I agree with your first statement about 6x7 cameras vs digital. But
your second statement (that it would take stitching 100+ digital images
to equal a 6x7) is grossly overstated. The resolution of a 6x7 is
limited to the resolution of the film available. Apart from Kodak
Technical B&W the resolution of color and B&W film is limited to 200
line pairs/mm (for very high contrast targets). If we equate that
resolving power to a digital sensor an equivalent digital sensor would
need 400 pixels/mm or 400 x 60 = 24,000 on the short size and 400 x 70 =
28,000 on the long side for 672,000,000 or 672 MP.
Mamiya makes an 80 MP digital back for medium format cameras with image
size 7,752 x 10,320 pixels. Assuming a very conservative 30% overlap
for stitching this could be accomplished with a 4x4 pattern and would
actually make a slightly larger image than the 6x7 film image since the
aspect ratio of the digital image is different at 4:3.
Certainly not as easy as taking a single 6x7 film image but 100+ images
is way out of bounds. Also, the dynamic range of the medium format
digital (12.5 stops) might give the film some stiff competition. Also,
choosing such high resolution film would limit the film's ISO to 25... a
very severe penalty in actual usage. Choosing higher ISO films (say
400) would cut the film resolution by a factor of 2 and the equivalent
MP count by a factor of 4. Then it would be 168 MP vs 80 MP with the
digital still having a dramatic advantage in available ISO range.
Chuck Norcutt
On 11/3/2014 9:16 AM, Sawyer, Edward wrote:
There isn't a digital camera made that can equal a Mamiya 7 ( or most 6x7 film
cameras). It Would take multiple stiching of 100+ digital photos to even come
close, and even then would still be inadequate in several ways.
On Nov 3, 2014, at 6:16 AM, "olympus-request@xxxxxxxxxxxxxxxxx"
<olympus-request@xxxxxxxxxxxxxxxxx> wrote:
OM] Mega Pixel equivalent of medium format negatives
Message-ID: <54565B5D.2020902@xxxxxxxxxxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Here is a question attributable to just mild curiosity.
I have scanned several 6 x 7 colour negatives taken with a Mamiya 7 II
medium format rangefinder.
At the most extreme size, some of the 16 bit/ch TIFF files are 528,000
kb each.
If one wanted to generate a similarly sized TIFF file from a digital raw
file what would the megapixel rating have to be of the camera
--
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