From: David J. Littleboy on

"Paul Furman" <paul-@-edgehill.net> wrote:
> stephe_k(a)yahoo.com wrote:
>> MikeWhy wrote:
>>> "Alfred Molon" <alfred_molon(a)yahoo.com> wrote in message
>>> news:MPG.2602e994c867cf0598c25c(a)news.supernews.com...
>>>> In article <hn93o5$v2c$2(a)news.albasani.net>, stephe_k(a)yahoo.com says...
>>>>> B: Is the MF glass resolving enough to do anything if it does
>>>>> resolve as
>>>>> highly. i.e. are you actually gaining anything.
>>>>
>>>> You mean MF glass is unable to resolve 40MP?
>>>
>>> 6 micron pixel pitch is 167 lines/mm.
>>
>> Which very few if any MF lenses can resolve.
>
> If you want to get the most out of a lens' resolution, 3 pixels per detail
> is pretty good.

Yes. Stephe is simply dead wrong here. The 5D2 (which is very close in pixel
pitch to the MF camera under discussion) is 156 pixels per mm. That's 78
lp/mm, which most decent lenses, even MF ones, will resolve nicely.

Here are two Mamiya 645 lenses doing just fine on the 5D2.

55/2.8 at f/8: http://www.pbase.com/davidjl/image/122673675/original

80/2.8 at f/8: http://www.pbase.com/davidjl/image/122673677/original

--
David J. Littleboy
Tokyo, Japan


From: Bruce on
On Fri, 12 Mar 2010 08:37:02 +0100, Alfred Molon
<alfred_molon(a)yahoo.com> wrote:

>In article <hncj41$r2f$2(a)news.albasani.net>, stephe_k(a)yahoo.com says...
>
>> Yet most MF glass doesn't resolve as high as good 35MM glass. MF glass
>> might easily resolve 40MP but probably not on this size sensor..
>
>"Resolve" does not mean much. You probably mean that the MTF will be
>lower. Perhaps there is a way to create new MF lenses with higher
>resolution.


That's probably exactly what lies behind Pentax's new 55mm standard
lens for this camera.

It is almost certain to be a stellar performer because it needs to be.



From: Chris Malcolm on
In rec.photo.digital Paul Furman <paul-@-edgehill.net> wrote:
> stephe_k(a)yahoo.com wrote:
>> MikeWhy wrote:
>>> "Alfred Molon" <alfred_molon(a)yahoo.com> wrote in message
>>> news:MPG.2602e994c867cf0598c25c(a)news.supernews.com...
>>>> In article <hn93o5$v2c$2(a)news.albasani.net>, stephe_k(a)yahoo.com says...
>>>>> B: Is the MF glass resolving enough to do anything if it does
>>>>> resolve as
>>>>> highly. i.e. are you actually gaining anything.
>>>>
>>>> You mean MF glass is unable to resolve 40MP?
>>>
>>> 6 micron pixel pitch is 167 lines/mm.
>>
>> Which very few if any MF lenses can resolve.

> If you want to get the most out of a lens' resolution, 3 pixels per
> detail is pretty good.

Every lens I've got, including the 18-250 zoom, can do that in its
central area under optimum conditions of light, contrast, and
aperture. The difference is that the best can do it in a wider range
of conditions, apertures, and image area.

--
Chris Malcolm
From: David J. Littleboy on

"Bruce" <docnews2011(a)gmail.com> wrote:
> On Fri, 12 Mar 2010 08:37:02 +0100, Alfred Molon
> <alfred_molon(a)yahoo.com> wrote:
>
>>In article <hncj41$r2f$2(a)news.albasani.net>, stephe_k(a)yahoo.com says...
>>
>>> Yet most MF glass doesn't resolve as high as good 35MM glass. MF glass
>>> might easily resolve 40MP but probably not on this size sensor..
>>
>>"Resolve" does not mean much. You probably mean that the MTF will be
>>lower. Perhaps there is a way to create new MF lenses with higher
>>resolution.
>
>
> That's probably exactly what lies behind Pentax's new 55mm standard
> lens for this camera.
>
> It is almost certain to be a stellar performer because it needs to be.

The general opinion over here is that Pentax 645 glass is sharper than
Mamiya 645 glass, and as I demonstrate in my other note, Mamiya 645 glass is
more than adequate for this density of a sensor.

So I don't have a clue as to what they'd come out with a new 55mm lens.
Maybe gunching up performance wide open? Ah, I see. Pentax lenses are also
known for their horrible bokeh, and this one has a rounded diaphragm.

--
David J. Littleboy
Tokyo, Japan


From: Chris Malcolm on
In rec.photo.digital Alfred Molon <alfred_molon(a)yahoo.com> wrote:
> In article <hncj41$r2f$2(a)news.albasani.net>, stephe_k(a)yahoo.com says...

>> Yet most MF glass doesn't resolve as high as good 35MM glass. MF glass
>> might easily resolve 40MP but probably not on this size sensor..

> "Resolve" does not mean much. You probably mean that the MTF will be
> lower. Perhaps there is a way to create new MF lenses with higher
> resolution.

Of coure there is. The equivalent of such lenses have been being made
for specialised scientific purposes for some time. But nobody will
bother making a lens which is too good for its purpose.

--
Chris Malcolm