Yes, it must be frustrating - but you can prevent the focal length change by
taping or gluing the focusing ring so that it will not move.
All the best!
Raimo K
Personal photography homepage at:
http://www.uusikaupunki.fi/~raikorho
----- Original Message -----
From: "Tim Øsleby" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, October 29, 2005 1:54 AM
Subject: RE: My new Macro - a lemon.
<snip>
And there is this with the focal length changing. That too is visible in
the
test shots. It's just a couple of degrees change in angle of view, but
this
to makes me sceptic.
<snip>
Tim
Mostly harmless (just plain Norwegian)
Never underestimate the power of stupidity in large crowds
(Very freely after Arthur C. Clarke, or some other clever guy)
-----Original Message-----
From: Raimo K [mailto:[EMAIL PROTECTED]
Sent: 29. oktober 2005 00:33
To: [email protected]
Subject: Re: My new Macro - a lemon.
OK - there was a speck in one image but not on the others. Maybe it is a
subject failure?
All the best!
Raimo K
Personal photography homepage at:
http://www.uusikaupunki.fi/~raikorho
----- Original Message -----
From: "Tim Øsleby" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, October 29, 2005 1:19 AM
Subject: RE: My new Macro - a lemon.
> First test shots. Done in a hurry. Roughly converted
> http://www.flickr.com/photos/fototim/sets/1234555/
>
>
> Tim
> Mostly harmless (just plain Norwegian)
>
> Never underestimate the power of stupidity in large crowds
> (Very freely after Arthur C. Clarke, or some other clever guy)
>
>> -----Original Message-----
>> From: William Robb [mailto:[EMAIL PROTECTED]
>> Sent: 28. oktober 2005 23:33
>> To: [email protected]
>> Subject: Re: My new Macro - a lemon.
>>
>>
>> ----- Original Message -----
>> From: "Tim Øsleby"
>> Subject: RE: My new Macro - a lemon.
>>
>>
>> > As I say in a reply to WB:
>> > I haven't noticed change of focal length when focusing. It is when
>> > changing
>> > aperture. Is that normal too?
>> >
>> > My observation on the dust is simply based on what I see in my raw
>> > converter. I have no idea of the magnification ratio. On screen the
>> image
>> > is
>> > about 8 x 5 inches. The test shot was shot at about 20cm. It is
visible
>> > from
>> > f5,6, really disturbing from f8, horrifying at f16. I assume that it
>> fades
>> > out when opening aperture proves that it isn't sensor dust.
>>
>> I think you might consider showing us a picture of the glass, and dust
>> blob
>> in question.
>> And perhaps a few web images of how the dust spec is afecting things.
>>
>> Focal length should not change with aperture.
>>
>> William Robb
>>
>>
>
>
>
>
