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DPChallenge Forums >> Hardware and Software >> 100-400mm f4.5-5.6L IS USM
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Showing posts 26 - 42 of 42, (reverse)
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 06/02/2004 06:12:15 PM · #26
Originally posted by garrywhite2:
Found my first dust on the sensor after using the 100-400 on a mild windy, slighty dusty environment. The dust may not have been caused by the push/pull though. I saw an opportunity to use my 28-135 and switched lenses. I tried to do this carefully, and inside my vechicle..but you never know for sure. I'm usually very careful about changing lenses. I've had the camera for about six months through a variety of situations and have changed lenses countless times... and this if the first dust I've spotted dust on the sensor.


Ok, I am confused now.

If the lens does suck in dust, and I am not convinced that is not a myth that has become self perpetuating with everyone saying it as they have heard others say it etc, how does that dust get to the sensor in the camera? (genuine question, not a loaded one).

If a lens does suck in dust, would it not suck it into the actual lens body and it would accumulate between the reaf and front elements but WITHIN the actual lens? I can't see how that dust then gets to the camera sensor.


06/02/2004 09:16:56 PM · #27
Good points Simon. I think it's most likely mine came from dust in the air that had not settled, or dust around the lens mount.
 06/02/2004 09:39:51 PM · #28
I absolutely love my 100-400mm lens and wouldn't trade it for anything. The push pull zoom took a bit of getting used to, but now I really prefer it.

As far as dust goes, I don't think Eddy's concerns are unfounded, however I use this lens all the time at the motocross track and dust hasn't been an issue yet.

A shot taken this past weekend: Lizard 1 and Lizard 2

Edit: Spelling

Message edited by author 2004-06-02 21:40:20.
 06/02/2004 10:31:45 PM · #29
Originally posted by Natator:
how does that dust get to the sensor in the camera?

First, realize that each optical element in a lens does not create a bunch of small "sealed chambers" between them. So air can move freely from the front to the back and everywhere else in between.

Second, a push/pull zoom by design has to allow air to be "forced out" (i.e., it can't be air-tight) otherwise it would be impossible to compress the air and have the lens stay zoomed out (it would want to "spring back"). Likewise, it has to let air in, otherwise you'd create a vacuum when zooming. So air (and whatever particulates are in it) is going to be sucked in to the lens. This contrasts with an internally-zooming lens design (like the weather-sealed 70-200/2.8L).

Finally, since the lens is not sealed at either end, it is entirely possible for particulate material to be sucked in through whatever air openings exist and then eventually deposited on the sensor (since there is no seal between the rear lens element and the lens mount opening). The constant flapping up/down of the mirror ensures lots of opportunities for small particulate matter to be "stirred up".

(Push/pull zooms are sometimes referred to as "dust pumps". =)
 06/02/2004 10:50:54 PM · #30
Does anyone know how the new EF 28-300mm f/3.5-5.6L IS USM stacks up against all of these lenses?

Any thoughts/experiences, As this looks like the lens I would buy next...
 06/02/2004 11:18:59 PM · #31
Originally posted by EddyG:
First, realize that each optical element in a lens does not create a bunch of small "sealed chambers" between them. So air can move freely from the front to the back and everywhere else in between.


Ok, did not know that.

But, would there still be an air passage from inside the lens, through the very back (as in camer end, forgive the lack of technical terms here) lens, and into the actual camera body.

I had always imagined that back lens at least would form an air tight barrier against the camera body.

Oh, and tfaust ...... have I got an American twin? Most of my recent photos have been motocross and lizards *laugh* I absolutely LOVE those lizard shots by the way!
 06/03/2004 12:21:00 AM · #32
Originally posted by wimbello:
Does anyone know how the new EF 28-300mm f/3.5-5.6L IS USM stacks up against all of these lenses?

Any thoughts/experiences, As this looks like the lens I would buy next...


Not very good and quite expensive (US$2500). Check out this Luminous Landscape review. IMHO You'd be better off getting 2 or 3 lenses to cover the range.
 06/03/2004 07:19:37 AM · #33
I had a chance to test the Sigma 120-300mm F2.8 lens today, I found it very fast and very sharp. But unfortunatly it's too heavy for me. I don't think I've ever tried a so heavy lens before. It's HUGE.

But if you're man for it, then this is the lens for you.

06/03/2004 07:25:38 AM · #34
Originally posted by terje:
I had a chance to test the Sigma 120-300mm F2.8 lens today, I found it very fast and very sharp. But unfortunatly it's too heavy for me. I don't think I've ever tried a so heavy lens before. It's HUGE.

But if you're man for it, then this is the lens for you.


I was curious after you posted this and looked up the weight of that lens - 5.73 pounds! I had no idea it was THAT heavy. Almost twice as heavy as the 100-400L, and that one is not light (for handholding anyway) at 3 lbs.

Of course, monsters like a 600mm F/4L weigh something like 12lbs, so I guess it is all in what you are used to.
 06/03/2004 11:25:12 AM · #35
Originally posted by Natator:
Oh, and tfaust ...... have I got an American twin? Most of my recent photos have been motocross and lizards *laugh* I absolutely LOVE those lizard shots by the way!


Thanks Simon! Based on what I see in your portfolio, I'm honored :-) I would love to shoot the types of motorcycle racing you have. As it is, the dirt MX track I go to is pretty close to where I live, so it's been a great place to practice and make a little bit of side money. Not to mention, it's great fun when the riders start showing off for the camera and do tricks. What lens are you using for those motorcycle shots?
06/03/2004 12:40:22 PM · #36
Originally posted by richterrell:
Originally posted by zeuszen:
Here's a bokeh sample image taken with an EF 70-200mm f/4 L:

Exposure time: 1/250 (0.00400)
Shutter speed: 1/250.00
F-stop: 4.5
ISO speed: 200
Focal length: 200.0000
Flash: 0
Orientation: 1
Aperture: 4.3398
Exposure bias: 0.0000

Here are some stats re dof:

@ 200mm f/2.8 focused at 2 m > ca. 2 cm sharp dof
@ 200mm f/4.0 focused at 2 m > ca. 3 cm sharp dof

@ 200mm f/2.8 focused at 4 m > ca. 6 cm sharp dof
@ 200mm f/4.0 focused at 4 m > ca. 8 cm sharp dof

@ 200mm f/2.8 focused at 6 m > ca. 18 cm sharp dof
@ 200mm f/4.0 focused at 6 m > ca. 32 cm sharp dof


Good bokeh indeed - the next lens I purchase will very likely be this one - probably the best bang-for-the-buck "L" glass out there, at least in a zoom.


here's another picture that shows bokeh to help those choosing between the 100-400 and the 70-200. not trying to say one's better than the other, but this is the best example i have of either lens bokeh on dpc.
06/03/2004 03:26:20 PM · #37
Originally posted by nborton:
here's another picture that shows bokeh to help those choosing between the 100-400 and the 70-200. not trying to say one's better than the other, but this is the best example i have of either lens bokeh on dpc.


Good bokeh, and a very good picture to boot.

I have to admit though, I don't really consider these two lenses as really being competitors to each other. They are designed for very different purposes. The biggest separator between these two lenses is the focal length. If 400mm of reach is not an issue then certainly the 70-200mm F/4 is an excellent lens by itself, and one I would want in my bag. If reach IS an issue, and I wanted to adapt a 70-200 to that purpose, the F4 won't really cut it. It slows down too much when doubled with a 2x converter to be very useful as an option.

I like Pitsaman's solution a lot - a 200mm F/2.8L with a 2x converter. He is getting very good results there, and the cost was right on. Almost as sharp as a 400mm F/5.6L, but a lot more versatile, and very cost-effective. Something to consider!
 06/03/2004 04:11:41 PM · #38
Originally posted by richterrell:
Originally posted by nborton:
here's another picture that shows bokeh to help those choosing between the 100-400 and the 70-200. not trying to say one's better than the other, but this is the best example i have of either lens bokeh on dpc.


Good bokeh, and a very good picture to boot.

I have to admit though, I don't really consider these two lenses as really being competitors to each other. They are designed for very different purposes. The biggest separator between these two lenses is the focal length. If 400mm of reach is not an issue then certainly the 70-200mm F/4 is an excellent lens by itself, and one I would want in my bag. If reach IS an issue, and I wanted to adapt a 70-200 to that purpose, the F4 won't really cut it. It slows down too much when doubled with a 2x converter to be very useful as an option.

I like Pitsaman's solution a lot - a 200mm F/2.8L with a 2x converter. He is getting very good results there, and the cost was right on. Almost as sharp as a 400mm F/5.6L, but a lot more versatile, and very cost-effective. Something to consider!


i agree about the fact that they aren't really competing lenses. but, people have mentioned that they are choosing between the two. really it comes down to shooting habits and if you regularly need the extra distance.

thanks for the complement too.
 06/03/2004 04:40:03 PM · #39
That certainly goes against any comparison I have ever done or read about. You can get reasonable results with the 70-200 and the 2x TC but certainly not what I would call close to the 400mm f/5.6L unless of course you are talking about images that have been scaled down to 640x480 lines of resolution or thereabouts.

Greg
06/03/2004 04:53:50 PM · #40
Originally posted by dadas115:
That certainly goes against any comparison I have ever done or read about. You can get reasonable results with the 70-200 and the 2x TC but certainly not what I would call close to the 400mm f/5.6L unless of course you are talking about images that have been scaled down to 640x480 lines of resolution or thereabouts.

Greg


Well, there is a lot of play in the word "almost" :-)

Perhaps I should have said "acceptable" or used yet another word. But the results are pretty good while staying within a pocketbook that may not support other options.

Edit: Pitsaman is using a 200mm F/2.8L and a 2x converter (fixed 200mm, not 70-200mm F/2.8L). I have never seen an in-depth comparison between that combo and a 400mm F/5.6L. I am fairly certain from other examples of using teleconverters that the 400mm F/5.6 would win out in the end, but it would be an interesting comparison to see just how much difference there is.

Message edited by author 2004-06-03 17:10:18.
 06/03/2004 07:09:43 PM · #41
Originally posted by tfaust:

Thanks Simon! Based on what I see in your portfolio, I'm honored :-) I would love to shoot the types of motorcycle racing you have. As it is, the dirt MX track I go to is pretty close to where I live, so it's been a great place to practice and make a little bit of side money. Not to mention, it's great fun when the riders start showing off for the camera and do tricks. What lens are you using for those motorcycle shots?


The ones there are done with a very old (13 years I think), very basic, very cheap 80-300mm Canon lens (forget the exact specs).

A few days later I got my 100-400 L IS USM etc etc etc lens. I have yet to go back to that race track, but have been playing with motocross photos last weekend and got some excellent results :)

Naw though, not honoured at all being compared to me *laugh*

We're just both likard loving bikers ;)
 06/03/2004 07:14:55 PM · #42
I've made up my mind! Tomorrow I'll order the Sigma 100-300mm F4!
I considered Canon 70-200mm F2.8 & IS, Canon 100-400mm IS, Sigma 120-300mm F2.8, Sigma 70-200mm F2.8 AND Sigma 100-300mm F1. And I decided to go with the 100-300mm... Amd I making a mistake? :-)


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