| Author | Thread |
|
|
06/10/2004 09:09:32 PM · #1 |
I have a couple of questions of things that have niggled at the back of mind for a while, and I've never found an answer. Hopefully someone can enlighten me.
1) Why do compact digicams rarely have lenses that stop down more than F/8? Surely it's not hard to increase the amount the aperture closes?
2) When I was younger, I remember I had a point and shoot film camera, cheap and nasty.. worth about $30 (US).
It produced some nice results, that were always the right exposure.. even with different ISO film.. My question is this: what mechanism do they use to meter these photo's correctly? Is it modified when developed?
3) What camera's/lenses do professional sports photographers use, and how much do they cost? Do any of them still use film?
4) One more question.. What is the most expensive production lens that one can buy? Just out of interest of course..
Thanks in advance for any answers,
Cheers, Dan.
Message edited by author 2004-06-10 21:18:02.
|
|
|
|
06/11/2004 02:49:48 AM · #2 |
|
|
|
06/11/2004 08:52:31 AM · #3 |
| I think the answer to your first question is that the smaller apertures (the higher f numbers) require a more precise mechanical device which is more expensive to produce. My Minolta A1 will go to f9, f10 and f11. Does anyone know of one that will go to higher f numbers without using interchangable lenses? |
|
|
|
06/11/2004 09:11:44 AM · #4 |
Originally posted by dhare:
1) Why do compact digicams rarely have lenses that stop down more than F/8? Surely it's not hard to increase the amount the aperture closes? |
I think a lot of it has to do with how tiny the lenses are. Remember that larger f-numbers mean smaller openings to let light in. With a mechanical device, there is only so much control you have over positioning the aperture blades down to a precise size. With the size lenses that are used in P&S cameras, moving from f/8 to f/11 may requiring positioning the aperture blades only a few millionths-of-an-inch closer together, something not likely to be achievable in "low cost" cameras. It is easier with larger 35mm lenses because everything is "bigger".
Originally posted by dhare:
2) When I was younger, I remember I had a point and shoot film camera, cheap and nasty.. worth about $30 (US).
It produced some nice results, that were always the right exposure.. even with different ISO film.. My question is this: what mechanism do they use to meter these photo's correctly? Is it modified when developed? |
Absolutely. Film (especially print film) has a tremendous amount of exposure latitude. All film that is submitted to those overnight/1-hour places for processing is heavily adjusted during creation of prints (see, for example, Kodak's PerfectTouch(tm) processing)
Originally posted by dhare:
3) What camera's/lenses do professional sports photographers use, and how much do they cost? Do any of them still use film? |
A lot of long Canon L glass and EOS 1-series digital cameras. When you watch sports on TV, watch the sidelines for photographers and see how many white lenses you see. A few months ago, I saw a Canon ad that showed a picture of the sidelines at a big tennis tournament. There were about 40 photographers all huddled together, capturing the action. The tagline on the ad said "We count 37 Canon lenses in this picture" or something to that effect, showing how they are dominating the sports market (even moreso now with the release of the 1D Mark II.)
Also, take a look at this article about Sports Illustrated's digitial workflow. At the top of page 2, you'll see one photographer working out of at least 6 camera bags. A little further down, you'll see all that long Canon L glass that I'm talking about. I'm not very good at identifying lenses from photos, but those look like 400mm/2.8L IS, 500mm/4L IS or 600mm/4L IS lenses. (At B&H, those lenses sell for US$6500, US$5500 and US$7200, respectively.) Oh yeah, and a 70-200/2.8L IS around the one guys neck and a couple more cameras on the ground with some wide-angle lenses for when the action gets close. And at the bottom of the page, you'll see that they still do use some film -- in this case, remote-controlled medium format Hasselblads. I would guess that very little 35mm film is used any more.
Originally posted by dhare:
4) One more question.. What is the most expensive production lens that one can buy? Just out of interest of course.. |
The Canon 1200mm/5.6L is "made to order" (i.e., not in stock at B&H) and costs around US$80,000 last I heard... you can see pictures of it here used on a Canon MiniDV camcorder (Canon's EF lenses can be mounted on some of their camcorders as well.)
Message edited by author 2004-06-11 10:07:45. |
|
|
|
06/11/2004 09:55:14 AM · #5 |
Q1:
As EddyG mentioned then it has to do with lens diameter (see his explanations). This diameter and censor size ratio also makes f/8 very deep DOF on compact camera while f. inst. f/8 on 35mm camera with 300mm lens makes the DOF shallow.
Q3:
Don´t know exactly what lens is most popular in professional sports photography (probably depends a bit on what sport you are dealing with) but mostly there are high quiality glass, fast telephotos (at least 3-400mm, many of thouse big whites are 5-600mm). |
|
|
|
06/11/2004 10:41:14 AM · #6 |
Q1: With smaller apertures, you start to lose sharpness due to diffraction effects. That's why lenses are NOT at their sharpest when stopped all the way down. Small sensor digicams may have a something like a 7mm lens. To get f8, the aperture needs to be 0.875mm in dia.
|
|
|
|
06/11/2004 07:28:37 PM · #7 |
| Thanks for the replies... that 1200mm is a beast |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/11/2025 05:55:43 PM EDT.
