[filmscanners] Re: Canon IDs vs Pentax 67II

["Arthur Entlich" <artistic-1@shaw.ca>]

Or, maybe all those problems you're claiming may have occurred with the
Pentax with film actually occurred with the Canon digital, and the Canon
digital is even ia lot better than the test shows? ;-)

I'm kidding... I am also surprised by the results.  The drum scan does
show a lot more resolution than his Imacon scan.  And the close up shows
that there is no detail on the windows from the digital while the film
has a good amount.

Art


focus@adnc.com wrote:

> I'm not sure how I missed that. Guess I win the "Arrogant Moron of the Week" 
>award!
>
> I do, however stand behind the part about the Pentax having to resolve less 
>than 30 lp/mm to get
> outresolved by the Canon (and um, it should be 30 not 29 as in the original 
>post--I should have
> divided 2700 by 24, not 25.2, but it's not really significant). Something's 
>gotta be wrong.
> Maybe his film plane and ground glass are at different distances, maybe the 
>huge focal-plane
> shutter is contributing shake, maybe he fired with the release on the body 
>instead of using a
> cable, maybe he didn't let the vibration from winding on settle before he 
>fired, maybe his lens
> has a manufacturing problem, maybe a dozen other things. I just refuse to 
>believe a P67 can only
> resolve 30 lp/mm!
>
> Arthur Entlich wrote:
>
>
>> From the website:
>>
>>"Both cameras were tripod mounted beside each other. The Canon was
>>autofocused on the buildings at infinity and I focused the Pentax
>>manually. Mirror lock-up was used on the Pentax, but not on the Canon.
>>Aperture was set at f/8 on both cameras, close to optimum. Shutter speed
>>was 1/90th sec on the Pentax and 1/250th sec on the Canon (due to ISO 40
>>with Velvia and ISO 100 with the 1Ds)."
>>
>>Just to keep things accurate.
>>
>>Art
>>
>>focus@adnc.com wrote:
>>
>>
>>>This is B.S. -- if I set out to make MF look bad, a Pentax 67 with a long 
>lens at a
>>>middling shutter speed without the mirror locked up is EXACTLY what I'd 
>choose.
>>>
>>>How much is Canon paying this guy?
>>>The Canon can at the very best resolve a little over 50 lp/mm (2700/25.2=107 
>pixels/mm,
>>>107/2=53.5 lp/mm.)
>>>
>>>Since the Pentax' capture area is 1.86 to 2.25 times larger (depending on 
>the dimension you
>>>choose) it would need to resolving no more than 29 lp/mm (53.5/1.86) to be 
>outresolved by
>>>the Canon. Does anyone really believe that the Pentax, properly used, can 
>only resolve 29
>>>lp/mm?
>>>
>>>The Pentax 67 is notorious for shaking like a junkie on the first day of 
>rehab, and this
>>>was shot at 1/90th, with no mention of using mirror lock-up. A tripod does 
>not "cure"
>>>mirror slap; it reduces it, but it does NOT eliminate it. And the long lens 
>chosen for this
>>>test makes it much more of a factor. Show me a test where the Pentax had a 
>100mm lens at
>>>5.6 on Provia 100 (which should give you at least a 250th in the same 
>conditions) and the
>>>mirror locked up, and I'll bet anything the Pentax wins by a lot.
>>>
>>>And why screw around printing it out? All that does is introduce another 
>irrelevant factor,
>>>one which almost certainly downsamples the Pentax image. Just show us 
>digital file to
>>>digital file, with the smaller file upsampled to match. This was about "is 
>digital better
>>>than 6 x 7" not "is digital better than 6 x 7 given my particular printing 
>workflow".
>>>


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