Just 10Mp??? What was Leica thinking?

[jlw]

It is well-known that if a negative is good enough for A4 it is good enough for any enlargement, as the viewing distance will increase with the print size, making the net result about equal.

This "well-known" premise sounds like a good rule of thumb, but I'm not sure it's firmly founded enough to use as a basis for this entire technical presentation.

For example, it isn't the case for print publication. The reader is going to view a photo enlarged to fill a double-page spread at the same distance from which s/he views a small one-column photo.

 

[jaapv]

This "well-known" premise sounds like a good rule of thumb, but I'm not sure it's firmly founded enough to use as a basis for this entire technical presentation.

For example, it isn't the case for print publication. The reader is going to view a photo enlarged to fill a double-page spread at the same distance from which s/he views a small one-column photo.

That I will not dispute, shooting photo's for print is a whole different ball-game as the photog. must be familiar with, and allow for, the printing process.It is one of the things we must keep in the back of our minds, what we are going to do with our picture. For instance, in your example the effect of the DOF will be different as well.

 

[rvaubel]

Whilst I am at it. Viewing files on screen at 100% is a pretty pointless exercise. You need to look at the file at about 25% on screen to get an impression of what it will look like printed at 300dpi (300/72).

Gid

Good point, to approxiamate 300dpi, one would have to reduce the file to 25% at 1280 pixels across a 15" laptop. I recently purchased a laptop with 1680 resolution which is giving me nearly 130dpi. I find this more nearly replicates the print experience. There are subjective factors that make 130dpi on a LCD look like nearly doubly the resolution on paper. Anyway, I find 100% to be fine at a 130 pixel per inch on an LCD screen. At 50% it really seems sharp i.e. if I cant see it it doesn't exist.
For photographic uses, It seems to me that screen resolution should approxiamate print resolution as closely as practical.
One other note. When doing a percent reduction, use an even number divisor, as in 50%, 25%, not 66%. I may be full of it, but it seems those pixels liked to be divided neatly.

Your results may vary

Rex

 

[MarkM6]

Educational.

Educational.

Jaap,
Posts like yours make me keep coming back to RF Forums...

Thank you,
Mark

 

[Bob Ross]

I'm afraid there might be some flaws in your argument.

First, resolution is measured in line pairs per mm, meaning just that - two lines, normally black and white. To approximate two lines with discrete digital sensor you need 4 pixels (quantization theorem).

It was my understanding that a line pair, one black line and one white line, could be represented by two pixels. This seems to be the general use of the terms in discussions and articles on digital imaging. It also shows up in digital printing, with 300dpi equal to 150 lpi. I have read several discussions about thre and four pixels being needed, but they all end up coming back to two pixels.

 

[Socke]

It was my understanding that a line pair, one black line and one white line, could be represented by two pixels. This seems to be the general use of the terms in discussions and articles on digital imaging. It also shows up in digital printing, with 300dpi equal to 150 lpi. I have read several discussions about thre and four pixels being needed, but they all end up coming back to two pixels.

That`s what I have learned about prepress and screening. But there 1000lp\mm are equivilant to 300dpi with a dot being just a dot and anything from 4 to 64 dots needed to represent a pixel.
In germany I used a "48er Raster" for better newspaper and a "54er Raster" for magazin quality. We could get to the "48er Raster" with a 1200 dpi (not ppi) Laserprinter, which was quite an achievement in 1993 and it cost in A3+ not much less than a Phase One 22Mpixel back today .
48er Raster is 120 lpi and 54er Raster is 138lpi which was a stretch for the 1800 dpi Lasermaster laserprinter. Marketing promissed a 150lpi 60er Raster (actualy, they promissed a > 100 Raster), but the printers told me somethting else which usualy began with words like crap

 

[Bob Ross]

That I will not dispute, shooting photo's for print is a whole different ball-game as the photog. must be familiar with, and allow for, the printing process.It is one of the things we must keep in the back of our minds, what we are going to do with our picture. For instance, in your example the effect of the DOF will be different as well.

In the good old film days we either made prints or projected slides. Some who made prints even gauked at the grain with grain magnifiers.. With digital, more people are making prints on inkjet printers and very few are projecting, but rather viewing images on monitor screens. We still have the pixel/grain/noise gaukers doing the 100% thing.
I have found that the digital printing process is the great equalizer in the resolution comparison game. 300dpi is 5.9 lpm, about what our vision can handle from 10 inches. As I remember chemical color print paper can resolve 75 lpm, so digital printing is on the border of our vision, where the chemical print goes beyond. In digital printing the advantage of no grain narrows the film advantage in resolution. For people used to the print sizes from 35mm film, 10MP is going to be fine, even with cropping.

 

[Socke]

Inkjets go far beyond 300dpi, more like 2400 and some even 9600. With modern 6 or 8 colour printers and raster diffusion as well as wet in wet printing you get much more than what you know from old offset presses.

Why buy an Epson capable of 5400 dpi and then print at 300?

 

[Bob Ross]

I think you are confusing the print head resolution with the line step resolution. The print head resolution is what goes into making each dot and line step resolution lays down each line. My Canon S800 can print 600dpi when I want to make high rez postage stamps. It is sort of agreed that printing past 240dpi, doesn't produce enough visible improvement for the ink expended(HP tech paper). The author of Q-Image also has some interesting approaches to the contrary.

 

[ampguy]

less perfect than a cd?

less perfect than a cd?

that needs some qualification. same vinyl, and same cd? what if the CD of the album was sourced from a copy of the master tapes, or deteriorated master tapes? Or as many CD's are, suffer from bad EQ and mastering?

The limit of 10mp is often for price, and to not show deficiencies in lenses, which high mp sensors will show.

This has been the tendency of some posts around here... I've been crunching some numbers over the weekend, working from the other end, i.e. what is the biological resolution limit.
It is well-known that if a negative is good enough for A4 it is good enough for any enlargement, as the viewing distance will increase with the print size, making the net result about equal.
I postulated a 75x50 cm print, viewed at 75 cm distance. That would even tax film.
The finest detail the human eye can resove at that distance, for a relatively young person of say, 25 years old, is 0,25 mm.
We need, then, 4 points per mm. That makes 3000x2000 points, which is, obviously, 6 Mp. So 10Mp has plenty of reserve.

How does that compare to film? Well, normal 100 ISO slide-film resolves about 50 points/mm at 30% contrast transmission. That is just 1800x1200 pixels = 2.6 MP !!
Let's make the competition stiffer, use Technical Pan or Delta 100.
Those will resolve, used with an Apo-Summicron 90mm about 100 point/mm@ 30%.
Now we are talking! That means 3600x2400 pixels. Nearly 9 Mp. Very close to Leica's 10 Mp. But we needed the finest film and the best lens in the world to get that close.

But wouldn't more Mp's carry the M8 into the realm of medium format camera's? Not with a 1.33 crop sensor. The resolving power of the lens is, at 10Mp with a 1.33 crop, or 16 Mp with a 35 mm sensor, exactly the same as the sensors.So any increase in the number of pixels would necessarily involve reduction of the size. The only result would be that the same point projected by the lens would be picked up by more than one pixel, not creating any increase in resolution.

In terms of resolution sensors and lenses have reached the boundary of biological need. If we find one that we are happy with in terms of colour rendition, contrast and dynamic range, the only reason to"upgrade" will be mechanical, not electronic.

There is a myth that sensors do not have the dynamic range of film. That may still be true of the softest B&W film, provided they are developed accordingly, or with small second-rate sensors. In normal use however, a high-end sensor will render about 10 stops, which just happens to be the same as the number of zones in Ansel Adams' time-honoured zone-system. There is no way a normal slide film can better that.

There remains the issue of sensor noise. For one part I cannot understand that we accept grain in film as normal or even desirable, and will not grant sensors the same courtesy, on the other side sound engineers have been fighting noise for decades now, with some result, but it seems to have levelled out. I doubt there is much to be gained in that department.

Is this the death-knell of film then? I don't think so. There are - and always will be - artistic differences between the two media. I spent a lovely weekend listening to vinyl records - yes they sound nicer, albeit less perfect than a CD and they are still available, as are turn-tables and cartriges and tube amplifiers, and my daily car has been pushed into second place by my TR4 these summer days, which, even if cars have evolved dramatically the last 40 years, drives as well, but with more character. Morgans are still being sold.

Will the M8 turn into a vintage digital camera over the years? It seems to be fairly certain.

 

[sf]

jaapv : I like your thread opening. Well said. Very thoughtfully written.

Perhaps the 2.6MP is slightly off. . . but that is really of no consequence given your apparent intent.

After spending a weekend admiring my cousin's Casio EX-Z750, and printing very decent 8x10s from it, I'm sure the Leica will be a totally amazing camera.

 

[Rich Silfver]

After spending a weekend admiring my cousin's Casio EX-Z750, and printing very decent 8x10s from it, I'm sure the Leica will be a totally amazing camera.

I hope the digital M-Leica will be an amazing camera as well....but, and I may be missing something here, what does the Casio EX-Z750 have to do with how you reached the conclusion that the Leica will be an amazing camera? (Handing, build quality, image quality, size/weight, etc)

 

[Harry Lime]

There is a myth that sensors do not have the dynamic range of film. That may still be true of the softest B&W film, provided they are developed accordingly, or with small second-rate sensors. In normal use however, a high-end sensor will render about 10 stops, which just happens to be the same as the number of zones in Ansel Adams' time-honoured zone-system. There is no way a normal slide film can better that.

Digital is better than slide film, but still falls short of color negative. At least that holds true for anything short of a digital MF back and even then I would have to see it with my own eyes.

While it is true that most digital cameras like the Canon 1D mk II will see 10-11 stops from black to white, they do not have the exposure latitude of film negative.
The closest thing out there is the Fuji S3 and even it falls short.

I really wish the manufacturers would start to back off from the megapixel armsrace and instead concentrate on solving this problem. My guess is we will see some serious movement on this front over the next 5 years.

 

[Socke]

I think you are confusing the print head resolution with the line step resolution. The print head resolution is what goes into making each dot and line step resolution lays down each line. My Canon S800 can print 600dpi when I want to make high rez postage stamps. It is sort of agreed that printing past 240dpi, doesn't produce enough visible improvement for the ink expended(HP tech paper). The author of Q-Image also has some interesting approaches to the contrary.

Interesting, the HP Indigo Press3050 is sold as 812x812dpi/230lpi resolution and 4000 A4 pages an hour.

The printer I work with got one because it's better for colour prints than the Xerox DocuColor 8000 he has for less demanding jobs.

 

[varjag]

It was my understanding that a line pair, one black line and one white line, could be represented by two pixels.

Unfortunately it can't. Quantization/Shannon sampling theorem tells us that the sampling interval (in our case, pixel size) should be choosen to be less or equal to half of the smallest interesting detail in image. I.e. you need 2 pixels to represent a line, and 4 pixels for pair of adjacent lines of same width. Quantization theorem is a fundamental part of information theory and has major consequences for signal transmission, sound encoding (e.g. you need 22KHz to capture typical 11KHz spectrum of human voice) and other everyday practical applications.

 

[majid]

Plus, I like to make fiber prints, so digital makes that impossible.

You could make contact prints using Dan Burkholder's technique. I am sure someone could come up with a filter to turn grayscale images into higher-resolution black-and-white images replicating the look of certain films, but the market is too small to make it viable.

I myself am in the camp of those wanting fewer, lower-noise pixels. I tried the R-D1 with my Summicron 50 and Noctilux, and was blown away by the quality, far superior to my Rebel XT, despite the latter sporting a Canon 35mm f/1.4L

 

[jaapv]

Digital is better than slide film, but still falls short of color negative. At least that holds true for anything short of a digital MF back and even then I would have to see it with my own eyes.

While it is true that most digital cameras like the Canon 1D mk II will see 10-11 stops from black to white, they do not have the exposure latitude of film negative.
The closest thing out there is the Fuji S3 and even it falls short.

I really wish the manufacturers would start to back off from the megapixel armsrace and instead concentrate on solving this problem. My guess is we will see some serious movement on this front over the next 5 years.

And how are you going to show your more than 10 stops exposure latitude in print, may I ask

. That would be by dodging and burning. Have you ever tried to do that to a colour print? I did-never again.

Your colour lab certainly won't do that for you - or maybe for a horrendous price and not to your taste.

With a digital file it is pretty easy to do your own darkroom work.So scan your negatives and do it then. You'll find that if you scan colour negative film it will go lumpy and will not reach the quality of either slide film or a digital file. By shooting RAW there is no way a shot with a digital camera is inferior to film in this respect. Having said that, latitude for mis-exposing is always welcome

 

[sf]

I hope the digital M-Leica will be an amazing camera as well....but, and I may be missing something here, what does the Casio EX-Z750 have to do with how you reached the conclusion that the Leica will be an amazing camera? (Handing, build quality, image quality, size/weight, etc)

Yes, there IS a weak link in my logic there. Of course, I don't think my failure on that line is of any real consequence (or value as a discussion point) here. . . but :

I guess I was pleased with its performance, low light as nice as I've seen, and its other handling characteristics, and got to be momentarily hopeful for the future of digital. A larger sensor, faster manual controls, and a Leica M style body would lift things to a higher level. I dislike the heavy, bulky, loud nature of DSLRs, and never really played with a smaller, quieter digicam before. The Casio taught me alot about what I was missing with the D70. And what I should look forward to in future digital rangefinders. The M8, for instance.

 

[jaapv]

that needs some qualification. same vinyl, and same cd? what if the CD of the album was sourced from a copy of the master tapes, or deteriorated master tapes? Or as many CD's are, suffer from bad EQ and mastering?

I don't even think a lot of my Lp's have ever been issued on Cd.... The best records I have are direct cut, I also have some pre-issue demonstrators. Those are indeed very-very good. I doubt any Cd I know reaches that level of presence and dynamics.

 

[Harry Lime]

And how are you going to show your more than 10 stops exposure latitude in print, may I ask

.

Well, according to that logic we shouldn't be shooting anything but slidefilm.

With a digital file it is pretty easy to do your own darkroom work.So scan your negatives and do it then. You'll find that if you scan colour negative film it will go lumpy and will not reach the quality of either slide film or a digital file.
By shooting RAW there is no way a shot with a digital camera is inferior to film in this respect. Having said that, latitude for mis-exposing is always welcome

Trust me, over the past 15 years I have made a very good living as a professional, manipulating more scanned film and digitally captured images than than I care to admit in polite company. We are not there yet, but it's just over the horizon.

Digital certainly has the edge in the noise area, no argument there, but it still has a way to go in terms of exposure latitude. Note how I say latitude, not over all exposure range.