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 Photography
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

"1:" on lens label -- what does it mean?



 
 
Thread Tools Display Modes
  #1  
Old October 30th 05, 10:52 PM
none
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

On the front of my P/S lens, there is a label that says:
5.8-32mm 1:2.6-5.5

And on the front of my film SLR lens, the label says:
35-80mm 1:4-5.6

My question is, what does the "1:" in front of the aperture mean?

Thanks,
-Mike
  #2  
Old October 30th 05, 11:04 PM
Patrick Cleburne
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

"none" wrote in message
news:Hgb9f.5029$UW5.886@trndny09...
On the front of my P/S lens, there is a label that says:
5.8-32mm 1:2.6-5.5

And on the front of my film SLR lens, the label says:
35-80mm 1:4-5.6

My question is, what does the "1:" in front of the aperture mean?

Thanks,
-Mike


It's a carry over from expressing the f stop or how wide the lens can open
as a ratio. On most contemporary zoom lenses, the maxim aperture or f stop
gets smaller as the lens zooms out. In your case, at 35mm focal length, the
maximum f stop is 4 but as you zoom out to 80mm, the f stop is smaller
(higher number, huh) meaning that less light passes through the lens. Other
things being equal, you need brighter light to shoot when you have the lens
zoomed out to telephoto. You need more light to shoot with a "slow" lens
tha thas a max aperture (opening) of f/4 or f/5.6 than you woule for one
with f/1.8 or 2.8.

Pick up a beginner's book on photography-- or find a website-- that will
explain it in more detail if you're interested.

Pat


  #3  
Old October 30th 05, 11:13 PM
Stephen M. Dunn
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

In article Hgb9f.5029$UW5.886@trndny09 none writes:
$On the front of my P/S lens, there is a label that says:
$5.8-32mm 1:2.6-5.5
$
$And on the front of my film SLR lens, the label says:
$35-80mm 1:4-5.6
$
$My question is, what does the "1:" in front of the aperture mean?

It's just a different way of writing f/, expressing it as a ratio
rather than by division.

f/x means the size of the aperture is the focal length divided
by x; in optics, the letter f is used to denote focal length (and
on some lenses, you'll actually see the focal length shown in the
form "f=50mm").

1:x means that the ratio of the aperture to the focal length is
1:x.
--
Stephen M. Dunn
---------------- http://www.stevedunn.ca/ ----------------

------------------------------------------------------------------
Say hi to my cat -- http://www.stevedunn.ca/photos/toby/
  #4  
Old October 31st 05, 01:43 PM
Neil Ellwood
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

On Sun, 30 Oct 2005 21:52:39 +0000, none wrote:

On the front of my P/S lens, there is a label that says:
5.8-32mm 1:2.6-5.5

And on the front of my film SLR lens, the label says:
35-80mm 1:4-5.6

My question is, what does the "1:" in front of the aperture mean?

Thanks,
-Mike

The 1 is part of the ratio of the lens aoerture, the commonly quoted
'stops' are just the second half of the ratio.
f1:2.0 just means that the aperture diameter is half the focal length of
the lens.
HTH

--
Neil
Delete delete to reply by email
  #5  
Old November 1st 05, 01:21 PM
kctan
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

The "1" refer to focal length.
when you set to 35mm FL means 35/4 and this is the diameter of the aperture
= 8.75mm
when you set to 80mm FL means 80/4 and this is the diameter of the aperture
= 14.28mm
when the aperture is not a circle, take the area for equilibrium.

"Patrick Cleburne" mgcleburne@rebnet wrote in message
...
"none" wrote in message
news:Hgb9f.5029$UW5.886@trndny09...
On the front of my P/S lens, there is a label that says:
5.8-32mm 1:2.6-5.5

And on the front of my film SLR lens, the label says:
35-80mm 1:4-5.6

My question is, what does the "1:" in front of the aperture mean?

Thanks,
-Mike


It's a carry over from expressing the f stop or how wide the lens can open
as a ratio. On most contemporary zoom lenses, the maxim aperture or f stop
gets smaller as the lens zooms out. In your case, at 35mm focal length,
the maximum f stop is 4 but as you zoom out to 80mm, the f stop is smaller
(higher number, huh) meaning that less light passes through the lens.
Other things being equal, you need brighter light to shoot when you have
the lens zoomed out to telephoto. You need more light to shoot with a
"slow" lens tha thas a max aperture (opening) of f/4 or f/5.6 than you
woule for one with f/1.8 or 2.8.

Pick up a beginner's book on photography-- or find a website-- that will
explain it in more detail if you're interested.

Pat



  #6  
Old November 1st 05, 01:24 PM
kctan
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

Sorry, should be 80/5.6 = 14.28mm

"kctan" wrote in message
...
The "1" refer to focal length.
when you set to 35mm FL means 35/4 and this is the diameter of the
aperture = 8.75mm
when you set to 80mm FL means 80/5.6 and this is the diameter of the
aperture = 14.28mm
when the aperture is not a circle, take the area for equilibrium.

"Patrick Cleburne" mgcleburne@rebnet wrote in message
...
"none" wrote in message
news:Hgb9f.5029$UW5.886@trndny09...
On the front of my P/S lens, there is a label that says:
5.8-32mm 1:2.6-5.5

And on the front of my film SLR lens, the label says:
35-80mm 1:4-5.6

My question is, what does the "1:" in front of the aperture mean?

Thanks,
-Mike


It's a carry over from expressing the f stop or how wide the lens can
open as a ratio. On most contemporary zoom lenses, the maxim aperture or
f stop gets smaller as the lens zooms out. In your case, at 35mm focal
length, the maximum f stop is 4 but as you zoom out to 80mm, the f stop
is smaller (higher number, huh) meaning that less light passes through
the lens. Other things being equal, you need brighter light to shoot when
you have the lens zoomed out to telephoto. You need more light to shoot
with a "slow" lens tha thas a max aperture (opening) of f/4 or f/5.6 than
you woule for one with f/1.8 or 2.8.

Pick up a beginner's book on photography-- or find a website-- that will
explain it in more detail if you're interested.

Pat





  #7  
Old November 1st 05, 05:53 PM
Lorem Ipsum
external usenet poster
 
Posts: n/a
Default "1:" on lens label -- what does it mean?

It is the depreciation schedule for the camera.
1:4.5 is the rate of depreciation in % for each day you own it.


 




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 Off
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: Schneider Large-Format Lens TRADE!!! Bill Gillooly General Equipment For Sale 2 February 20th 05 07:43 AM
Digital vs Film - just give in! [email protected] Medium Format Photography Equipment 159 November 15th 04 05:56 PM
perspective w/ 35mm lenses? PrincePete01 Digital Photography 373 August 10th 04 02:21 PM
The opposite of a close-up lens? Ralf R. Radermacher Medium Format Photography Equipment 44 April 14th 04 03:55 PM
FS: Nikon F4, Nikkor Lens and accessories. FocaIPoint 35mm Equipment for Sale 0 August 24th 03 07:23 PM


All times are GMT +1. The time now is 08:58 AM.


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.