A Photography forum. PhotoBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PhotoBanter.com forum » Digital Photography » Digital SLR Cameras
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

fast glass?



 
 
Thread Tools Display Modes
  #51  
Old January 11th 06, 01:40 AM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

"Skip M" wrote:

That, in no way, contradicts what I said. The Leica f2.8 will likely be
sharper at 5.6 than at 2.8, and will certainly be sharper than a 5.6 lens
will be at 5.6.



Sorry, Skip, but you are wrong. The Leica 24mm f/2.8 ASPH is sharper
in the centre at f/2.8 than at any other aperture. It is marginally
sharper at the edges at f/4 than at f/2.8, however sharpness
diminishes at smaller apertures as the lens is effectively diffraction
limited. The edges are sharper at f/2.8 than f/5.6, and of course
sharpest at f/4. Sorry to repeat myself but I wish to emphasise the
point.

Similar properties are to be found in other modern Leica lenses. It
isn't just this one plus the 50mm f/1.0 Noctilux, you will find
similar optical performance in lenses such as the Leica Elmarit-M 21mm
f/2.8 ASPH, the Summilux-M 35mm f/1.4 ASPH, the Summicron-M 35mm f/2.0
ASPH, both 75mm M lenses, both 90mm M lenses and the superlative
135mm.

Slightly older Leica M lenses do perform at their best stopped down,
but you typically only need to stop down by 2 stops to get the best
performance, whereas most lenses for 35mm SLR cameras need to be
stopped down by 4 stops. For example, a 4th version Leica Summicron-M
35mm f/2.0 is sharpest at f/4, whereas an AF Nikkor 35mm f/2D peaks at
f/8 to f/11.

These are significant differences, and coupled with the excellent
drawing (almost zero distortion), outstanding level of correction of
aberrations and extreme consistency between samples, they go a long
way to explaining the high price of Leica glass.


  #52  
Old January 11th 06, 03:00 AM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

"Tony Polson" wrote in message
...
"Skip M" wrote:

That, in no way, contradicts what I said. The Leica f2.8 will likely be
sharper at 5.6 than at 2.8, and will certainly be sharper than a 5.6 lens
will be at 5.6.



Sorry, Skip, but you are wrong. The Leica 24mm f/2.8 ASPH is sharper
in the centre at f/2.8 than at any other aperture. It is marginally
sharper at the edges at f/4 than at f/2.8, however sharpness
diminishes at smaller apertures as the lens is effectively diffraction
limited. The edges are sharper at f/2.8 than f/5.6, and of course
sharpest at f/4. Sorry to repeat myself but I wish to emphasise the
point.

Similar properties are to be found in other modern Leica lenses. It
isn't just this one plus the 50mm f/1.0 Noctilux, you will find
similar optical performance in lenses such as the Leica Elmarit-M 21mm
f/2.8 ASPH, the Summilux-M 35mm f/1.4 ASPH, the Summicron-M 35mm f/2.0
ASPH, both 75mm M lenses, both 90mm M lenses and the superlative
135mm.

Slightly older Leica M lenses do perform at their best stopped down,
but you typically only need to stop down by 2 stops to get the best
performance, whereas most lenses for 35mm SLR cameras need to be
stopped down by 4 stops. For example, a 4th version Leica Summicron-M
35mm f/2.0 is sharpest at f/4, whereas an AF Nikkor 35mm f/2D peaks at
f/8 to f/11.

These are significant differences, and coupled with the excellent
drawing (almost zero distortion), outstanding level of correction of
aberrations and extreme consistency between samples, they go a long
way to explaining the high price of Leica glass.


Hmm, interesting. I guess I need to backpedal a bit...

--
Skip Middleton
http://www.shadowcatcherimagery.com


  #53  
Old January 11th 06, 05:53 AM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?



Tony Polson wrote:

"Skip M" wrote:

That, in no way, contradicts what I said. The Leica f2.8 will likely be
sharper at 5.6 than at 2.8, and will certainly be sharper than a 5.6 lens
will be at 5.6.


Sorry, Skip, but you are wrong. The Leica 24mm f/2.8 ASPH is sharper
in the centre at f/2.8 than at any other aperture. It is marginally
sharper at the edges at f/4 than at f/2.8, however sharpness
diminishes at smaller apertures as the lens is effectively diffraction
limited. The edges are sharper at f/2.8 than f/5.6, and of course
sharpest at f/4. Sorry to repeat myself but I wish to emphasise the
point.

Similar properties are to be found in other modern Leica lenses. It
isn't just this one plus the 50mm f/1.0 Noctilux, you will find
similar optical performance in lenses such as the Leica Elmarit-M 21mm
f/2.8 ASPH, the Summilux-M 35mm f/1.4 ASPH, the Summicron-M 35mm f/2.0
ASPH, both 75mm M lenses, both 90mm M lenses and the superlative
135mm.

Slightly older Leica M lenses do perform at their best stopped down,
but you typically only need to stop down by 2 stops to get the best
performance, whereas most lenses for 35mm SLR cameras need to be
stopped down by 4 stops. For example, a 4th version Leica Summicron-M
35mm f/2.0 is sharpest at f/4, whereas an AF Nikkor 35mm f/2D peaks at
f/8 to f/11.

These are significant differences, and coupled with the excellent
drawing (almost zero distortion), outstanding level of correction of
aberrations and extreme consistency between samples, they go a long
way to explaining the high price of Leica glass.




Tony, there is a link that documents Leica lens manufacturing which I
have forgotten. The piece is quite lengthy but extremely informative.
It's a great read. Would you have an idea what I may be referring to?

Thanks,

JT
  #54  
Old January 11th 06, 04:35 PM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

k-man wrote:
perhaps people don't realise that you're just not going to get the same
image quality out of wide open lens and are mistaking 'softness' for focus
issues. Just a thought.



Untrue. I've seen f/1.4 lenses shoot better at f/1.8 than f/1.8 lenses
of equal focal length (better meaning better bokeh, brightness,
sharpness.etc.). I'm not saying that's been the case for all 1.4 vs.
1.8 lenses. But in those cases, you just might want the faster lens
just because it's a better lens.


That's the thing... there's such a wide range in quality (and prices) of
lenses that you just can't make those kinds of generalizations. Somehow
I expect an 18mm, f/1.4 Canon L-series lens (dunno if it exists, just
tossing out some numbers for illustration) would be a LOT sharper than
my 300D's 18-55mm f/4 "kit" lens, even wide open.


---
avast! Antivirus: Outbound message clean.
Virus Database (VPS): 0602-1, 01/09/2006
Tested on: 1/11/2006 7:34:47 AM
avast! - copyright (c) 1988-2005 ALWIL Software.
http://www.avast.com



  #55  
Old January 11th 06, 07:42 PM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

Jeremy Nixon writes:

David Dyer-Bennet wrote:

Indoors, it's even worse. I shoot my 58mm f1.2 NOCT at f1.2 fairly
often.


That lens is actually designed to be at optimum wide open.


It's a great portrait lens, especially for available light candid
portraits, on a 1.5x DSLR. Lets me blur the background if needed,
too.

Don't suppose you want to sell it? I've been looking for one of those
at a non-insane price for quite some time now; very difficult to get hold
of. I wish they hadn't discontinued them -- they were $1500 new, and I'd
be willing to pay that for a like-new one, but people seem to hold out
until someone comes along willing to pay much more. (I've watched people
list and re-list them on eBay for weeks and weeks until someone finally
steps up and pays $2k or whatever for a worn-out one with dust inside.)


I lucked into mine for $700 used, back somewhere in the early 90s I
think, at the National Camera Exchange "tent sale" at their store out
on I394 here in Minneapolis. It was kind of a stretch, but that
seemed like an awfully good price. (Then, B&H was listing them new
for $1589 as I remember it; they may already have been out of
production.)
--
David Dyer-Bennet, , http://www.dd-b.net/dd-b/
RKBA: http://noguns-nomoney.com/ http://www.dd-b.net/carry/
Pics: http://dd-b.lighthunters.net/ http://www.dd-b.net/dd-b/SnapshotAlbum/
Dragaera/Steven Brust: http://dragaera.info/
  #56  
Old January 11th 06, 08:41 PM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

"Skip M" wrote:

"Tony Polson" wrote in message

snip
These are significant differences, and coupled with the excellent
drawing (almost zero distortion), outstanding level of correction of
aberrations and extreme consistency between samples, they go a long
way to explaining the high price of Leica glass.


Hmm, interesting. I guess I need to backpedal a bit...



Only a little bit, Skip. What you said is true of over 99% of lenses.

;-)

  #57  
Old January 12th 06, 06:29 AM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?

"Tony Polson" wrote in message
...
"Skip M" wrote:

"Tony Polson" wrote in message

snip
These are significant differences, and coupled with the excellent
drawing (almost zero distortion), outstanding level of correction of
aberrations and extreme consistency between samples, they go a long
way to explaining the high price of Leica glass.


Hmm, interesting. I guess I need to backpedal a bit...



Only a little bit, Skip. What you said is true of over 99% of lenses.

;-)

True, I did say I can _think_ of no exceptions... ;-)

--
Skip Middleton
http://www.shadowcatcherimagery.com


  #58  
Old January 12th 06, 09:57 AM posted to rec.photo.digital,rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default fast glass?


everyone seems to want 'fast glass' - f/2.8, 1.7, 1.4, etc, but I'm left
wondering 'why' As most people know, lenses are not at their sharpest

wide
open - usually requiring f/7 - 9 (ish) before they attain their maximum
potential.

So why the fuss about 'fast' lenses?, and why pay the huge premiums to own
them? Most of my own lenses are 2.8, with one at 1.7, and one at 1.4 -

yet
I invariably have to stop down in order to get a nicely sharp image, which
sort of defeats the object of the 'fast glass', doesn't it?

I mean, why pay three times the price for a 'fast' lens, when you only end
up stopping it down? I've got a theory that it's the mania for bright

lenses
that's behind a lot of the 'focus fuss' that clogs up the various forums -
perhaps people don't realise that you're just not going to get the same
image quality out of wide open lens and are mistaking 'softness' for focus
issues. Just a thought.


for the most part, you tend to get what you pay for in quality. There are
exceptions of course.

The advantages for having fast glass means that you have more options and
choices. While its true that lenses are typically sharper a stop or two
down, that suggests that my f/2.8 is great at 4 or 5.6 while your 5.6 might
be ok at 8 or you might not even get a contrasty sharp image at 11. Along
with faster exposure, you should get better contrast and resolution, less
flair. Should, sometimes not.

Keep in mind that most of the time the best lighting is found at minimum
levels, twilight, open shade, window light. I find myself shooting at wide
or a stop down, with a 1/15th second or slower quite often. Shooting at
f/4 or 5.6 with a long shutter speed lets me shoot a wedding party on an
altar and getting a nicely lit subject, and a lot of detail out of the
background as the ambient levels build up to one stop under the flash
exposure.

This reply is echoed to the z-prophoto mailing list at yahoogroups.com


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Making Stained Glass at home, help Frank in UK Digital Photography 1 February 8th 05 01:58 PM
Making Stained Glass at home, help starlia 35mm Photo Equipment 0 February 8th 05 01:58 PM
Making Stained Glass at home, help Frank in UK 35mm Photo Equipment 0 February 8th 05 01:04 PM
Heat absorbing glass or one-size-fits all glass carrier for 23CII negative popping problem Phil Glaser In The Darkroom 2 June 1st 04 01:47 PM
Filter glass for Janpol enlarging lens? Donald Qualls In The Darkroom 7 May 29th 04 11:32 PM


All times are GMT +1. The time now is 02:27 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 PhotoBanter.com.
The comments are property of their posters.