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[OM] Re: Anyone Have an ED12-60/2.8-4?

Subject: [OM] Re: Anyone Have an ED12-60/2.8-4?
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Sat, 12 Jan 2008 08:54:10 -0500
Probably OK to control costs on kit lenses but I don't think I'd like to 
see that more generally used on higher end lenses.  The only way to 
correct the vignetting is to apply more amplificiation.  If I was 
shooting at ISO 1600 but the lens is losing a stop at the edges the 
amplification to correct it means the edges are shot at the equivalent 
of 3200.  The end result could significantly limit the amount of control 
available for any other post processing required.

Chuck Norcutt

Moose wrote:
> Wayne Harridge wrote:
>>> All Zuiko lenses contain a built-in CPU that actively communicates with the 
>>> camera to correct any potential shading and distortion problems. And it is 
>>> user upgradeable. Something impossible with film lenses." 
>> ..and something that is unnecessary with well designed lenses !
>>   
> I'm not sure I completely agree.With the standalone lens of the old 
> days, sure. There is no way of know what kind of body a press/view 
> camera lens is going to be mounted on, or an Adaptall. The lenses were 
> entirely mechanical and the optical design had to stand on its own. 
> given that the bodies were largely mechanical and had no lecroinc means 
> of communication with the lenses, this was true of all MF lenses.
> 
> In a contemporary system like 4/3, with programmability of both body and 
> lens and a defined electronic interface for communication between them, 
> the number of variables available to the designer become greater.
> 
> The designer might, for example be able to more completely control CA, 
> or perhaps linear distortion, in a WA lens because vignetting could be 
> allowed to get worse than would be acceptable in a stand alone lens, 
> knowing that vignetting may be corrected electronically in the camera 
> body without any artifacts. Vignetting is a natural first choice 
> trade-off, as it only involves adjusting brightness of pixels, without 
> any of the movement and interpolation of pixels required by distortion 
> correction.
> 
> If a combined approach of optical design and electronic "correction" 
> results in equal performance with less cost in size, weight and price, 
> I'd call that progress. Based on their price, size, weight and reported 
> performance, it appears that this approach may be paying off with the 
> latest kit lenses offered with the E-410/510. User reports and reviews 
> seem to indicate that they are better performers than anyone else's kit 
> lenses, yet they are smaller and cheaper than, and reportedly 
> outperform, the previous kit set.
> 
> Likewise if combined design results in a lens/body combination with 
> superior performance to a similar, stand alone, lens design, I'll call 
> that progress, too. I don't know if that has happened yet, but I'm sure 
> it will. Whether by Oly or not, who knows?
> 
> Moose
> 
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