Actually, we need even more resolution.

[jerome_m]

(Tongue in cheek mode on...)

I am fed up with people criticising MF cameras and arguing nobody needs that many pixels. I had a look at fine art inkjet printers. These print on roll paper and come in width up to 60" (150cm). Using the standard 4x3 aspect ratio, they would print an image sized 60" x 80" (150cm x 200cm).

The printers have the same linear resolution than the smaller inkjets, hence they need to be fed the same ppi. Native ppi is something like 300-360 ppi.

300 ppi for 60" x 80" is 18000 x 24000 pixels, 432 million pixels. Anything less is a waste of a perfectly good printer.

[Manoli]

You exaggerate,

We're not arguing about the pixels, we're arguing about the format.
You need all 432 million pixels, you just don't gain an advantage from MF - 432 with a 24x36 sensor is fine.

Anything less and you're in the P&S domain.

[Torbjörn Tapani]

That sounds about right for a 24x36 sensor. I think we would be  limited by the glass at that point.

[BernardLanguillier]

It is available today and called stitching!

Cheers,
Bernard

[ErikKaffehr]

Hi,

What I have seen I would say 200 MP would be ideal on full frame 645.

At 6.8 microns I see a lot of aliasing that goes away at f/16. So for aliasing free rendition we would need 3.4 microns at f/8.

If we assume 54 sensor and 5/4 ratio we would have:

54 / 0.0034 * 43 / 0.0034 -> 200 MP

So, this would assume shooting at f/8.

Shooting wider apertures, with the best lenses, even more resolution would be useful.

Best regards
Erik

[Manoli]

Bernard,

Please try and understand that stitching may be an option for you landscape boys, but I can't stitch when I'm shooting Natasha Poly - and even if I could, editors wouldn't accept it and my tethering software even less.

So 432 million it is - native !

M

[jerome_m]

Well... 432 million pixels on 24 x 36 mm implies pixels of 1.33 µm (cell-phone size...). 432 million pixels on 53.7 x 40.4 mm implies pixels of 2.24 µm. I am pretty sure that the second one gives a more usable aperture for the diffraction limit.

[Chairman Bill]

... when I'm shooting Natasha Poly ...

I suspect I'd probably forget to even check that there was a memory card fitted, let alone be worrying about the resolution

[eronald]

Like all good satire, this is close to the truth. My first digicam was 640x480 pixels, now we are at 80MP, I am quite sure we will get to 500MP in the reasonable future.

Edmund

(Tongue in cheek mode on...)

I am fed up with people criticising MF cameras and arguing nobody needs that many pixels. I had a look at fine art inkjet printers. These print on roll paper and come in width up to 60" (150cm). Using the standard 4x3 aspect ratio, they would print an image sized 60" x 80" (150cm x 200cm).

The printers have the same linear resolution than the smaller inkjets, hence they need to be fed the same ppi. Native ppi is something like 300-360 ppi.

300 ppi for 60" x 80" is 18000 x 24000 pixels, 432 million pixels. Anything less is a waste of a perfectly good printer.

[Torbjörn Tapani]

Well... 432 million pixels on 24 x 36 mm implies pixels of 1.33 µm (cell-phone size...). 432 million pixels on 53.7 x 40.4 mm implies pixels of 2.24 µm. I am pretty sure that the second one gives a more usable aperture for the diffraction limit.

If you put it like that then it's feasible. Samsung could do it today. I want the 400 mpix landscape version NX800E :-)

[ErikKaffehr]

Hi,

Jim Kasson looked at it in great detail and I guess he found that something like 2.5 microns were needed for what he called balance performance on the Otus.

The problem with small pixels is that they will look very soft at actual pixels. They also may need a good downscaling algorithm. Epson printers go to 720 PPI resolution native. The 2.24 microns would give you a 48.9 x 24.8" print on 720 PPI, which people with normal vision could study at 12.5 cm distance with a +8 diopter eyeglass.

But, seriously something like 3 microns would be a very good compromise between sensor resolution and lens resolution.

Best regards
Erik

Well... 432 million pixels on 24 x 36 mm implies pixels of 1.33 µm (cell-phone size...). 432 million pixels on 53.7 x 40.4 mm implies pixels of 2.24 µm. I am pretty sure that the second one gives a more usable aperture for the diffraction limit.

[jerome_m]

The 2.24 microns would give you a 48.9 x 24.8" print on 720 PPI

The object of this thread is to discuss 60" x 80" prints (150cm x 200cm) on fine art inkjets. The printers exist, they are readily available and cost less than the average MF camera (e.g. Canon imagePROGRAF iPF9400 or Epson Stylus Pro 11880). How are we going to feed them with adequate data? There is no adequate camera on the market today.

OK: we can stitch. That is cumbersome: how many individual pictures do we need from a lowly camera like an IQ280 to feed the printer?

As eronald noted, this post is satyre, but is based on truth. The printers exist. I believe that people like Andreas Gursky use them to great success. Actually, "Rhein II" is 190 cm × 360 cm (73" x 143") and is a chromogenic print (Lambda print), so it needs even more data. And there is a body of water right in the middle, which makes it extra difficult to stitch.

[Bart_van_der_Wolf]

The object of this thread is to discuss 60" x 80" prints (150cm x 200cm) on fine art inkjets. The printers exist, they are readily available and cost less than the average MF camera (e.g. Canon imagePROGRAF iPF9400 or Epson Stylus Pro 11880). How are we going to feed them with adequate data? There is no adequate camera on the market today.

Hi Jerome,

It doesn't depend on input pixels alone. It also has to do with the acuity of human vision, which is also depending on distance because we have an angular resolution capability of approx. 1 minute of arc per line in output, or 60 cycles per degree (generally corresponding to '20/20' vision as measured with the Snellen eye chart in US customary measure, '6/6' in SI units).

What that means is that depending on the viewing distance, all cameras can have adequate resolution, although the better ones allow to achieve that resolution in output that is viewed from a shorter distance, and can be magnified more before it breaks down. So as per your question about output of 60x80 inches, it can be viewed from different distances, and better input resolution will allow shorter viewing distances. All is easy to calculate with my Output Quality Calculator tool, and will also determine the consequences for DOF.

OK: we can stitch. That is cumbersome: how many individual pictures do we need from a lowly camera like an IQ280 to feed the printer?

From my tool:
1 IQ280 image when viewed at 100 inches distance (for a normal perspective impression), printed at 129.1 PPI
4 images (+some overlap) for close to half the viewing distance,
etc., etc.

Cheers,
Bart

[BJL]

Well... 432 million pixels on 24 x 36 mm implies pixels of 1.33 µm (cell-phone size...). 432 million pixels on 53.7 x 40.4 mm implies pixels of 2.24 µm. I am pretty sure that the second one gives a more usable aperture for the diffraction limit.

Only in that the 36x24mm format would require an f-stop of about f/2 or lower to control diffraction, while the 54x40mm could control diffraction equally at about f/3 and lower --- with each having the same pathetically shallow DOF when diffraction is equally controlled. So about 420 million of those pixels would be OOF and so wasted as far as resolution goes.

The larger format would have the lens design advantage of needing less low f-stops. For example:
- an 80mm lens for 54x40mm format that is "430MP sharp" at f/3
is probably an easier lens design goal than
- a 50mm lens for 36x24mm format that is "430MP sharp" at f/2.

But do either of these lenses exist?


The iron trade-of between DOF and diffraction means that these massive pixel counts probably need focus stacking with anything but distant landscapes that have no foreground needing to be in focus.
And as Bernard will surely remind us, when you can do focus stacking, you can probably to stitching too, and the lenses have a better chance of giving adequate resolution at those low f-stops.

[jerome_m]

It doesn't depend on input pixels alone. It also has to do with the acuity of human vision, which is also depending on distance

Nope. I want the public to be able to examine the print with a magnifier, mm per mm if needs be. Why do you think Canon and Epson make printers capable of fine art print on 60" / 150 cm rolls? The printers will sustain a linear resolution of at least 300 ppi on the full length of their bed. That is a feat of engineering and comes with a price tag, yet that price tag is smaller than your average MF camera. You want me to feed that miracle of technology with inferior data? Forget it.

Besides: if I limit myself to lower quality, there are even larger printers available.

The printers are there, I want to use them to their full potential. I want the public to watch the large picture from the distance, then move closer and closer and discover more and more details. Have you been to a gallery or museum presenting really large prints recently?

[jerome_m]

Only in that the 36x24mm format would require an f-stop of about f/2 or lower to control diffraction, while the 54x40mm could control diffraction equally at about f/3 and lower --- with each having the same pathetically shallow DOF when diffraction is equally controlled. So about 420 million of those pixels would be OOF and so wasted as far as resolution goes.

The larger format would have the lens design advantage of needing less low f-stops. For example:
- an 80mm lens for 54x40mm format that is "430MP sharp" at f/3
is probably an easier lens design goal than
- a 50mm lens for 36x24mm format that is "430MP sharp" at f/2.

But do either of these lenses exist?


The iron trade-of between DOF and diffraction means that these massive pixel counts probably need focus stacking with anything but distant landscapes that have no foreground needing to be in focus.
And as Bernard will surely remind us, when you can do focus stacking, you can probably to stitching too, and the lenses have a better chance of giving adequate resolution at those low f-stops.

Shallow depth of field is not necessarily a limitation for pretty large prints, as shown in this video: http://lectures.icp.edu/archive/videos/2011/Learoyd2011.html

[bjanes]

Hi,

What I have seen I would say 200 MP would be ideal on full frame 645.

At 6.8 microns I see a lot of aliasing that goes away at f/16. So for aliasing free rendition we would need 3.4 microns at f/8.

If we assume 54 sensor and 5/4 ratio we would have:

54 / 0.0034 * 43 / 0.0034 -> 200 MP

So, this would assume shooting at f/8.

Shooting wider apertures, with the best lenses, even more resolution would be useful.

Best regards
Erik

Roger Clark has published an interesting article that concludes that about 200 MP is necessary to have an image that can knock off the socks of a viewer in an exhibition gallery. This can be obtained with 4*5 inch film, but would require stitching with any currently available digital camera.

Bill

[jerome_m]

This can be obtained with 4*5 inch film

Hiroshi Sugimoto believes he needs 8 * 10 inch film for his massive prints. They sure look impressive.

He also needs a purpose-build enlarging room, special order of photo paper and an army of retouchers. But, yes, you are right: it can be done.

[Bart_van_der_Wolf]

Nope. I want the public to be able to examine the print with a magnifier, mm per mm if needs be.

Exactly my point, it depends on viewing distance, so yep.

Why do you think Canon and Epson make printers capable of fine art print on 60" / 150 cm rolls?

Two reasons, one is to allow nesting of many images on a relatively affordable length of paper/canvas/etc., an other is to produce wide format output in one piece, not necessarily at the same resolution of the multiple smaller prints. IOW, flexibility.

The printers will sustain a linear resolution of at least 300 ppi on the full length of their bed. That is a feat of engineering and comes with a price tag, yet that price tag is smaller than your average MF camera. You want me to feed that miracle of technology with inferior data? Forget it.

But you can. There is no obligation to feed it 300 or 360 PPI captured detail, especially when the viewing distancee doesn't require it. The added flexibility is that one can (not must but can) feed it lots of real capture detail, but that requires a lot of data and huge files.

The printers are there, I want to use them to their full potential. I want the public to watch the large picture from the distance, then move closer and closer and discover more and more details. Have you been to a gallery or museum presenting really large prints recently?

Yes, but I don't see the relevance. It you want to inspect with a loupe, and expect to see more detail (instead of the same detail but larger), then by all means shoot with a larger (virtual) sensor with more sensels. Stitching is a very viable way to increase input resolution for large output. It is also much easier than some believe, even with moving subjects (although they may require a bit more experience and post-processing).

Cheers,
Bart

[Bart_van_der_Wolf]

Hiroshi Sugimoto believes he needs 8 * 10 inch film for his massive prints. They sure look impressive.

Others have used bigger cameras ..., contact prints are much better than enlargements

Cheers,
Bart