Archived posting to the Leica Users Group, 2012/07/10

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Subject: [Leica] Nikon forum advice (OT!)
From: john at chiaroscuro.co.nz (John McMaster)
Date: Tue, 10 Jul 2012 19:55:50 +1200
References: <29727A43-B108-4352-8AB9-0CA04570CD54@gmail.com> <CC21445D.20E2D%mark@rabinergroup.com>

Sorry not fully explained, it is the size of circle of confusion in relation
to sensor pixel size, so for 30-micron and 5-micron circle of confusion
where high density sensors (NEX-7, D800 etc) have sensor pixels smaller than
5-micron.

john

-----Original Message-----

Very possible at closer distances ;-) With the newer higher density sensors
it is effectively reduced even more.....

DoF for 15mm @ f5.6 and focus on 3m:

30-micron pixel sensor  0.96m - infinity

5-micron pixel sensor   2.22m - 4.65m

36MP on 24x36 is changing the whole ballpark

At f2.8 and 30cm focus only 2cm DoF on 5-micron sensors!

john

-----Original Message-----


A little hard though to get anything out of focus with a 15mm lens on a
24x36 image area. So its hard to call it a bokeh issue. Its just asphs are
going to help make it a better lens issue.

- - from my iRabs.
Mark Rabiner
http://gallery.leica-users.org/v/lugalrabs/


> 
> And the 15 Zeiss was the tipping $ point that was not made by Cosina, 
> putting it out of my reach. I do have the 15 VC but virtually never use
it.
> 
> I regret not doing a PAW, and admire those doing a PAW or PESO. The 
> pressure of doing a PAW made me think photographic thoughts every day. 
> And, pathologically, digital seem to steal some of the magic. Instead 
> of scanning
> 36 frames, I was editing 720 frames.
> 
> Sent from my iPad
> 
> Jeffery L. Smith
> New Orleans, Louisiana
> USA
> 
> On Jul 9, 2012, at 22:24, John McMaster <john at mcmaster.co.nz> wrote:
> 
>> I think the 15mm is the only asph in the ZM range. I suspect that the 
>> Zeiss SLR range will start to get asph lenses as CA is a big issue on 
>> the D800(E) with them.
>> 
>> john
>> ________________________________________
>> 
>> 
>> I'm willing to throw Zeiss into that as well. I'm not sure that Zeiss 
>> uses as much asph as Leica, or if they just don't mention it in the lens
name.
>> 
>> It is probably a flaw in my standards that I don't care so much about 
>> corner sharpness. If the corner is that important, I should have put 
>> it in the middle instead of the corner.
>> 
>> Other than my Russian lenses, virtually everything I own is good 
>> enough for me (= better than me). I really don't like anything about 
>> zoom lenses and rarely use them on my dSLR cameras.
>> 
>> Sent from my iPad
>> 
>> Jeffery L. Smith
>> New Orleans, Louisiana
>> USA
>> 
>> On Jul 9, 2012, at 21:49, John McMaster <john at mcmaster.co.nz> wrote:
>> 
>>> Ah, I was talking Leica asph ;-)
>>> 
>>> john
>>> ________________________________________
>>> 
>>> 
>>> The Voigtlander 50/1.5 Nokton was perhaps the first really sharp, 
>>> afforable, asph lens that people hated for its bokeh. The trend in 
>>> thinking seemed to be that reducing aberrations with asph elements 
>>> benefitted everything except bokeh.
>>> 
>>> I think every lens needs to be assessed on its own merit. I don't 
>>> have any bad Leica lenses, though the old 50/3.5 Elmar performs like a
Russian copy.
>>> Wait, maybe it is....
>>> 
>>> The 50/2.5 Hexanon is better.
>>> 
>>> Sent from my iPad
>>> 
>>> Jeffery L. Smith
>>> New Orleans, Louisiana
>>> USA
>>> 
>>> On Jul 9, 2012, at 20:56, John McMaster <john at mcmaster.co.nz> wrote:
>>> 
>>>> I think that is a widely held misconception....
>>>> 
>>>> john
>>>> ________________________________________
>>>> 
>>>> 
>>>> By the way, George, you had some incredibly creamy-bokeh shots 
>>>> posted the other day, and one of them was with an aspherical Leica 
>>>> lens(!). It blew away my bias that aspherical = bad bokeh.
>>>> 




In reply to: Message from jsmith342 at gmail.com (Jeffery Smith) ([Leica] Nikon forum advice (OT!))
Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] Nikon forum advice (OT!))