36 Megapixels vs 6×7 Velvia

Uses or users? I still need 5x4 for my usage. I'll admit that that colours my views on miniature formats (and when I started seriously in photography, the "official" definition of "miniature" was anything less than 6x9 (in practice).

The post above was the theory; the paragraph above my practical needs (or "wants" if you prefer).:D
 
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You haven't finished your story Stephen and..........................................

Anyway unless you have worked in the Kodak or Zeiss labs etc , I would say nobody here has seen everything on a 35mm colour\B/W neg..sure you can drum scan to a tiff but does a £750 monitor still show everything. I would suggest the colour\BW neg has somehow to be copied to positive without scanning (maybe transferred to a special pos film) , then use an excellent projector lens to project the neg\pos onto something suitable and then you would see everything.
 
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Copying will always degrade slightly. The simple answer is really old hat - a microscope.

A monitor - even a cheap one - is still a digital device and will show everything (in terms of details, even if the colours are wrong) if you display the image large enough. I'm assuming you can use something like Photoshop.

All this isn't of any practical relevance to me, though. All that matters is the quality of a print at A2. And hopefully, enough of it to let me go larger. And, before anyone asks, I view prints like a normal person, not a photographer - I don't use a calculator to take account of the degree of enlargement and then make sure I'm at the correct viewing distance. I view them like one of the unknowing, unsophisticated viewers of the early Daguerrotypes - oh golly, the detail goes on forever - what can I see if I use a magnifying glass? On this basis, 6x7 fails, but it's fine for A3.
 
Absolutely not! In so many different ways. But that would be another thread.
 
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StephenM said:
Just going back on topic for a moment - sorry.

Prompted by an earlier post, I recalculated the resolving power of a 36 megapixel sensor. Taking the pixel size of a photo from a Sony a7r, and assuming that the sensor size was 36mmx24mm (this won't be true - not even film frames are necessarily the "stated" size), and assuming that the pixels had no space between them, then there were 204 pixels per mm in both directions. Before tearing into this, note that the assumptions are actually not quite true; but it gives a reasonable starting point.

Now on to the second half of the original comparison. Film resolution is normally quoted with caveats as to subject contrast. The resolution of Velvia 50 (according to Fuji's data) is 80-160 lines per mm depending on the contrast. Set this against the 204 lines per mm of the sensor, the digital wins. In 35mm size. Go up to 6x7, and we have rather more lines resolved (the sensor will be 204x36 in the long side (7344), the film (say) 120 x 69.5 (Mamiya RZ67, Mamiya's figure) in the long side (8340).

I'm fully aware that this is less than the whole story, and there's the massive practical problem of exploiting the film fully. And that there are massive assumptions as to what the lenses can resolve, how it impacts on the overall performance of the system, the effects of the Nyquist limit etc. But it is something to ponder.
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There is the effect of Bayer layout on the image, while film doesn't have that particular issue, so on some stuff its actual resolution will drop *foveon sensors would suggest Ayer loses about half the info on average
 
The Bayer array means that you "average" four pixels into one, certainly; but I was under the impression that this was allowed for in the megapixel rating. After all, I get about the 36 megapixel figure by multiplying the short and long dimensions of the frame from a Sony a7r photo. The design of the microlenses can influence the resolution; but as I said, my back of an envelope calculation only established the absolute maximum, not the actual resolution.

What film does have as an issue is that the grains the form the image are suspended in an emulsion in three dimensions, unlike a two dimensional sensor; so any image forming light that mainly hits one grain will also hit the edge of any underlying grains that overlap the primary one. This will tend to make the image less sharp - but should be allowed for in the manufacturers' figures.

For some reason, digital camera makers are reluctant to release the basic information on their products that film makers regard as important for the user to know.
 
Yeah they are allowed, and foveon is fairly unique, so its been a non issue, but theres a big difference in detail between the two
 
ChrisR said:
There is a US startup CineStillFilm that has a few converted kodak motion films available, and there's also a Lomography version, I think (Cine200). If they can do it, maybe Kodak Alaris could too... of course, they'd have to want to and not assume that everything's perfect!
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CineStillFilm now have some European distributors, including West End Cameras and First Call Photographic. I'm hoping they make some more of the bwxx stock soon!
 
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