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A question of judgement

Discussion in 'General Equipment Chat & Advice' started by Brian, Aug 22, 2001.

  1. Brian

    Brian Venerable Elder

    Lots of debate re the old 'Is Digital better then 35mm' Well from what I have seen the answer is that one day it might be but it's a long way off.

    On one hand we have claims that 20"X32" prints can be produced digitally that are the equal if not better then 35mm film.

    Recently Calumet held a seminar re professional equipment and the general opinion that up to 12"X16" digital could hold its own. This was using large format digital gear that cost more then most peoples houses.

    Today I see that Damien Demolder is testing the new £7000 Kodak, 6M pixels and a 3032x2008 CCD size. I find his conclusion interesting, I quote." So the question is will 6million pixels be enough to replace 35mm? And the answer is no. If you only print at 5"x3" and use the image at 600PPI, then you have film quality...." He continues," Film quality to me means printing at 600PPI and getting a 10"x 8" print-for the moment. And from looking at this camera I want at least 12 million pixels".

    So I think that anybody holding back should make the choice, otherwise the wait might prove very long. Or am I missing something, apart from grey cells?

    Slimey.
     
  2. phil

    phil Well-Known Member

    As I have said in previous postings digital quality is not just about the number of pixels but more importantly their size, density and light response (particulalrly at ambient temperatures) To equate a digital sensor to a larger format camera one requires a sensor of the same size with pixels of the same size or smaller (if considering read off channels) as halide crystals!!!

    And we ain't got that yet!

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  3. Brian

    Brian Venerable Elder

    But Phil the remark I made about large format digital was to illustrate that the users of such did not consider that their equivalent, i.e. large format digital equipment was at this time as good as traditional film.

    The main part of my posting was to report the findings from an A.P. test review conducted by a very well respected reviewer, Damien Demolder. I am sure you are right re your comments, but a man of this reviewers experience would surely have taken all these items into consideration.

    Slimey&lt;img src="/img/wwwthreads/smile.gif"&gt;
     
  4. phil

    phil Well-Known Member

    Are you sure - nothing against Damien - but not many people consider the architecture of the sensors but just pixel count instead! In fact it would be better to quote sensor details as pixels per unit area as this is more informative !!! Its like talking about population denisiies between the UK and France there's about the same number of people but they are much more spread out in france cos its bigger!!!

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  5. Brian

    Brian Venerable Elder

    Phil, lets forget the pixel thing for a moment, it doesn't really matter. What Damien is saying that in his opinion the result of printing up to 5"x3" using a very very expensive camera with the highest technical specification yet, with the largest CCD chip yet, can only equal traditional 35mm up to 5"x3", after that it cannot compete. My knowledge re digital is less then nothing its just the different claims which are confusing. I realise that this is only Damiens opinion, but the disparity re the quality of digital seems to be enormous.

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  6. phil

    phil Well-Known Member

    But the pixel thing is the point What Damien has said from what I gather from your post is that beyond 5x3 the pixel size becomes notocable and therefore resolution is lost In the same way as an over enlarged halide print will look grainy if blown up too big And therefore the limit is set by pixel size and density and to overcome the limitation requires more smaller pixels per unit area or a much bigger which requires less enlargment to the final image!

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  7. Brian

    Brian Venerable Elder

    Yes, basically Phil. What Damien is saying is that with Kodaks new state of the art digital camera it can produce photographic quality, i.e. 35mm film quality with prints no larger then 5"x3" after that no. The technical reasons that it can't match film are neither here nor there. My simplistic question is, why do some people claim digital to be as good or better then 35mm film and then a professional reviewer with a top of the range camera say's that it's not.

    To me the answer can only be the same as the title of this thread, "A question of judgement" In fact he continues the review by saying, and again I quote directly,"Film quality to me means printing at 600PPI and getting a 10"x8" print-for the moment. And from looking at this camera I want at least 12 million pixels".

    You suggest that more pixels are needed at a greater density etc. But Phil you are only giving the reasons why digital must improve to give traditional quality. You are probably right, but at this moment in time are we saying that Damien is wrong, or do we agree with him in suggesting that digital cannot compete re the final print with 35mm film?

    Basically what I am asking is how can we have on one hand people claiming digital is the equal to 35mm even with giant size enlargements and then a professional reviewer with the latest most highly specified camera stating that it is only the equal up to 5"x3", that is the question.

    Now don't shoot me I'm only the messenger.

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  8. TimF

    TimF With as stony a stare as ever Lord Reith could hav

    Surely some of this depends on the final output medium? If the aim is to produce a large exhibition print then digital still can not hold a candle to film. On the other hand, for repro in books (even on photo quality paper) digital IS now generally up to spec, if used with little or no compression. What advantage film has is lost in the photomechanical reproduction process.

    My 2p worth.

    Get out and get shooting!!
     
  9. Brian

    Brian Venerable Elder

    Of course you have made a valid point re photomechanical reproduction. You say digital can't hold a candle when it comes to 'Large Exhibition Prints' But Damien is saying that above 5"x3" it loses out to 35mm film. I don't know if I agree with him because I have seen very little output myself but the few 10"x8 which I have examined have seemed acceptable to me.

    Perhaps if Damien isn't too busy he might like to clear up this thread.

    Slimey.
     
  10. Reading

    Reading Well-Known Member

    10x8 at 600ppi is actually 28.8 Million Pixels if you do the math! Which is roughly a 4000ppi scan of a 35mm neg. Now most people are happy with 300ppi printing, which would be 7.2 million pixels. I reckon 6 million will be good enough for all but the MOST demanding enlargements, which would probably be done on medium format ideally anyway.

    What is holding me back is waiting for a FULL FRAME 35mm 6MP sensor at a reasonable price (and in Pentax mount). I would pay through the nose (perhaps still not £7000) for my ideal - but I would not pay what is currently stupid money for anything less!

    This is MY judgement.

    Damien seems to have bucked the current trend and actually talked some sense about digital vs film, even if his math was a bit out.
     
  11. phil

    phil Well-Known Member

    Firstly Brian I wouldn't shoot you, just put a ring of salt around you on the path!! Ha HA As for printing at 10x8 at 600ppi giving 28.8 m pixels is wrong its 29 m bits of printer dye. And each pixel will be made up of varying numbers of dye blods of the same colour, i.e 1 blob 4 blobs or nine blobs etc etc but still the pixel size and resolution stays the same however big its printed! You could make a bill board size image but each pixel would reproduce at a foot square each made up of 20m blobs of the same colour. It is true that with image analysers you can interpilate across pixels to yeild a sub pixel size resolution (aided by the fact that the pictures are handled as virtual hexagons and not squares) but I'm yet to see that in either colour or products for the home market!

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  12. Reading

    Reading Well-Known Member

    You seem to be talking Dpi or something.

    ppi is PIXELS PER INCH, and has nothing to do with blobs or whatever. Pixel size DOES vary with magnification, what doesnt vary is dot size on the printer (blobs to you).

    10x8 inch at 600 PIXELS PER INCH = 6000 x 4800 pixels = 28.8 million pixels.
     
  13. phil

    phil Well-Known Member

    So if you print with a standard digital camera with 3-m pixels where do the other 25 million come from? Perhaps you could define the word pixel for me?

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  14. Reading

    Reading Well-Known Member

    I have re-read your last few posts, and I still dont understand what you are on about here. What other 25 million? If you have got 3M pixels that thats what you have got unless you resize the image in which case the graphic program 'estimates' the extra pixels.
     
  15. phil

    phil Well-Known Member

    The original thread concerned printed pictures not ones on the screen although the same hold true. An enlarged pixel just become bigger its colour doesn't change ( a small red blob becomes a larger red blob be it on a page or screen) and no graphical program exists to perform the necessary interploation to do this. So until the pixels in you camera become smaller and more densely packed the final printed image will not improve beyond a change in its linear dimensions. Resolution stays the same!!!

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  16. David Stout

    David Stout Well-Known Member

    I haven't read Damien's report so I will rely on Brian's post as to what was said.

    Two points:

    1) I think Damien is falling into the well-worn trap of estimating what a 35mm frame should be in terms of pixels and claiming that anything less than this won't give 35mm quality. I do not feel that this is a valid exercise and neither does appear to be borne out in practice. I see no reference to 'actual' image quality just 'hypothetical' image quality.

    Besides, if he reckons that a 6 Mp camera is only good enough for 5x3" at 600 ppi then how does he derive that a 12 Mp camera will give him 10x8" at 600 dpi? My maths tell me he is going to need a 32 Mp camera to do this!

    (BTW - can anybody honestly tell me they can see a difference between a 600 dpi image and a 200 dpi image when printed on their computer printer? Try it and see - the only difference you will 'see' is that the 600 dpi image takes longer to print. If you think that your super new colour printer can do 1440 dpi or even 2880 dpi then think again - the marketing boys quote the mathematical product for all the inks so divide this figure by 6 if you have a 5 colour black printer. The printer driver 'throws away' any additional resolution beyond what the printer can handle. Same for scanners - who has a 1600 x 3200 dpi scanner? Do you think you can get rectangular pixels? No, the optical resolution is actually 1600 dpi. The 3200 dpi is a theoretical maximun on one axis only but becomes meaningless if the other axis cannot match this. It is marketing 'hype'. You might be able to scan a a higher dpi than this but this is interpolated resolution not optical resolution. So, let's separate myth from reality.)

    2) As far as Calumet is concerned, they might be right if they are talking about glossy magazine covers with MF or even LF quality that you could take a magnifying glass to. As amateurs, we are keen on quality but our criteria for 'acceptability' would be somewhat lower than the pro who is into large format. These guys would throw a Leica with a 50mm Summicron in the bin because the quality isn't up to it.

    What seems to be lacking is a sense of proportion. Even MF when blown up sufficiently large it will show grain. It seems that digital is unfairly subjected to greater critical scrutiny than film. Why? What have people got to fear?

    I have seen bad images from a Hasselblad. I have seen good images from a cheap point-and-shoot. I have seen poor digital camera images. Equally, I have seen really excellent digital images that you wouldn't know were digital.

    So what conclusion do I draw? Like any camera, the equipment alone doesn't guarantee that you get a good image. I don't just mean composition here - I mean technical quality. Understanding the limitations of the equipment and exploiting them to their full potential with sympathetic processing gives the best results. This applies to both conventional and digital cameras.

    If today's digital cameras are so bad in comparison to 35mm (as is the implication here) then why do so many professionals now use them? Why are digital camera sales on the increase?

    I could go on but I won't. All I would say is that anybody interested in digital should at least see a camera, use it and see what can be done with it. Prove it for yourself. Other people's opinions are just that. It's just that I would have thought that a reviewer for Amateur Photographer would have reviewed something on the basis of acceptability to an amateur photograher and not for high-end professional work.

    David
     
  17. Reading

    Reading Well-Known Member

    You seem to be missing the point - smaller pixels in camera or bigger sensor makes no difference, it all means MORE PIXELS. I think you need to try and understand the difference between dpi and ppi as what you are saying bears no relation to what people are saying to you.
     
  18. Brian

    Brian Venerable Elder

    Here you guys, all I was asking was that it is claimed on the forum that prints 20"x32" can be produced which equal those from 35mm negatives. On the other hand Damien using a camera with far higher specifications aimed at the top of the professional market states that anything over 5"x3" film has the edge.

    Phil, I think you and your salt cellar stink!

    Slimey /img/wwwthreads/smile.gif
     
  19. Reading

    Reading Well-Known Member

    At last, someone here talking some sense.

    While I dont totally agree with you about the acceptability below 6MP, I do think that Damien has missed the first part of the magazine title, although he would argue his article was geared to the user the camera is aimed at. At £7000 this is likely to be the professional so I can understand his viewpoint too, although he should at least state this in the review if that is the case.

    I like to get 300ppi prints, and as such 6MP is OK for 10x8 unless you want to do a lot of cropping, but I would like more for A3 or cropped prints.

    I definately agree with you that is not the specs of what you have got, but the quality of their implementation, and the way you use it that makes the picture.
     
  20. Brian

    Brian Venerable Elder

    David,

    The purpose of this posting was to try and work out where Damien was coming from. As you know I have some of your A4 prints, and I would say that they are of high photographic quality. I just don't understand where Damien gets his super high ideals from. It all smacks of a bit of cloud cuckoo land to me.

    Brian.
     

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