From: Herb Chong [EMAIL PROTECTED]
Date: 2005/08/26 Fri AM 01:16:58 GMT
To: pentax-discuss@pdml.net
Subject: Re: Re: Wideangle enablement :)
however, the A* lenses with rear filter mounts don't require a filter in the
filter mount at all times.
Herb...
Even more interesting
On Thu, Aug 25, 2005 at 03:25:16PM +0100, Chris Stoddart wrote:
On Thu, 25 Aug 2005, mike wilson wrote:
Empiricism seems to be the only saviour here. Time to get 'em out! 8-)
Yay, that's what we need - some tests! If everyone who's willing and owns
a Mir-47K 20mm f/2.5 can take a picture
On Wed, 24 Aug 2005, Steve Jolly wrote:
If you examine the filters carefully, you can see that they're slightly
concave lenses rather than plain glass. (This is most obvious if you
look at the reflection of a light source in them - you can see two
images, one bigger than the other). I
From: Chris Stoddart [EMAIL PROTECTED]
Date: 2005/08/25 Thu AM 09:15:34 GMT
To: pentax-discuss@pdml.net
Subject: Re: Wideangle enablement :)
On Wed, 24 Aug 2005, Steve Jolly wrote:
If you examine the filters carefully, you can see that they're slightly
concave lenses rather
On Thu, Aug 25, 2005 at 10:15:34AM +0100, Chris Stoddart wrote:
On Wed, 24 Aug 2005, Steve Jolly wrote:
If you examine the filters carefully, you can see that they're slightly
concave lenses rather than plain glass. (This is most obvious if you
look at the reflection of a light source in
Chris Stoddart wrote:
Also I can't
see any concavity/convexity on the filters and they don't seem to alter
the image when you look through them...
It's very very slight. I could only deduce it by looking at the
reflection of a light fitting, as I described. At the very least the
filter
On Thu, 25 Aug 2005, mike wilson wrote:
They don't need to have a curve on them to act as a lens. If a light
ray is hitting them at an angle, it will be deflected by refraction.
http://www.ps.missouri.edu/rickspage/refract/refraction.html
Would make all the difference between a sharp and
On Thu, 25 Aug 2005, Steve Jolly wrote:
It's very very slight. I could only deduce it by looking at the
reflection of a light fitting, as I described. At the very least the
filter has to affect the focussing of the lens slightly, since its
increased optical depth wrt the air it replaces
From: Chris Stoddart [EMAIL PROTECTED]
Date: 2005/08/25 Thu PM 12:15:18 GMT
To: pentax-discuss@pdml.net
Subject: Re: Re: Wideangle enablement :)
On Thu, 25 Aug 2005, mike wilson wrote:
They don't need to have a curve on them to act as a lens. If a light
ray is hitting them
From: Chris Stoddart [EMAIL PROTECTED]
Date: 2005/08/25 Thu PM 12:49:22 GMT
To: pentax-discuss@pdml.net
Subject: Re: Wideangle enablement :)
On Thu, 25 Aug 2005, Steve Jolly wrote:
It's very very slight. I could only deduce it by looking at the
reflection of a light fitting
fra: mike wilson [EMAIL PROTECTED]
From: Chris Stoddart [EMAIL PROTECTED]
On Thu, 25 Aug 2005, Steve Jolly wrote:
It's very very slight. I could only deduce it by looking at the
reflection of a light fitting, as I described. At the very least the
filter has to affect the
Chris Stoddart wrote:
Or maybe it's concave to make sure it *doesn't* have any effect? If a flat
sheet of glass (re Mike Wilson's suggestion) has the effect of changing
the angle of refraction noticeably at higher angles of incidence (and
this *is* a wide angle lens) then it would make sense
On Thu, 25 Aug 2005, mike wilson wrote:
Empiricism seems to be the only saviour here. Time to get 'em out! 8-)
Yay, that's what we need - some tests! If everyone who's willing and owns
a Mir-47K 20mm f/2.5 can take a picture with and without the clear filter
on the back, then scan the two
From: Chris Stoddart [EMAIL PROTECTED]
Date: 2005/08/25 Thu PM 02:25:16 GMT
To: pentax-discuss@pdml.net
Subject: Re: Re: Wideangle enablement :)
On Thu, 25 Aug 2005, mike wilson wrote:
Empiricism seems to be the only saviour here. Time to get 'em out! 8-)
Yay, that's what we
On Aug 25, 2005, at 5:15 AM, Chris Stoddart wrote:
They don't need to have a curve on them to act as a lens. If a light
ray is hitting them at an angle, it will be deflected by refraction.
http://www.ps.missouri.edu/rickspage/refract/refraction.html
Would make all the difference between a
however, the A* lenses with rear filter mounts don't require a filter in the
filter mount at all times.
Herb...
- Original Message -
From: mike wilson [EMAIL PROTECTED]
To: pentax-discuss@pdml.net
Sent: Thursday, August 25, 2005 10:34 AM
Subject: Re: Re: Wideangle enablement
At last, russian post has done it's deed... :)
My long wanted MIR-47 2.5/20 is here, at last.
For those not in the know, here it is:
http://rugift.com/photocameras/mir_47_k_lens.htm
Lately, there was a thread here, that speculated problems with the rear
lens assortment with this lens. I just
Vid Strpic wrote:
My long wanted MIR-47 2.5/20 is here, at last.
Lately, there was a thread here, that speculated problems with the rear
lens assortment with this lens. I just put it on my ME Super, and did a
few shots (I will do more, ofcourse). No such problems, this lens is a
On Wed, Aug 24, 2005 at 01:03:48PM +0100, Steve Jolly wrote:
Vid Strpic wrote:
My long wanted MIR-47 2.5/20 is here, at last.
Lately, there was a thread here, that speculated problems with the rear
lens assortment with this lens. I just put it on my ME Super, and did a
few shots (I will do
Vid Strpic wrote:
Correction. With rear filter mounted, it DOES interfere with the mirror
;)
Without the filter the situation is normal, and it seems that unlike
Zenitar, this lens does not NEED to have filter mounted to focus
properly. But, we'll see when I develop this roll ;)
If you
On Wed, Aug 24, 2005 at 01:22:21PM +0100, Steve Jolly wrote:
Vid Strpic wrote:
Correction. With rear filter mounted, it DOES interfere with the mirror
;)
Without the filter the situation is normal, and it seems that unlike
Zenitar, this lens does not NEED to have filter mounted to focus
21 matches
Mail list logo
