one more time canon 100-400 IS

[adrian mandea]

ok guys, new development in the IS story....i did one test because i am still not satisfied with this lens.so here goes:


canon 40D ,canon 100-400mm IS iso 100 f8 (don't know if it is important ) ,i set them on the table to be perfectly still (don't have a good tripod so this is much better) and using the wire remote I began to focus on some things in the house WITH the IS ON in position 1 .(all 9 focus points were selected)Looking thru the viewfinder but being carefull not to touch the body I can clearily see how for 3-4 seconds the image shifts from left to right slowly and then stops.I did the same test at 2m and 7-8 m ,the same thing happened.Is this normal?can someone do the same test (maybe with a similar body)and post the results?


thank you very much

[neuroanatomist]

Not a good test of IS. The point of IS is that it's designed to stabilize a moving camera. The IS in the EF 100-400mm is tripod-sensing, meaning if the camera is very still (as it would be on a good tripod, or sitting on your table), the lens actually turns the IS system OFF.


What you want to do to test IS is take a picture of something with IS off at a shutter speed which you can (barely) hand-hold the lens, e.g. at 400mm and 1/500s, and take a picture. Then, adjust your ISO setting so your shutter speed is 2 stops slower (1/125s in this example) and take another picture - it should be significantly blurry. Then, turn IS on and take the same picture. If it's as sharp (or nearly so) as the picture at 1/500s, then your IS is working as it should.

[adrian mandea]

thank you very much for the tip,i'll do that .i know the IS is not supposed to work in this case that's why I think is not working well.my lens was made in 2006 so maybe it is an old tipe of IS, i don't know.it's true that the weight factor counts a lot in this case, the lens is HEAVY,is not fair to compare it to the 70-300mm IS which is very light and easy to use, but I still think the lens can do better.


thank you all for the advices





adrian mandea

[Sinh Nhut Nguyen]

Keep in mind that you're shooting with a 1.6x crop body, so 400mm is actually 640mm.

[adrian mandea]

I don;t want to create a new topic so I'll ask this here:


how is the IS mode 2 on the 100-400mm L working? I know it's for panning and it will correct the vertical movement but what about if I shoot in portrait orientation? (I know is not usual to do so but never know) will it work or will it just ruin my pictures?





thank you

[neuroanatomist]

The short answer is that mode 2 IS works for panning with the camera in either the landscape or the portrait orientation.


The long answer I'll copy from a [url="http://www.openphotographyforums.com/forums/showthread.php?t=1919]2007 forum post[/url] by Chuck Westfall (the person who write's Canon's TechTips newsletter):
<div class="post"]
<div class="posttext"]Every Canon SLR lens that has an Image Stabilizer built in has two so-called "gyro sensors" oriented at right angles to each other. With this design, the level of IS functionality is the same whether the camera is in landscape or portrait orientation. When the camera is in portrait orientation, the level of IS functionality is the same whether the hand grip of the camera is on the top or the bottom.

In all of these cases, IS lenses that have a Mode 2 setting operate as follows when Mode 2 is selected: Both gyro sensors sample the direction and amplitude of lens shake simultaneously and continuously whenever the IS system is activated. The resulting data is analyzed by a dedicated microcomputer in the lens, and that microcomputer in turn controls the behavior of the electromagnets surrounding the movable optical components of the IS lens. These electromagnets are also oriented at right angles to each other. If the lens is set to Mode 2 *and* the microcomputer determines that intentional panning is taking place, it shuts off stabilization in the panning direction regardless of camera orientation. If, on the other hand, the microcomputer does not detect intentional panning, then horizontal and vertical stabilization is executed simultaneously, just as it is in Mode 1.

Canon anticipates that in most cases, the camera and lens will be held either horizontally or vertically, in order to keep horizon lines straight in the resulting picture. In such cases, the typical behavior of the IS system is covered by the explanation above. If, on the other hand, the panning direction is diagonal with respect to the orientation of the gyro sensors, and Mode 2 is selected, there is a possibility that the level of panning detected by each gyro sensor will be sufficient to cause the microcomputer in the lens to shut off stabilization in both directions at once. Since the decision to shut off stabilization in Mode 2 is made by the microcomputer, there is no overt way for the photographer to control it.

Let me know if this helps to answer your question.

Best Regards,

Chuck Westfall
Director/Media &amp; Customer Relationship
Camera Marketing Group/Canon U.S.A., Inc.</div>
</div>
<div class="post"]
<div class="posttop"]</div>
</div>

[adrian mandea]

thank you John ,you really know everything.see you at the next question...I hope

[jcrowe87]

The IS in the EF 100-400mm is tripod-sensing, meaning if the camera is very still (as it would be on a good tripod, or sitting on your table), the lens actually turns the IS system OFF.

I do believe you are wrong here, this early system isn't actually tripod sensing, though most of the newer ones are. According to the manual included with the 100-400, shooting on a tripod with the IS system engaged can "introduce errors". I totally agree with your recommended test, just thought I would clear this up.


Jordan

[neuroanatomist]

I do believe you are wrong here, this early system isn't actually tripod sensing

Thanks for clarifying. Bryan's review of the 100-400mm states, "While the 100-400 L's IS system will detect a tripod and automatically disable itself, turning off IS when using a tripod will save a little battery life and cause the IS mechanism to be locked in a centered position," so that's what I based my answer on.


I won't have my very own instruction manual until Monday, when it arrives with my brand new EF 100-400mm f/4.5-5.6L IS USM lens. []

[jcrowe87]

Well then woohoo for Monday!