pixel binning to be a bit better than one stop difference; why? I could only speculate (maybe related to the modest ineffeciencies of demosaicing?)

But what do I know? I'm not looking at dXo charts, I'm only looking at raw files from said cameras in their native processor.

Down sampling does reduce noise... it's not a theory. It is used in many fields including still and motion picture. Many features are shot at a higher res than distribution, but for
celluloid and digital distribution.

DXO graphs are a valid source. Even Phase One refers customers to DXO. I remember getting emails when the IQ180 report was published and Phase One refers to
DXO on it's website:

http://www.phaseone.com/en/Camera-Systems/Camera-Bodies/Reviews.aspx

Anyway here are some images of sensor plus from a P65+


ISO 800


ISO3200


800 ISO scaled over the 3200 ISO

While the noise appears similar at the same magnification it is far better when the ISO 800 is scaled and it looks better than
one stop to me.

We all know that noise increases quite dramatically with MF CCD sensors and not in a linear manor once you go over 400/800.
Most likely the noise increase would have been worse even with down sampling with an IQ180 80mp ISO 1600 capture.
So the choice of using binning is a good move or else they would not have done it. But it's worth keeping in mind that it
is to address the limitations of CCD sensors when it comes to high ISO.

The advantage though of having sensor plus is worth noting.
Slightly faster frame rate 0.7 fps (0.9 fps in Sensor+ ) for the IQ180. That may not seem like a big difference, but for such a slow camera it is
a 28% speed increase. There are also work flow advantages. If you are going to down sample it can be an advantage to have the camera do it at the get go.

However it's worth considering if it's worth the extra cost as sensor plus is far from free. The Leaf backs don't offer sensor plus,
but shoot at full MP count at ISO 800 and can be scaled down. The difference in price is quite significant especially if
you keep in mind that you can get the Leaf form B and H as well as Adorama.

I think this reinforces the argument for CMOS for MF.
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FredBGG
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« Reply #44 on: December 13, 2012, 03:24:14 PM »
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For my type of portrait/commercial type of shooting live view is a pain in the ass. I prefer the viewfinder any day. I just dont want too much information around me when I compose.

Live view can be with and without information being displayed.

Face recognition guided magnified live view is brilliant for live view portrait shooting especially for groups.
It is currently in the D800 and is something that could be implemented in in medium format cameras with CMOS live view.

That said I think it's important to keep OVF as part of the MF systems.
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Emilmedia
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« Reply #45 on: December 13, 2012, 03:29:17 PM »
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Hey Fred, I wasn't talking about the info on the screen. I ment I like how the viewfinder is like an off switch to everything around that happens in the room or environment. Makes me focus better.
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BJL
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« Reply #46 on: December 13, 2012, 03:36:43 PM »
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Hey Fred, I wasn't talking about the info on the screen. I ment I like how the viewfinder is like an off switch to everything around that happens in the room or environment. Makes me focus better.
Then you would prefer your live view through an eye-level EVF, not just a rear-screen monitor. You seem to be thinking only of the latter form ormlive view, perhaps becuase that is all that DSLRs currently offer. The mirrorless system cameras and Sony's "SLT" cameras have experimented more with different ways of using live view than DSLRs have, and so offer a richer preview of the directions that photographic technology might go.
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FredBGG
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« Reply #47 on: December 13, 2012, 07:01:27 PM »
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Hey Fred, I wasn't talking about the info on the screen. I ment I like how the viewfinder is like an off switch to everything around that happens in the room or environment. Makes me focus better.

You can use a loup with a nice large eye cup. This isolates you well, but you are right you are looking at a video screen. They are getting better and better, but it's different from
looking right at reality through a focusing screen However there are some big advantages to live view view finders.
One I particularly like is black and white preview while still shooting a color raw.

Best thing for the future of MF is to have both.
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theguywitha645d
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« Reply #48 on: December 14, 2012, 09:33:48 AM »
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We all know that noise increases quite dramatically with MF CCD sensors and not in a linear manor once you go over 400/800.

Well, the 645D is a couple of years older than the other cameras here, but there is no really difference between them at ISO 1600. Perhaps the CMOS sensors are really not that much better.
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ErikKaffehr
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« Reply #49 on: December 14, 2012, 10:46:02 AM »
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Hi,

We all know what we know, at least until we know better ;-)

Your observation is a "good catch" and also in agreement with DxO-mark, see below.

Best regards
Erik


Well, the 645D is a couple of years older than the other cameras here, but there is no really difference between them at ISO 1600. Perhaps the CMOS sensors are really not that much better.
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BJL
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« Reply #50 on: December 14, 2012, 01:13:06 PM »
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Hi,

We all know what we know, at least until we know better ;-)

Your observation is a "good catch" and also in agreement with DxO-mark, see below.
At the common exposure index values, at least up to 800, the signal at 18% is high enough that shot noise dominates over sensor dark noise, so differences will come only from differences in well capacity. So what you see is primarily the noise inherent in the incoming light, not from the sensor. The main difference is that beyond Exposure Index 800, the 655D starts to fall behind.

What this 18% "print normalized" noise graph shows is at Exposure Index up to about 800, the noise level differences due to sensor dark noise differences are only seen in shadows, not mid-tones, and that sensor noise only starts to significantly effect mid-tones from about EI 1600.

This offers a caution about wrongly extrapolating from DR measurements based on the noise floor in very dark parts of the image to conclusions about visible noise in images at low to moderate EI! The watch-face comparisons reinforce this, even with significant parts of the image a stop or so below 18% midtone level, but still not way down in the depths where sensor noise is the dominant noise source.

I wuld love to see something like 2% or 4% SNR measurements, as an indication of noise in shadow regions two or three stops below midtones: regions that are still relevant to straight, not-contrast compressed, prints.
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FredBGG
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« Reply #51 on: December 14, 2012, 01:27:37 PM »
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Actually it's the skin tones that are more of a problem with the 645D at high ISO.
While the Pentax does a very good job with high ISO as far as luminance noise goes
it's not good on skin tones at ISO 1600.

Being a portrait photographer it's the skin tones I look at and due to the type if lighting I use
I also look at the color in the areas of skin tone that fall into the shadows.

Having taken a look at the Pentax 645D I decided against mainly due to the 44x33 sized sensor,
but also for the high ISO skin tones.
They are more ashy and slight green patches appear in the gradations of the skin.

Anyway you can see what I am talking about from the same DPreview test comparison tool
that was shown above.



And here is the Pentax image laid over the Nikon image



The Nikon has more color in the skin tones and if you drop the saturation to that of the Pentax
you will also reduce chroma noise.


Pentax image laid over the Nikon image with saturation corrected to match.

On top of this in a low light situation but with more contrast which is often the case in
night scenes the dynamic range of the camera combined with ISO perfomace comes into play.
The D800 (CMOS) has a one and a half stop dynamic range advantage.



Now that said the Pentax 645D is a lovely camera with many features that distinguish it from the other MFDB cameras.
The ergonomics are really good and what is most important it comes from a company that has significant CMOS experience
and they are likely to be the ones to make the jump over to CMOS. They also already have a good relationship
with CMOS manufacturers and already use Sony sensors.

A full frame CMOS sensor in a Pentax 645D with Pentax pricing and image stabilization
in the right lenses and I think I might get one.

« Last Edit: December 14, 2012, 01:55:15 PM by FredBGG » Logged
theguywitha645d
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« Reply #52 on: December 14, 2012, 01:43:20 PM »
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The main difference is that beyond Exposure Index 800, the 655D starts to fall behind.

Two pieces of data posted here show that at 1600ISO, there is no falling behind with the 645D.
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theguywitha645d
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« Reply #53 on: December 14, 2012, 01:47:21 PM »
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They are more ashy and slight green patches appear in the gradations of the skin.

Fred, with controlled lighting, why would you even want to shoot at ISO 1600? Not your typical speed for portrait work. If you are simply working in bad light, then it is not even worth mentioning as the light is not going to be ideal to reproduce color accurately anyway. Pity the Nikon color is so yellow for skin. It looks like both cameras need some work.
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FredBGG
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« Reply #54 on: December 14, 2012, 02:11:42 PM »
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Well, the 645D is a couple of years older than the other cameras here (d800), but there is no really difference between them at ISO 1600. Perhaps the CMOS sensors are really not that much better.

Even if there were not difference it would still make a case for CMOS because with the Cmos camera achieves what it does at a 1/3rd of the price and a smaller sensor.

Fred, with controlled lighting, why would you even want to shoot at ISO 1600? Not your typical speed for portrait work. If you are simply working in bad light, then it is not even worth mentioning as the light is not going to be ideal to reproduce color accurately anyway. Pity the Nikon color is so yellow for skin. It looks like both cameras need some work.

Actually there is not too much yellow. In the overlay all I did was lift saturation.

Regarding why I would want to shoot ISO 1600...... Might not be typical, by often in natural light situations the light can be really beautiful, but not much of it.
Also another situation where it is relevant is when I shoot an actors portrait on a TV digital (as compared to film) set. Sometimes I have little time
and I have to use the available lighting. In these situations the light for the whole scene tends to be very flat as well as quite low. Often to find
more interesting light I either have to go to the edge of the lighted scene to find some interesting fall off or use flags to carve the light a bit.

I'm not trying to trash the Pentax. I think it is a lovely camera. I just find it is held back by the size of it's sensor (44x33 in a 645 body) and the limitations of CCD sensors.
Never hear of the camera crashing or freezing.  
« Last Edit: December 14, 2012, 10:04:20 PM by FredBGG » Logged
Vladimirovich
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« Reply #55 on: December 14, 2012, 02:43:30 PM »
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Anyway you can see what I am talking about from the same DPreview test comparison tool
that was shown above.


it is not a good idea to use DPReview comparisom - first of all they are not good w/ using the same illuminations between their tests, then they are using ACR which applies different hidden mandatory corrections for different camera, then DPReview does not compare at equal ISO measured by sensor saturation (DxOMark) but at nominal ISO (which is basically tells that you can use whatever gain you want for as long as your in camera JPGs a conforming to a certain criteria - which makes that nominal ISO not a good idea for a raw shooter, who wants to expose to saturate the sensor properly)...
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theguywitha645d
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« Reply #56 on: December 14, 2012, 02:59:27 PM »
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Actually there is not too much yellow. In the overlay all I did was lift saturation.

Regarding why I would want to shoot ISO 1600...... Might not be typical, by often in natural light situations the light can be really beautiful, but not much of it.
Also another situation where it is relevant is when I shoot an actors portrait on a TV digital (as compared to film) set. Sometimes I have little time
and I have to use the available lighting. In these situations the light for the whole scene tends to be very flat as well as quite low. Often to find
more interesting light I either have to go to the edge of the lighted scene to find some interesting fall off or use flags to carve the light a bit.

I'm not trying to trash the Pentax. I think it is a lovely camera. I just find it is held back by the size of it's sensor (44x33 in a 645 body) and the limitations of CCD sensors.
Never hear of the camera crashing or freezing. 

The point is Fred, there is no case that CMOS in inherently better than a CCD at high ISO, at least up to 1600. The differences are too small to be significant. The Pentax at ISO 1600 is as good as any 35mm DSLR. Except for Live View, there is no limitation to a CCD.
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yaya
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« Reply #57 on: December 14, 2012, 03:03:44 PM »
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Just for fun I took the two 100 iso RAW files, opened them in ACR 7.2, neutralised them on one of the X-Rite patches and lifted the shadows:

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Vladimirovich
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« Reply #58 on: December 14, 2012, 03:37:19 PM »
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Just for fun I took the two 100 iso RAW files, opened them in ACR 7.2, neutralised them on one of the X-Rite patches and lifted the shadows:

D800e was 2/3 of a stop underexposed... it is about quality of dpreview shots for raw files comparison
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Doug Peterson
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« Reply #59 on: December 14, 2012, 03:37:39 PM »
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it is not a good idea to use DPReview comparisom - first of all they are not good w/ using the same illuminations between their tests, then they are using ACR which applies different hidden mandatory corrections for different camera, then DPReview does not compare at equal ISO measured by sensor saturation (DxOMark) but at nominal ISO (which is basically tells that you can use whatever gain you want for as long as your in camera JPGs a conforming to a certain criteria - which makes that nominal ISO not a good idea for a raw shooter, who wants to expose to saturate the sensor properly)...

Making prognostications about a camera based on downloading DPReview comparisons is deeply flawed and a very shallow approach to analyzing the difference between two cameras. For several reasons, a few of which you mention.

Especially for higher ISO shots, or for analysis of color, both of which are EXTREMELY dependent on raw processor version, settings, and preferences.
« Last Edit: December 14, 2012, 03:40:04 PM by Doug Peterson » Logged

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