Digital BW, The Print

Steven,

I agree that the 4x5 should do better than what I obtained in this 
comparison.  Although, I'm surprised by your comments on the Fujinon 
240 A quality.  I purchased this lens based on the rave reviews in the 
largeformat photography forum and on Kerry Thalman's web site.  Mine 
seems to have about the same level of sharpness as my Rodenstock 
Sironar-S 135mm f/5.6, which is the only other lens I have for the 4x5. 
  The 240 gave the better focal length match to the 135 on the 10D so 
that is why I used the 240 for this comparison.  A few other factors 
that may be involved are wind (as affecting film flatness - there was 
some movement of the envelope during the 2 second exposure), possible 
focusing error, and scanner quality.  I added 3 more comparison images 
using the scan from a second negative shot at the same time as the 
first and this one seems to be slightly sharper, although I'd still 
give the 10D composite a slight edge in sharpness.  Both the 10D 
composite and the 4x5 scan produce very good 16x20 inch prints so in 
terms of the end product its' a toss up.

Carl
http://homepage.mac.com/scho/forweb/index.htm

On Dec 11, 2004, at 2:09 AM, Steven Karafyllakis wrote:

>
>
> Carl, very interesting experiment, it certainly shows the potential
> of the stitching technique. I must however point out that you have
> inadvertantly biased the results in favor of digital, by your lens
> choice. I own a  Fuji 240 A, and I consider it my very worst 4x5
> lens. In fact, I consider it to be one (small) step above coke-
> bottle grade glass. And Polaroid PN film isn't all that sharp
> either, at least I've never been able to get resolution comparable
> to sheet film out of it. Not to 'nitpick', but the 4x5 should have
> been able to do better!
>
> Steven Karafyllakis
>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
> <scho@m...> wrote:
>> Just to follow up on my previous post about stitching, I took some
>> comparison shots yesterday at a local waterfall with a 4x5 and a
> Canon
>> 10D.  Here is a side by side comparison of a stitched composite
> image
>> (18 frames (landscape orientation) in a 3 column by 6 row matrix)
> made
>> with the Canon 10D and 135mm f/2 L lens and a scanned (Epson 3200
> set
>> to produce a 16x2016 bit grayscale at 360 ppi) image from a
> Polaroid
>> type 55 4x5 negative, shot with a Tachihara 4x5 field camera and
>> Fujinon A 240mm f/9 lens.  Exposure for the 4x5 was 2 seconds at
> f/32
>> (EI 25) and for the 10D images 1/6 sec f/16 (EI 100).  The
> comparison
>> images are side by side screen grabs in Photoshop at 8, 25, 50 and
> 100%
>> of image size.  The 4x5 image is 83.6 MB and the stitched 10D
> image is
>> 80.1 MB and both are 16 bit gray. The 25% image is approximately
> the
>> appearance when the images are printed at 16x20 inches.  The
> stitched
>> 10D image compares quite favorably to the 4x5, although the
> stitching
>> is very tedious and time consuming.  You would need a 40 MP
> digital
>> camera to get single shot images comparable to the size and
> quality of
>> either the 4x5 or stitched 10D images.
>>
>> http://homepage.mac.com/scho/forweb/index.htm