Olympus-OM
[Top] [All Lists]

Re: [OM] A wasted effort

Subject: Re: [OM] A wasted effort
From: "C.H.Ling" <ch_photo@xxxxxxxxxxxxx>
Date: Tue, 17 Mar 2009 10:47:31 +0800
No one would argue there is degrade in image quality at F22 but I will not 
put all my trust to calculation figures. I didn't see any 4MP (even 8MP) 
digital camera can produce the image I got here at F22, I'm happy to see if 
there is one.

BTW, besides slight lost in resolution there is greater drop in fine 
contrast at F22, use suitable unsharp mask can bring the F22 image very 
close to the F4 one. For instant, I tried 10% R20 + 80% R0.8, it gives great 
improvement without visable artifacts.

C.H.Ling

----- Original Message ----- 
From: "Chuck Norcutt"

> Well, the fact is that 4MP can still make a passable 8x10.  But why have
> a 21MP camera if your happy with 4?  You have to look carefully but
> there are most certainly big differences in the two photos.  For
> example, near the center and at the top of the building is a large
> square red logo with "H", "K" and a stylized "S" shape in the center. A
> little over twice its width and to the right of that logo is what looks
> like a fan in a gray metal housing.  In the f/4 image the louvers in the
> fan housing are quite sharp and distinct.  But in the f/22 image they've
> been nearly blurred out of existence.  And these are straight lines
> which are the easiest things for the eye to see.  In fact the eye
> sometimes sees straight lines where they don't exist by trying to
> connect fragments of detail.  In other words, the detail here has been
> obliterated.  Can I prove it's now a 4MP image?  Nope.  Can you prove
> that it's not?  All I can say is that it has lost fine detail that the
> camera and lens are capable of resolving and did resolve at a wider
> aperture.
>
> Chuck Norcutt
>
>
> Ken Norton wrote:
>>> So at F22 the image only have 4MP resolution, right? But this 4MP image
>>> looks pretty good to me.
>>>
>>
>>
>> Wow, that F22 image is just horrid.  I can plainly see that the lens is
>> diffraction limited at F4.
>>
>> NOT!
>>
>> Good example of how diffraction limits seem to have a different bearing 
>> in
>> the digital world than in the dark ages of film. Now, can anybody show me
>> hard evidence that we really are running into diffraction limits with our
>> new fangled digital cameras?
>>
>> AG

-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz