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PhaseOne introduces their IQ250 Digital Back

Jerome Marot

Well-known member
No, the above is not correct. What you are calling a "printer driver" and I am calling a "raster image processor" is a little more complex than that in its internal working. The internal working is not documented, since it is very much a trade secret of the respective companies involved.
 
No, the above is not correct. What you are calling a "printer driver" and I am calling a "raster image processor" is a little more complex than that in its internal working. The internal working is not documented, since it is very much a trade secret of the respective companies involved.
What you are saying is irrelevant Jerome, the printer does print anything at 600dpi but (obviously form its specs) misses one dpi as it advances the paper in y-direction. …does this looks sensible to you? …can you think on an alternative happening?
I don't refer on how it does it (that is a secret), I refer to what it does.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Jerome is one of the most knowledgeable people here and Theodoros, you know how to make smashing prints. But, guys, it's not in the spirit of OPF to be so confrontational.

Asher
 
Jerome is one of the most knowledgeable people here and Theodoros, you know how to make smashing prints. But, guys, it's not in the spirit of OPF to be so confrontational.

Asher
I'm sorry if you (or Jerome) thought that my intention was to offend Jerome Asher, I really never had such an intention, after all you must have guessed where I was getting too (which Jerome didn't let me suggest to him), which was nothing more than to show him on how to linearise his "pip"s with respect to his "dpi"s… (but first I had to find out the level that his printer resamples the signal). Of course you are right that sensor/lens combination is the most important factor for a good print much more so than sensor resolution or the number of "ppi"s that it appears to be for the selected size, but still, one has to avoid printing artefacts that the printer induces when sampling the input in order to maximise the outcome…
 

Doug Kerr

Well-known member
Indeed, the matter of mediating between the pixel dimensions of an image and the pixel dimensions of the print engine space in which it will be printed can be complicated (one of the many duties of the printer RIP).

And we must be careful not to confuse the pixel space of the printer with its dot space (although the terminology used often drives us to make that error).

Indeed, even in cases where the work should be trivial (an apparently integer relationship between the two dimensions), the intervention of that old gremlin, the "fencepost problem", can leave us trying to map 231 columns of image pixels onto 460 pixel columns of print engine space. And the result may not be "pretty".

That having been said, I have paid absolutely no attention to the arguments in this thread, since my allergist has forbidden me to attend catfights (and I am able to recognize an impending one by about D-2).

Best regards,

Doug
 

Andrew Molitor

New member
What I find odd about the MF gear is that all too often people will then go out and shoot landscapes and so on with it. You can use an entry level DSLR with a decent longish lens and stitch up the very same picture, with whatever medium-format-like rendering characteristics you like.

Actual usages where an MF back is necessary to get certain image characteristics seem to be very very very narrow indeed. A situation in which stitching is not feasible, extraordinarily high pixel counts are required, but great flexibility of motion is not.

The first suggests motion, the last suggests "but not too much", and the one in the middle suggests fine art.

I think this might boil down to fine art using impatient studio models? William Wegman, perhaps?
 

Doug Kerr

Well-known member
For those not familiar with the metaphor ""fence post problem", it is used by programmers to refer to a certain class of error that can frequently visit us. The metaphor comes from this parable:

A farmer needs to build a fence 100 feet long, with the posts at 5 foot intervals. He shows up at the job site with 20 posts in his wagon. Of course he is one short.​
If we have an image that is 500 pixels wide, and the first pixel is at column 0, the last pixel will be at column 499. So x2 - x1 is 499. But the width is 500 pixels.

And so forth.

The conventions used in Windows graphic interface calls avert this problem, replacing it with another.

Suppose we want Windows to draw a rectangle 100 pixels wide whose leftmost pixels are at pixel column 26. In the call to windows, we include the parameters left = 26, right = 126.

In fact the width of the rectangle is rightleft. Or the value of right is left+width. Very tidy.

So we need to know where the rightmost pixel of this rectangle is. Is it at column 126 (the value of right)? No, it is at column 125.

Best regards,

Doug
 
What I find odd about the MF gear is that all too often people will then go out and shoot landscapes and so on with it. You can use an entry level DSLR with a decent longish lens and stitch up the very same picture, with whatever medium-format-like rendering characteristics you like.

Actual usages where an MF back is necessary to get certain image characteristics seem to be very very very narrow indeed. A situation in which stitching is not feasible, extraordinarily high pixel counts are required, but great flexibility of motion is not.

The first suggests motion, the last suggests "but not too much", and the one in the middle suggests fine art.

I think this might boil down to fine art using impatient studio models? William Wegman, perhaps?
MFDBs have far more use than landscapes Andrew, for starters they are compatible with technical and view cameras, then, they retain colour information better and do so even in the darkest of areas, even more, their colour is more accurate and its gradations are more "stable" than DSLRs… there are more to say, but lets concentrate on your POV… From that POV then (yours), one should get an MFDB if what it gets from it, he cannot get from his DSLR (but needs to add it in his photography) and vide versa... Well, I totally agree! That's what was happening up to now with Ccd MFDBs and Cmos DSLRs… Now, the new back (IQ250) comes and suggests to add DSLR advantages into MF…. There are two questions that now have to be answered: 1. Are those qualities of interest for an MF user, since he already has them with his DSLR? and… 2. Have the traditional qualities that one wants an MFDB in the first place, been retained? ….lets wait and see, it seems that there will be more backs coming from all MF makers that will be using the same sensor.
 

Andrew Molitor

New member
No, it's not that I want DSLR features particularly. Its that the use cases in which spending $25,000 or more for a digital back makes sense are quite small, as I said.

Not non-existent, but quite small.

Being able to use it with wiggles is certainly nice, but that doesn't exactly explain Hasselblad. The argument appears to be that, for the low low price of about $30,000 I can avoid the trouble of stitching together pictures from my D3200, AND I get slightly better color fidelity?

I'm pretty sure that if I stick a 200mm lens on the D3200, and stitch myself up a 200 megapixel picture that contains, say, a roughly standard-lens field of view, and the downsample that to 50 megapixels, you're going to have an extremely hard time showing any measurable or perceptible differences in image quality, or image characteristics, in any particular dimension.

The cost for this setup is about $27,000 less, and I have to spend a few minutes in photoshop for each picture.

There are certainly cases where saving a few minutes per picture is, eventually, worth $27,000, especially when you add to that things like robustness of gear, compatibility with legacy equipment, and so on. I get that.

All I'm saying is that the use cases where it makes sense are extremely slim.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Well, Andrew,

That $27,000 ticket is hard to justify for me too. But why look that far? The Pentax option is really worthy of consideration. The body is just $7,000 with cents change! Add in a Pentax-D FA 645 55mm f/2.8 AL[IF] SDM AW Len for an extra $1,1200! The 90 mm Macro costs $4500. So far, enough for all my work, the total is $12,700. For the luxury of an ultrawide, I could add their Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens (~ 19.5mm Lens in 35mm terms), rounded aperture blades for smooth Bokeh and inline Filter Design for my landscapes and architectural passion at $5,000 and still not get above $17,700! Note that most of the money has been spent on long lasting superb optics, not on a short life sensor!

Overlapping adjacent fields at 200mm? I've been doing that, except with the Canon 1D Mark II, 8.2 MP and a 70-200mm 2.8 L IS lens and stitching separate characters into one composite image. I couldn't do that with MF so easily as one person plays them all. Still, with MF, I'd imagine doing the work with different actors and so get the job done much faster, with better cooperation between the figures and I'd be happy.

I have hesitated to make the jump to MF with CCD sensors as I have not enough experience with that magic to make me feel that CMOS can't do just as well. I appreciate the concept of color being more smooth right down to the shadows, but I have always felt that it hardly matters artistically. Today, noise reduction makes this issue almost mute, unless one is determined to pixel peep with a magnifying glass at 5 cm!

What is going to be true is that higher bit depth images should be more resilient to strong changes in color and shading in processing. If I did have such a MF camera, I'd love it and never look back.

Asher
 

Jerome Marot

Well-known member
Leaving the price aside for a moment, there could be many reasons to be interested in a MF camera. Let me list a few.

First: they are very nice machines. The viewfinder is a joy to use. If taking pictures is a hobby, why not treat yourself with the suavest conditions to experience it?

Second: if your interest is landscape and if you want to print bigger than 24" / 60 cm high, 24x36 will show its resolution limits as explained in a previous post. Your options are either stitch or use MF. Stitching means you need a panorama head and tripod, which will negate the weight advantage of the smaller camera. A camera with a leaf shutter (Hasselblad) will be a plus.
Keep also in mind that stitching is not possible with all subjects: for example anything with a body of water and the waves will never stitch perfectly.

Third: if your interest is portrait or fashion, MF has definite advantages. A leaf shutter will sync at 1/800s allowing strobes to overpower the sun. The increased resolution makes retouching easier. MF lenses, being used at slower apertures, have usually better bokeh transitions. The colours and highlights are optimised by the manufacturers, since this is one of their selling points.

But we should also not forget the disadvantages of a MF camera:
-they are slow to operate and conveniences that we take for granted in mainstream cameras may not be available (e.g. AF with many points or advanced metering)
-they are heavy and bulky
-the lenses are even heavier and bulkier. Zooms are not the norm, so you need a collection of large and massive primes.
-these primes are slow. f/4 is normal as a max aperture.
-none of the crazy ultra-wides or super tele of 24x36
-you may want a tripod if you want to enjoy the full resolution (and that tripod can only be light if you use a leaf shutter)
-max shutter may be as low as 1/800 (on leaf shutters), max iso may be as low as iso 400.
-and probably a few dozen disadvantages I forgot.

Note that MF cameras exist as film and as digital cameras. Some can even do both. Film only ones are quite cheap for the amount of metal you get. Digital less so, but can be bought second hand.
 

Asher Kelman

OPF Owner/Editor-in-Chief
But we should also not forget the disadvantages of a MF camera:

-they are slow to operate and conveniences that we take for granted in mainstream cameras may not be available (e.g. AF with many points or advanced metering)
-they are heavy and bulky
-the lenses are even heavier and bulkier. Zooms are not the norm, so you need a collection of large and massive primes.
-these primes are slow. f/4 is normal as a max aperture.
-none of the crazy ultra-wides or super tele of 24x36
-you may want a tripod if you want to enjoy the full resolution (and that tripod can only be light if you use a leaf shutter)
-max shutter may be as low as 1/800 (on leaf shutters), max iso may be as low as iso 400.
-and probably a few dozen disadvantages I forgot.

Note that MF cameras exist as film and as digital cameras. Some can even do both. Film only ones are quite cheap for the amount of metal you get. Digital less so, but can be bought second hand.

Jerome,

An excellent analysis!

But allow me to go back to the case of the Pentax 645D. According to nick Devlin, here in a Luminous Landscape first Look Review, has the opinion that the camera is in practice not heavier than any professional DSLR, and he can hold it 8 hrs a day over his shoulder with no problems of weight.

It has multiple focus points, albeit clustered nearer the center of the field. It also has a 19mm focal length equivalent wide angle lens and upper class autofocus, with a few caveats for some long lenses.

In fact, the camera came out ahead of the PhaseOne/Leaf-Mamiya or Hasselblad choices by virtue of photographer savvy layout and usability. Any 20% increase in MTF of the competing systems were not important as the sheer fluidity of use.

That's pretty amazing from a website where, if they were sleeping and I'd nudge someone, I'd wake up the entire Phase One sales team!

Asher
 

Jerome Marot

Well-known member
It looks like you are very tempted to get a 645D, Asher. Is there any rational reason why you would not get one, then?
 

Asher Kelman

OPF Owner/Editor-in-Chief
Jerome

You're intuitive, LOL! I am looking to see if Ricoh Pentax is going to take the next step and update the sensor. That's #1 on my concerns. But the second matter is whether or not there's an AF leaf shutter option for taking portraits outdoors and using a fast shutter speed at f 4 for limited DOF but then overwhelm the ambient light with a lightweight reasonable to carry strobe.

I have discovered some nice LS lenses but have no idea if they work in the modern 645D.

I also wonder what Ricoh's plan's are, as after mergers, lines that don't carry their weight get axed. So it would be great to have some leaked news!!

All things being equal, I'd trust Pentax, but right now, who knows?

However, if money was no object, it would be Phase One.


Asher
 

Asher Kelman

OPF Owner/Editor-in-Chief
I'll hold out a little longer! Unfortunately, a lot of the good stuff is disabled. So, for example, it appears as if one has to manually focus and then there's no exposure compensation or bracketing programming usable. Essentially, one has a small and neat Large format camera with 1/500 sec leaf shutter in the Pentax 645D with a LS lens. So if one is comfortable with these restrictions, there would be no issue.

Asher
 

Asher Kelman

OPF Owner/Editor-in-Chief
BTW, I just read on LL that "We can also expect at least two other medium format back and camera makers to adopt this same sensor, though at this point we don't have any firm information on what their time-table's might be like."

Well the Sony 50MP sensor is already matched to Phase One and Hasselblad so what two companies are there left. It seems that one would be Leaf, as they are really the Israeli sister of the Phase One by marriage, and then what else but the new Pentax I've been expecting!

So, if that's true, and Ricoh-Pentax are indeed on the ball, we might expect a 50MP CMOS before the end of this year. Now I was expecting a 60MP CCD sensor, so it will be interesting to watch the competition unfold!
 

Jerome Marot

Well-known member
The Pentax option is really worthy of consideration. The body is just $7,000 with cents change! Add in a Pentax-D FA 645 55mm f/2.8 AL[IF] SDM AW Len for an extra $1,1200! The 90 mm Macro costs $4500. So far, enough for all my work, the total is $12,700. For the luxury of an ultrawide, I could add their Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens (~ 19.5mm Lens in 35mm terms), rounded aperture blades for smooth Bokeh and inline Filter Design for my landscapes and architectural passion at $5,000 and still not get above $17,700! Note that most of the money has been spent on long lasting superb optics, not on a short life sensor!

Considering what you wrote (e.g. central shutter and flash) and what pictures you take, you may actually be more happy with an old H3D-50, 80mm, 120 macro (doubles as a portrait lens) and 28mm. Or even an H3D-31 or H4D-40 if you need better low light abilities at the expense of less wide-angles. All this may even be cheaper than the Pentax.
 
Second: if your interest is landscape and if you want to print bigger than 24" / 60 cm high, 24x36 will show its resolution limits as explained in a previous post.
Lets not be dogmatic about things… I believe that this forum should avoid questionable statements that remind viewers of similar posts that are made on other forums...
 

Asher Kelman

OPF Owner/Editor-in-Chief
Second: if your interest is landscape and if you want to print bigger than 24" / 60 cm high, 24x36 will show its resolution limits .

Well, Jerome, that also applies all the MF sensors if one is crazy enough to want to print 6ft high and still be able to view critically at 12" to 15" or even 25"! I'm doing the practical thing and getting files from a number of sources and will print selections at an appropriate magnification to give me a personal feel of what can be expected. It might be that a 40, 60 or 80 MP back works just fine, but it could also be that I should use a Canon 6D for planning and then shoot with 8"x10" with film. I don't have enough hands on experience with the MF files to know how they enlarge for full length portraits akin to Andrey Yakovlev's work here, but without the porcelain skin which is obviously less demanding. I'd actually like enough detail to have at least something of the life-like presence of images by Richard Learoyd, although he has a single sheet of full length Cibachrome positive paper for his work!

Asher
 

Jerome Marot

Well-known member
Asher, when I say 24" viewed at 12", I don't mean 6 feet viewed at 12" and when I say landscape, I don't mean portrait. And I referred to a previous post, which is #23 in this thread.

Theodoros, my statements are only questionable in the sense that you ask questions about them.

Now, I am afraid that I won't have anything to add to this thread. Good night.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Asher, when I say 24" viewed at 12", I don't mean 6 feet viewed at 12" and when I say landscape, I don't mean portrait. And I referred to a previous post, which is #23 in this thread.

Jerome,

I hoped for your input on scaling that up.

Friendship,

:)

Asher
 
Well, Jerome, that also applies all the MF sensors if one is crazy enough to want to print 6ft high and still be able to view critically at 12" to 15" or even 25"! I'm doing the practical thing and getting files from a number of sources and will print selections at an appropriate magnification to give me a personal feel of what can be expected. It might be that a 40, 60 or 80 MP back works just fine, but it could also be that I should use a Canon 6D for planning and then shoot with 8"x10" with film. I don't have enough hands on experience with the MF files to know how they enlarge for full length portraits akin to Andrey Yakovlev's work here, but without the porcelain skin which is obviously less demanding. I'd actually like enough detail to have at least something of the life-like presence of images by Richard Learoyd, although he has a single sheet of full length Cibachrome positive paper for his work!

Asher
Well, obviously printing quality has to do with viewing distance, a photograph is not exactly scientific material for us to study its print quality, but rather the photographer chooses the printing size depending on the impact he wants to create… It's all included in the visualisation process IMO…

Still, you are right in saying that its important to have an excellent capture combined with great lens/sensor combination, if the above is satisfied and one masters the technique of printing, diminishes all artefacts that can influence the print and forbids "automatic" sampling from having a "mind of its own", I would say that provided that there is a high quality sensor combined with a good lens that does justice to the sensor, one can have a great print at 72ppi with my printer (epson 9900) or at 75ppi with Jerome's printer… This of course means that any sensor above 16mp and of 35mm film equivalent size and above, can print great at more than a meter in the smaller size of the print… which of course leads to the conclusion that sensor resolution should be a secondary priority of choice in our times and that it's best for constructors to concentrate on improving per pixel characteristics on sensors instead of keep "fighting" against each other in a pointless "megapixel war".
 
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