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Author Topic: rumor: Pentax 645D Price: $6500 USD  (Read 92924 times)
Doug Peterson
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« Reply #440 on: June 04, 2010, 01:14:40 PM »
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Quote from: bcooter
If I'm working in studio, with flash, I find the digital backs (at least the phase backs I own) to have a lot more detail and a much deeper file to work in post.

But for me it starts and stops with flash in studio, maybe location if there is no continuous ambient light.

Now if I work with any continuous light, especially mixed lighting, I find the exact opposite and having shot the 5d2, next to my phase backs, in these conditions the Canon has at least as much dr or whatever anyone wants to call it and overall is a much easier file to work.  The detail I find even between the Canon and the Phase with continuous light.

At 400 iso I find the shadow noise with my backs to be much more pronounced (and not near as pretty) as the Canon, but the biggest killer for me working with continuous and ambient light and the phase backs is the color proliferation.  They seem to be tuned to pick up every single color in the room and we are always painting out blotches in skin, or contamination from some ambient light, even backlight

Yep that's about right.

At base or low ISO the P30 has much more fidelity / file-flexibility. At higher ISOs the Canon has more fidelity / file flexibility.

That's one reason why Phase developed the Sensor+ system which allows you to gain two stops of ISO without any loss in quality (though at a lower pixel resolution) so that you can retain the enormous file-flexibility and fidelity of the image as you increase the ISO.

Color accuracy always comes at the price of color accuracy :-). Being able to distinguish very subtle variations in color and areas of low saturation is great when doing product photography / art reproduction / landscape but not so great for fashion in uncontrolled lighting environments. Personally I'd rather have the accuracy and retouch out any undesirable accuracy than to have a camera which cannot pick up on subtle colors. I've had more than a few calls from photographers who had dSLRs that could not pick up the difference between two thread colors in an outfit (usually red), two hair shades, two paint colors etc and the client was not happy.

The Skin Tone tab in the Color Editor can create a gorgeous skin-tone profile (either a generic one that works pretty well for most models, or a very specific one that works perfectly for a specific model)

Doug Peterson
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bcooter
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« Reply #441 on: June 04, 2010, 02:40:12 PM »
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Quote from: dougpetersonci
but not so great for fashion in uncontrolled lighting environments. Personally I'd rather have the accuracy and retouch out any undesirable accuracy than to have a camera which cannot pick up on subtle colors. I've had more than a few calls from photographers who had dSLRs that could not pick up the difference between two thread colors in an outfit (usually red), two hair shades, two paint colors etc and the client was not happy.

The Skin Tone tab in the Color Editor can create a gorgeous skin-tone profile (either a generic one that works pretty well for most models, or a very specific one that works perfectly for a specific model)


I'm not talking about uncontrolled lighting, I'm saying if you go out side on green grass with a 12x rag over the talent, expect yellow/green people and yes that's a big deal to fix.  

I've tried that skintone thing, it's ok, nothing that keeps you out of the paint brush and photoshop, but the medium format backs I own are just too damn color sensitive.  They see every blotch, every slight variation in skin tone and you can't globally correct for that.  I guess the skin tone editor thing would work better if you shot blue clothes, blue backgrounds and blue makeup, then it could single out the skintones, but it's not a fix and don't believe, then set it up next to the Canons and have a go at it with anything other than one softbox pointed at a face.

Try it and show it.

BC

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ErikKaffehr
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« Reply #442 on: June 04, 2010, 04:01:01 PM »
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Hi,

That's just 4 MP. If you downsample a 40 MP sensor to 4 MP you would get about the same DR. The Kodak sensor has a lot of read noise, BTW, around 20 electrons that would reduce DR to around 25000:1.

So, you would be better of with a smaller pitch sensor in almost all cases. If you need a 50mm x 50mm square sensor, it's a different case, but how much are you willing to pay for that?

Just to explain how it works:

The Kodak sensor has few but large pixels, so each pixel can hold about 500000 electrons. A 40 MP digital back may hold about 60000 electrons in each pixel. If we downsample the 40 MP sensor to 4 MP we get about 600000 electrons per (downsampled) pixel. In practice DR is limited by shot noise (random variation of photons falling on sensor pixels) and that variation would be the same weather 4 MP (downsampled) or 4 MP (real).

Best regards
Erik


Quote from: EricWHiss
Wow!  A 50mm x 50mm square sensor with 15 stops DR - sounds perfect!   I'll take one of these for my Rollei 6008  please!
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pschefz
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« Reply #443 on: June 04, 2010, 04:15:59 PM »
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Quote from: bcooter
I'm not talking about uncontrolled lighting, I'm saying if you go out side on green grass with a 12x rag over the talent, expect yellow/green people and yes that's a big deal to fix.  

I've tried that skintone thing, it's ok, nothing that keeps you out of the paint brush and photoshop, but the medium format backs I own are just too damn color sensitive.  They see every blotch, every slight variation in skin tone and you can't globally correct for that.  I guess the skin tone editor thing would work better if you shot blue clothes, blue backgrounds and blue makeup, then it could single out the skintones, but it's not a fix and don't believe, then set it up next to the Canons and have a go at it with anything other than one softbox pointed at a face.

Try it and show it.

BC

I totally agree.....some by the name of James wrote here a little while ago that the dmf backs show it in your models face if a red car drives by outside the studio.....and I completely agree.....

i always laugh when people talk about correct color.....most skin tones I see in print don't actually exist....but they look pleasant....
yes, there are situations where color is very important (fabrics, product,....) but in my experience the dmf backs don't really  have a much better track record then the dslrs.....and when you take moire into consideration the choice is clear again...

I am surprised to read about someone like rainer using dslr now.....but then again the 2 architectural photographers I know switched to dslr exclusively in the last year.....but I am with him all the way....I will get whatever canon comes out with next....

I have never liked shooting slrs.....I prefer mf and even rf.....but I really have no choice anymore....



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« Reply #444 on: June 04, 2010, 05:07:05 PM »
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Quote from: pschefz
I totally agree.....some by the name of James wrote here a little while ago that the dmf backs show it in your models face if a red car drives by outside the studio.....and I completely agree.....

i always laugh when people talk about correct color.....most skin tones I see in print don't actually exist....but they look pleasant....
yes, there are situations where color is very important (fabrics, product,....) but in my experience the dmf backs don't really  have a much better track record then the dslrs.....and when you take moire into consideration the choice is clear again...

I am surprised to read about someone like rainer using dslr now.....but then again the 2 architectural photographers I know switched to dslr exclusively in the last year.....but I am with him all the way....I will get whatever canon comes out with next....

I have never liked shooting slrs.....I prefer mf and even rf.....but I really have no choice anymore....

well i havent switched yet. i use both at the moment.
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rainer viertlböck
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pschefz
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« Reply #445 on: June 04, 2010, 05:43:44 PM »
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Quote from: rainer_v
well i havent switched yet. i use both at the moment.

i did not want to make it sound like you switched exclusively....2 people i know have....

architectural should really be a stronghold for dmf....and even in that field things are changing.....

on a side note....never got to see that rz33 but afaik it is just a rz with the aptus....which is a great back.....but why can't they make a wlf that makes the finder image look like 6x7? is it THAT hard?
once I hold a H or mamiya (or pentax) up to my eye, it turns into a dslr....only bigger, slower, with a laughable af....
am I the only one who wants what mf used to be?
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« Reply #446 on: June 04, 2010, 10:41:43 PM »
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Quote from: pschefz
once I hold a H or mamiya (or pentax) up to my eye, it turns into a dslr....only bigger, slower, with a laughable af....
am I the only one who wants what mf used to be?

I tested the P65+ on an H2 in Atlanta last week. Now THAT is an awesome viewfinder -- the large H image, coupled with no cropping. And the H2 shoots the P65+ very very fast, in full rez mode.
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EricWHiss
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« Reply #447 on: June 05, 2010, 12:53:39 AM »
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Quote from: ErikKaffehr
Hi,

That's just 4 MP. If you downsample a 40 MP sensor to 4 MP you would get about the same DR. The Kodak sensor has a lot of read noise, BTW, around 20 electrons that would reduce DR to around 25000:1.

So, you would be better of with a smaller pitch sensor in almost all cases. If you need a 50mm x 50mm square sensor, it's a different case, but how much are you willing to pay for that?

Just to explain how it works:

The Kodak sensor has few but large pixels, so each pixel can hold about 500000 electrons. A 40 MP digital back may hold about 60000 electrons in each pixel. If we downsample the 40 MP sensor to 4 MP we get about 600000 electrons per (downsampled) pixel. In practice DR is limited by shot noise (random variation of photons falling on sensor pixels) and that variation would be the same weather 4 MP (downsampled) or 4 MP (real).

Best regards
Erik

Yeah but don't get hung up on the theoretical DR from specs. The DR that matters to working photographers is measured differently.  It always comes up with the armchair arguments for MFDB vs DSLR and its just pointless to go down that path.   The biggest problem with that kodak sensor is not that its 4mp, but rather that its just a sensor.  We'd need some of that phase or imacon voodoo and downstream electronics to make it useful - well that and its only monochrome.  
« Last Edit: June 05, 2010, 12:58:16 AM by EricWHiss » Logged

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« Reply #448 on: June 05, 2010, 04:56:00 AM »
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Quote from: EricWHiss
Yeah but don't get hung up on the theoretical DR from specs. The DR that matters to working photographers is measured differently.  It always comes up with the armchair arguments for MFDB vs DSLR and its just pointless to go down that path.   The biggest problem with that kodak sensor is not that its 4mp, but rather that its just a sensor.  We'd need some of that phase or imacon voodoo and downstream electronics to make it useful - well that and its only monochrome.

If you want to see the *practical* DR difference, just pick up a Canon and a Leica M8 or M9, shoot at low ISO and look at the way the Leica marks the textures. Although I must say that one cannot complain about the 5D2.

With a Phase back, you can shoot a model in direct sun, and bring back the shadows in post. If the Raw software you are using is decent there will be no hue shifts while opening the shadows. Hint: the most popular prosumer Raw converter is not necessarily the one you really really want to use after spending all that money, the guys who made the back may be making decent software for it too.

Edmund
« Last Edit: June 05, 2010, 04:58:43 AM by eronald » Logged

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fredjeang
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« Reply #449 on: June 05, 2010, 05:05:09 AM »
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Quote from: eronald
If you want to see the DR difference, just pick up a Canon and a Leica M8 or M9 and look at the way the Leica sees into the shadows and marks the textures.

With a Phase back, you can shoot a model in direct sun, and bring back the shadows in post. If the Raw software you are using is decent there will be no hue shifts while opening the shadows. Hint: the most popular prosumer Raw converter is not necessarily the one you really really want to use after spending all that money, the guys who made the back may be making decent software for it too.

Edmund
Agree 100% Edmund

Cheers.
« Last Edit: June 05, 2010, 07:10:34 AM by fredjeang » Logged
ErikKaffehr
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« Reply #450 on: June 05, 2010, 09:45:56 AM »
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Eric,

The point I want to make is that there is no real advantage to a large pitch sensor over a small pitch sensor. Would that be the case the, Phase One couldn't charge 30 kUSD (or so) for the P65+. Actually, if you use the technical definition of DR (at SNR equal 1) there may be an advantage with large pixels, but normally it's more "shot noise" which limits the acceptable noise levels in the darks. So in theory it's sensor size that matters and not pixel size.

A disturbing fact is that it is very hard to find a single comparison of MFDBs and DSLRs using adequate methods. With adequate methods I mean:

1) Reproducible setup
2) Correct exposure to the right (so full well capacity is actually utilized)
3) RAW ord DNG images (so they could be analyzed by RawAnalyzer or other tools)

Such an experiment would be very easy to conclude for anyone having both kinds of equipment, but I have actually not seen any.

Also, it seems that there is an obsession with DR in these discussion. DR is not particularly easy to measure. There are other parameters that may be much more important.

1) Sharpness obviously, no one really doubts that there is a sharpness advantage of larger sensors
2) Color handling, this is much dependent on the Color Grid Array in front of the sensor but also on algorithms
3) Internal reflections, number of air/glass surfaces, baffling

The point I really wanted to make that making a 2500 squre mm sensor with four gargantuan size megapixels would not produce better DR (in print) than a similar sized sensor with ten times as many smaller pixels as photon counts would be the same.

Finally, even a "cheap" MF equipment is a major investment. So I'd imagine that it is important that potential buyers are well informed, armchair arguments or not. I'd also suggest that anyone considering an investment in an MF system should consider arranging an equipment for test/loan/rental before shelling out their money.

Best regards
Erik


Quote from: EricWHiss
Yeah but don't get hung up on the theoretical DR from specs. The DR that matters to working photographers is measured differently.  It always comes up with the armchair arguments for MFDB vs DSLR and its just pointless to go down that path.   The biggest problem with that kodak sensor is not that its 4mp, but rather that its just a sensor.  We'd need some of that phase or imacon voodoo and downstream electronics to make it useful - well that and its only monochrome.
« Last Edit: June 05, 2010, 09:58:38 AM by ErikKaffehr » Logged

fredjeang
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« Reply #451 on: June 05, 2010, 10:30:24 AM »
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Quote from: ErikKaffehr
Also, it seems that there is an obsession with DR in these discussion. DR is not particularly easy to measure. There are other parameters that may be much more important.
As always Erik, as always...

Still remember the famous thread about the DR Heresy...

Are you preocupated by DR ? Fine.

I'm preocupated by the viewfinder and if the controls are well implemented.

The only guests that are missing so far to complete this thread fest are the DxO plague and the PHD astro physics and quantic mechanics apply to photography.

IMHO.
« Last Edit: June 05, 2010, 11:42:51 AM by fredjeang » Logged
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« Reply #452 on: June 05, 2010, 10:53:57 AM »
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Quote from: eronald
If you want to see the *practical* DR difference, just pick up a Canon and a Leica M8 or M9, shoot at low ISO and look at the way the Leica marks the textures. Although I must say that one cannot complain about the 5D2.

With a Phase back, you can shoot a model in direct sun, and bring back the shadows in post. If the Raw software you are using is decent there will be no hue shifts while opening the shadows. Hint: the most popular prosumer Raw converter is not necessarily the one you really really want to use after spending all that money, the guys who made the back may be making decent software for it too.

Edmund

  The 5Dii has the least usable DR at low ISO of any fullframe out there right now.  Try bringing the shadows up a few stops, and it can be a banding mess in there.  The A900 also has issues (although not nearly as bad as the 5Dii) with color shift in shadows below ISO 320 when trying to raise shadows a few stops.  The D3x is certainly the current 35mm champ for extracting shadow details.

  Using uniWB and a magenta filter also goes a long way in improving your camera's DR.
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ErikKaffehr
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« Reply #453 on: June 05, 2010, 12:39:11 PM »
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Sorry,

I'm more preoccupied finding out what is feasible and what is not.

It's a bid odd. DxO makes some real research and it's called DxO plague. Regarding the issue on PhDs I would just say that without the engineering stuff we would have a nice cosy echo-logical world with horses and no cars, electric light, cameras, TV and so on. Living without DxO plague, but having the real plague, wouldn't that be nice?!

It is certainly true, world can be without science, understanding, physics and math. But, science, understanding, physics and math are the factors that makes six or seven billion people survive on this planet.

Now, science is not absolute truth, we all now that. Once we thought that earth was flat, that was good science in that time. When we got telescopes we could see that the flat earth model couldn't explain some issues and started to realize that earth was round. Our understanding of the world around us changes, tomorrow's theories will expand those theories we have today. But, without theories and understanding we would be like blind men in a dark cave!

My view is that we need to understand how our tools work. That understanding can help us to make the best investment in technology. Let's take one of those car analogies: we all know that Ferrari (or was it Roll's Roice?) that makes the best cars. But if you are in real hurry it's hard to beat a Learjet. A Bugatti Veiron may be even faster. On the other hand, if you travel with cameras, tripods, flashes and a couple models a Toyota may get you from point A to point B in the most efficient way.

In my view everyone is entitled to having his or her idea, but that's absolutely no good reason to show disrespect to work that others do. DxO presents their measurements to the community, no one else does that! Im my view DxO does deserve some credit for doing that. DxO also makes a raw converter, possibly not the greatest one, I don't know, but they certainly do know about raw conversion.

Michael Reichmann says that it is his finding that his experience is not conformant with DxO test. That's fine, I have acceptance for that. But calling serious work "plague" just because you don't agree, isn't that going a bit far?!

I really have an issue with this, some folks do some serious testing. Their results are not what readers expect, so they get all the blame. DxO came up with a figure of merit called the DxO-mark. I find it a bit stupid, because tools are used different ways. Talking for myself, I'm seldom using high ISO. High ISO is certainly a merit but not a very important one for me. But, if you study the DxO results with some care you are going to see they are relevant. Unfortunately it is very hard to correlate the DxO measurements to other data, simply because there are no other data available, but that is hardly DxO-s fault, is it.

Our friend "bcooter" on this forums explains this very well. Customers doesn't care about equipment, the results count and the Canon DSLRs he uses fill the bill, most of the time. He shoots Leica M9 for leisure and loves his Contax with MFDB. I also got the impression that he would not invest in a P65 until he is able to calculate a reasonable return on investment. Mr Reichmann is in a different seat, he wants optimum quality and went from P45 to P65.

An observation. According to DxO-mark the P65+ is considerably better than the Nikon D3X, even ignoring the resolution advantage. Also the Nikon D3x is significantly better than the Sony Alpha 900 and the Canon 5DII. At least in these cases the DxO figures seem to make sense.


An interesting observation that Erwin Puts seems to make is that the Leica S2 has a better image quality than the Nikon D3X which in turn is better than the Hasselblad H39. I guess that the interpretation of image quality is always a bit a question of viewing point and I don't always really understand how to interpret Mr. Puts's tests, but I still find his conclusion interesting.

Best regards
Erik

Quote from: fredjeang
As always Erik, as always...

Still remember the famous thread about the DR Heresy...

Are you preocupated by DR ? Fine.

I'm preocupated by the viewfinder and if the controls are well implemented.

The only think that are missing so far to complete this thread "as it should be" are the DxO plague and the PHD astro physics and quantic mechanics apply to photography.

IMHO.
« Last Edit: June 05, 2010, 12:55:12 PM by ErikKaffehr » Logged

fredjeang
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« Reply #454 on: June 05, 2010, 12:55:31 PM »
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Quote from: ErikKaffehr
It's a bid odd. DxO makes some real research and it's called DxO plague. Regarding the issue on PhDs I would just say that without the engineering stuff we would have a nice cosy echo-logical world with horses and no cars, electric light, cameras, TV and so on. Living without DxO plague, but having the real plague, wouldn't that be nice?!

Michael Reichmann says that it is his finding that his experience is not conformant with DxO test. That's fine, I have acceptance for that. But calling serious work "plague" just because you don't agree, isn't that going a bit far?!

I really have an issue with this, some folks do some serious testing. Their results are not what readers expect, so they get all the blame. DxO came up with a figure of merit called the DxO-mark. I find it a bit stupid, because tools are used different ways. Talking for myself, I'm seldom using high ISO. High ISO is certainly a merit but not a very important one for me. But, if you study the DxO results with some care you are going to see they are relevant. Unfortunately it is very hard to correlate the DxO measurements to other data, simply because there are no other data available, but that is hardly DxO-s fault, is it.

Our friend "bcooter" on this forums explains this very well. Customers doesn't care about equipment, the results count and the Canon DSLRs he uses fill the bill, most of the time. He shoots Leica M9 for leisure and loves his Contax with MFDB. I also got the impression that he would not invest in a P65 until he is able to calculate a reasonable return on investment. Mr Reichmann is in a different seat, he wants optimum quality and went from P45 to P65.

An observation. According to DxO-mark the P65+ is considerably better than the Nikon D3X, even ignoring the resolution advantage. Also the Nikon D3x is significantly better than the Sony Alpha 900 and the Canon 5DII. At least in these cases the DxO figures seem to make sense.


An interesting observation that Erwin Puts seems to make is that the Leica S2 has a better image quality than the Nikon D3X which in turn is better than the Hasselblad H39. I guess that the interpretation of image quality is always a bit a question of viewing point and I don't always really understand how to interpret Mr. Puts's tests, but I still find his conclusion interesting.

Best regards
Erik
Erik,

I have great respect for science. I love tech even if I do not understand maths equations.

In a F1 team, there is a lot of technology involved. But the mechanic is not the pilot neither the engineer. They are too busy with mastering their task.

DoX do some testings because that is what they are good at, but I do not call that photography, I call that datas compilation.
If you think that these numbers may help you, I'm fine with that and I respect each one's choice. But I'm also staying away from that.

I used the world plague not for DxO in itself, they want to do some mesurements? Great, fine, perfect. The plague is the abuse that is made from these mesurements, as arguments. Do I show disrespect for them? total lack of interest and confidence with these proceedings. But one thing is the number, other thing is the reality. This is not exact science or maths. This is an experiment, even serious, on mesurements. That point seems to not be understood so far despite the hundreds of postings about that fact from precisely the people you mentionned.

Trust your eyes. That is all I have to say. Trust what you see, and what the field experience tells you, regardless of the DRs and Co.
In ultimate instance, the DxO have zero interest if not to give us an aproximative idea of some tech parameters.

Trust the human brain and sensitivity. That is why photography is art and not just tech. It is above all that numbers.
It is vision and experience.

I agree 500% of what Michael, Guy Mancuso, Jack Flesher and others have been saying over and over again. So I agree with BC (1).

DR is nothing. Numbers are nothing (except the one when you write the checks).  Your vision is all. IMHO.

(1) You pointed BC, but it is strange because B.Cooter is precisely very pragmatic in all his posts. He is talking about skin tones and rendering in fashion=what he sees. Or he points technical issues that are always from the field. I think I never read a BC post about numbers, DxO, or even DR if not from field experience, and that is exactly for all these reasons that I trust him, or that I think his voice is a source of real knowledge. I don't see a tech, although I am aware he knows pretty well all the technical aspects, but I do see an artist. But has he said: "keep in mind that in a forum all the voices have the same weight...
« Last Edit: June 05, 2010, 03:06:12 PM by fredjeang » Logged
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« Reply #455 on: June 05, 2010, 01:32:42 PM »
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Hi Eric,

Thanks for your fast response. To clarify the issue I would like to believe my eyes but I don't have the means of testing a lot of different equipment. I guess that I also would need to print larger than I normally do to see meaningful differences. To me it seems that the "scientists"on this forum, like ejmartin, naetress, panopeeper and gluik and others actually find the DxO data informative. the other issue I really have is that there is a lot of talk but actually very little proof. It seems that people with humble equipment publish quite a lot of measurement data (I have myself supplied about 100 exposures to "panopeeper" so he could evaluate the sensor of the A900.)

On the other hand it seem tom me that folks having more exclusive equipment don't seem to make the effort to share some data. Any MFDB represents a significant investment, especially if you take all you need into consideration. I'd suggest that it would be nice if we could download a few representative images from different cameras and print using our own workflow to make an opinion, but there is actually very little to compare.

An exception was really the great 2006 MFDB shoot out here at LuLa. They even had the brilliant idea to use a 1 dollar bill as resolution test sample and had different MFDBs and using different apertures. I loved it!

The one dollar bill essentially mean that you can reproduce the test yourself, I have done that and found the advantage regarding resolution on the P45 very significant over my Alpha 900. I also found that stopping down the P45 equipment to f/22 (from f/8) essentially eliminated the advantage. Unfortunately, photographing a dollar bill tells a lot about sharpness but little about anything else. (These findings were based on interpretation of prints, so they were only presented verbally, as prints are hard to publish in electronic form.)

Here is my image of the dollar bill: http://echophoto.dnsalias.net/ekr/images/S...00_LLMFDBSO.dng

And here is a comparison of Velvia on Pentax 67 with Sony Alpha 900: http://echophoto.dnsalias.net/ekr/index.ph...date_2009_11_08


Regarding "bcooter", who I actually presume to be James Russel, I'd suggest that he is very pragmatic, and this is actually what I say.

The starting point for this discussion was a post of admiration for a 4 MP sensor with a theoretical DR of 15 stops, and I pointed out that any sensor of similar size would have a similar DR when the image was reduced to the same number of pixels. That has to do with photon statistics. DxO happens to have a very good article on the issue. Now, there is an opinion on these forums that large pixels are to prefer compared to small pixels, but this is not really true. Small pixels would yield the same image quality in most cases as large pixels with a benefit in resolution, less issues with moiré and aliasing artifacts and so on. The only disadvantage with smaller pixels is that files are growing larger if sensor surface is the same.

The reason that James Russel did not jump on the "P65+" is that he doesn't feel that he get gets the return on investment that would be needed. Customers don't pay for unneeded megapixels. He also says that his Canons do 90% of the work and he shoots Leica for private leisure. That's a pragmatic approach. Michael Reichmann feels that there is a significant advantage to his P65+ images compared to his 24.6 MP DSLR images, so he does much of his work with the P65+. In my view that is also a pragmatic approach.

Still I ask my self. Let's assume that a guy wants the ultimate equipment and shells out like 40 kUSD. What benefit will he get? Will he get magic benefits like 5-6 stops advantage in DR? Physically that would be hard to explain. Obviously he can get resolution advantages, but it may take some hard work to achieve it. Now, what benefits will he gain if he invests 10 kUSD in some used stuff. If he or she doesn't get the ROI expected he/she is standing with the expense. Talking is cheap, listening can be expensive. Good samples are gold but seldom found.

Best regards
Erik



Best regards
Erik Kaffehr
Quote from: fredjeang
Erik,

I have great respect for science. I love tech even if I do not understand maths equations.

In a F1 team, there is a lot of technology involved. But the mechanic is not the pilot neither the engineer. They are too busy with mastering their task.

DoX do some testings because that is what they are good at, but I do not call that photography, I call that datas compilation.
If you think that these numbers may help you, I'm fine with that and I respect each one's choice.

But, trust your eyes. That is all I have to say. Trust what you see, and what the field experience tells you, regardless of the DRs and Co.
In ultimate instance, the DxO have zero interest if not to give us an aproximative idea of some tech parameters.

Trust the human brain and sensitivity. That is why photography is art and not just tech. It is above all that numbers.
It is vision and experience.

I agree 500% of what Michael, Guy Mancuso, Jack Flesher and others have been saying over and over again. So I agree with BC.

DR is nothing. Numbers are nothing (except the one when you write the checks).  Your vision is all. IMHO.
« Last Edit: June 05, 2010, 01:59:52 PM by ErikKaffehr » Logged

fredjeang
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« Reply #456 on: June 05, 2010, 01:47:46 PM »
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Quote from: ErikKaffehr
Hi Eric,

Thanks for your fast response. To clarify the issue I would like to believe my eyes but I don't have the means of testing a lot of different equipment. I guess that I also would need to print larger than I normally do to see meaningful differences. To me it seems that the "scientists"on this forum, like ejmartin, naetress, panopeeper and gluik and others actually find the DxO data informative. the other issue I really have is that there is a lot of talk but actually very little proof. It seems that people with humble equipment publish quite a lot of measurement data (I have myself supplied about 100 exposures to "panopeeper" so he could evaluate the sensor of the A900.)

On the other hand it seem tom me that folks having more exclusive equipment don't seem to make the effort to share some data. Any MFDB represents a significant investment, especially if you take all you need into consideration. I'd suggest that it would be nice if we could download a few representative images from different cameras and print using our own workflow to make an opinion, but there is actually very little to compare.

An exception was really the great 2006 MFDB shoot out here at LuLa. They even had the brilliant idea to use a 1 dollar bill as resolution test sample and had different MFDBs and using different apertures. I loved it!

The one dollar bill essentially mean that you can reproduce the test yourself, I have done that and found the advantage regarding resolution on the P45 very significant over my Alpha 900. I also found that stopping down the P45 equipment to f/22 (from f/8) essentially eliminated the advantage. Unfortunately, photographing a dollar bill tells a lot about sharpness but little about anything else. (These findings were based on interpretation of prints, so they were only presented verbally, as prints are hard to publish in electronic form.)

Here is my image of the dollar bill: http://echophoto.dnsalias.net/ekr/images/S...00_LLMFDBSO.dng

And here is a comparison of Velvia on Pentax 67 with Sony Alpha 900: http://echophoto.dnsalias.net/ekr/index.ph...date_2009_11_08

Best regards
Erik Kaffehr
I remember that article. That was a great contribution.
It helped to have a pretty good idea.

But then, the results can be completly different according to the subject, type of printings etc...and what can work for you in a special configuration, would not work as well in another one, and this, independently of what the strict testings are showing.

In fact, if you are a fashion photographer, you have to do the testings in your area in real configuration. Because if not you can find big surprises.

I think Gwift (if I remember well) pointed before in this thread about that Pentax that he liked the 800 iso files, so did I, more than the lower isos in this case. A landscaper would probaly hate these 800 isos. It just depends on so many factors.

Cheers.

 


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fredjeang
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« Reply #457 on: June 05, 2010, 02:19:24 PM »
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Quote from: ErikKaffehr
Regarding "bcooter", who I actually presume to be James Russel, I'd suggest that he is very pragmatic, and this is actually what I say.
My impression, just reading the posts style, they are different.

Is that B.Cooter is the Dr Jekyll, and James Russel is the Mister Hide... of the same person so it is logical that he has doubled his membership.

But it is my strictly personal speculation.
« Last Edit: June 05, 2010, 02:22:32 PM by fredjeang » Logged
eronald
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« Reply #458 on: June 05, 2010, 04:46:08 PM »
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Quote from: fredjeang
My impression, just reading the posts style, they are different.

Is that B.Cooter is the Dr Jekyll, and James Russel is the Mister Hide... of the same person so it is logical that he has doubled his membership.

But it is my strictly personal speculation.

There used to be a very clever character called James,
who could masterfully grasp both sides of every question.
James was stressed and a bit contentious.

One day James flew apart,
And his fragments
Now represent each its side,
Courteously.

And all the king's horses,
And all the king's men,
cannot put the RG forum together again


Edmund
« Last Edit: June 05, 2010, 04:48:10 PM by eronald » Logged

Edmund Ronald, Ph.D. 
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« Reply #459 on: June 05, 2010, 07:21:36 PM »
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Quote from: ErikKaffehr
A disturbing fact is that it is very hard to find a single comparison of MFDBs and DSLRs using adequate methods. With adequate methods I mean:

I'll bet you that almost every working pro has and/or uses both MFDB and a DSLR and can tell you in which shooting/lighting conditions that they'd prefer to use one or the other.   A lot of serious amateurs have both cameras too.  If its such a big deal for you to find out then you should bring a couple memory cards and test charts down to your local store and shoot some images.  I don't think it would cost you anything except your time.
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