Interesting effect from 100-400 IS

[Longwatcher]

Just curious if others with the Canon 100-400 IS lens have experienced this.

I noticed when playing with the lens this weekend on a tripod attached to my 10D, the image moved slightly up or down as the IS kicked in fully. I was using a remote cable and looking through an Angle Finder C and eliminated my doing something to cause the effect (other then of course pressing the trigger on the remote). Only once did I observe it to go up, the rest of the time it went down slightly.

It took a noticeable amount of time in that I thought the tripod head was not tight the first couple of times.

I was shooting about 50 meters away at a blooming cherry blossom tree (or some kind similiar).

I can only remember noticeing this with the 2x extender on, but then after I had noticed it I wnet back to taking pictures and did not pay any more attention to it.

I suspect that the IS was stabilizing the image on some object in the scene and adjusted accordingly.

Just curious if others have seen this.

[Roger_Cavanagh]

Tim,

You're supposed to turn off the IS when using the 100-400 on a tripod. It gets confused, if there's no movement. The newer IS technology in the 70-200 can work out that its on a tripod and doesn't do this.

And yes, the image floating across the viewfinder happened with mine - nothing to worry about.

Regards,

[Longwatcher]

Good to know it is normal. I suspected it was.

I was on my front porch and the railyard nearby was docking rail cars, not condusive to a stable environment :-o (You should feel it when the shipyard set the island onto the carrier, year before last - Ahh, Life in Newport News :-)
That and I was playing with the lens.

Besides, When I asked Canon what the difference between IS setting 1 and 2 were on the lens (I did not get manual with the used lens) The e-mail reply said 1 was for handheld, 2 was for tripod. Honest, that is the reply I got. (okay it might have been 1 for tripod, 2 for handheld, but I am pretty sure 2 was for tripod).

I have since gotten a copy of the manual which properly explained that one of the modes was for handheld shake, and 2 was for tracking a moving object.

I usually leave it in mode 2, because I almost always mount it on a tripod (that lens gets heavy real quick). if doing stationary targets I will normally leave the IS off. But then again it is a new lens so this is the first time I have had to play with it other then a few (give or take 100) check it out shots.

Got a nice picture of a spider web at about 20 meters, some blossoms of a tree in bloom and a patch of weeds at minimum range (I think I was actually under the hyperfocal distance, but it was focusing so I must have been at least 1.8M away.

I have also learned while using the 2x extender that my current number one complaint with the 10D (and D60) is no focusing screen. I have a slight problem in that my eyes tend to correct for lenses that are slightly out of focus, so manual focus is almost useless for me to try as It will look in focus to me, but still be out of focus. Less of a problem when using the angle finder C, because I can switch from 1.25 to 2.5 mag and if it is out of focus I will not be able to switch and get the other magnification into focus. [I used to be an imagery analyst for the USAF and way back when, the optics on my light table were often the most out of calibration, because I would not notice it until it got real bad]

I personally liked the half circle type I had on my really old Canon AV-1. I never remember getting an out of focus shot with that one (lots of badly exposed ones, but not out of focus).

[Trivia: actually it usually nice in my house, only when a train on the one bad track (about once per week at most) or the shipyard is setting in a new section of carrier does it get noisy or my house shake (usually about once every two weeks near the end of the costruction cycle - nothing since they set the island on the Reagan, but expect them to start setting in sections any month now for the next one]

[Roger_Cavanagh]

longwatcher wrote:
Besides, When I asked Canon what the difference between IS setting 1 and 2 were on the lens (I did not get manual with the used lens) The e-mail reply said 1 was for handheld, 2 was for tripod. Honest, that is the reply I got. (okay it might have been 1 for tripod, 2 for handheld, but I am pretty sure 2 was for tripod).

Makes you wonder, doesn't it? :eyes

Got a nice picture of a spider web at about 20 meters, some blossoms of a tree in bloom and a patch of weeds at minimum range (I think I was actually under the hyperfocal distance, but it was focusing so I must have been at least 1.8M away.

It's a great lens for close-ups. I used enjoy using it that way.

I personally liked the half circle type I had on my really old Canon AV-1. I never remember getting an out of focus shot with that one (lots of badly exposed ones, but not out of focus).

You're right - interchangeable screens would be great.

Regards,

[snoleopard]

longwatcher wrote:
I usually leave it in mode 2, because I almost always mount it on a tripod (that lens gets heavy real quick). if doing stationary targets I will normally leave the IS off. But then again it is a new lens so this is the first time I have had to play with it other then a few (give or take 100) check it out shots.

Got a nice picture of a spider web at about 20 meters, some blossoms of a tree in bloom and a patch of weeds at minimum range (I think I was actually under the hyperfocal distance, but it was focusing so I must have been at least 1.8M away.


Hi,

Two things here, with this lens as Roger mentioned, you should not have the IS turned on in any mode while on a tripod. This can cause blurry images as the lens may get into a slef-feedback loop. The newer style IS on the primes let you use it on a tripod. Search the archives on Rob Galbraith's site for a discussion by Chuck Westfall of Canon. You can damage the lens.

And just a side note the hyperfocal distance of a lens is not the closest focusing distance as you were mentioning. Depending on what zoom and aperture the hyperfocal distance for this lens is several hundred feet away and not a few meters.

And also you can reduce the distance for close focusing by using extension tubes.

It is a great lens.

Alan

[Longwatcher]

snoleopard wrote:

And just a side note the hyperfocal distance of a lens is not the closest focusing distance as you were mentioning. Depending on what zoom and aperture the hyperfocal distance for this lens is several hundred feet away and not a few meters.



I always remembered Hyperfocal distance as being the minimum range at which the lens could focus, if you were closer then that range you would not get good focus. The other end was focus to infinity. Am I remembering this wrong? Or is it a case of Aerial Cameras using different terminology (I have eperienced this before)?

[snoleopard]

longwatcher wrote:
I always remembered Hyperfocal distance as being the minimum range at which the lens could focus, if you were closer then that range you would not get good focus. The other end was focus to infinity. Am I remembering this wrong? Or is it a case of Aerial Cameras using different terminology (I have eperienced this before)?

Hi,

The classic definition of hyperfocal distance is the point of focus where half that distance to infinity is sharp, this technique works best with wide angle lenses as the hyperfocal distance is much closer to the photographer. Here is a link to a calculator for hyperfocal distance:
http://www.mountainstorm.com/HyperFocal/HyperFocal.html

and a place that will generate custom charts for free:
http://www.johnhendry.com/gadget/dof.php

Hope this helps.

Alan