Turn lens IS off when shooting at high frames per second?

[digiquisitive]

If I am shooting my EOS 7D2 at 10 fps in AI Servo, using (for example) Single Point Expansion and AF Case 6, with Tv at 1/1250th,  should I turn off the IS feature on my 300mm f/4L IS lens?  Why or why not? If the camera is tracking a subject and shooting at 10 fps, seems  to me the lens will have to adjust focus 10 times in each second of shooting.  Will this adjustment be hampered or helped by leaving IS turned on on the lens?  Will IS actually be adjusting right along with focus (as a part of focus)?  Does this have the potential to slow the burst rate down?  Potential for less-than-optimum sharpness shots?  Just for reference, I always shoot handheld, even (or especially!) under these conditions. I can find no advice or discussion on this topic, but it seems highly relevant.  Thanks to whoever would like to opine on this.

[Waddizzle · Accepted solution]

EF 300mm f/4L IS USM lens?

At 1/1250 shutter speed, it may not make any difference if IS is enabled or not.  Some lenses have IS mode settings, which are designed specifically for panning, instead of camera shake.  BUT, ...  

But, the AF sensor may benefit from the IS system being enabled, because the IS can help to minimize camera shake, presenting a more stable imaging data to the AF system.  Seeing how the lens only has IS for camera shake, I might be inclined to leave it turned off, and keep my shutter speed high.

The 7D2 also allows you to adjust 1st and 2nd Image Priority.  Adjusting these for full tilt Image Priority can make a world of difference in your keeper rate.  By forcing the camera to get a focus lock before firing the shutter means every shot will be in focus on something, and more times than not it will be your subject.

True, setting Image Priority to Focus can potentially slow down the frame rate.  How much it can slow down FPS depends upon your tracking skill, AF settings, and ultimately the focusing speed of your lens.  But, what good is 10 FPS if most of the shots are OOF?  I would rather settle for 6-9 FPS, and know that all of the shots are in focus.

[ebiggs1 · Accepted solution]

I have the EF 300mm f/4L IS USM Lens and it is a fantastic lens.  But back to your question.  I don't think it makes any difference.  IS is not going to help you as much as the SS gets quicker.  I think you may believe that IS turns on and shuts off with each click at 10 fps but if you will notice while you are shooting just one shot the IS remains active a moment afterwards.  The same thing will happen with higher fps.  Personally I see no difference using IS or turning it off.  Same thing for the lens on a tripod.  I see no difference either way.  It is an easy thing to verify for yourself.  You know what to do!

Most folks have a misconception about IS.  The fact is, it works best at faster SS.  It works less and less as SS gets slower and slower. It also depends on the person as SS slows.  Some will be able to use it at slower SS than others. You hear claims in the advertisement of a 2 to 3 stop or a 3 to 4 stop, whatever, advantage.  Well which is it ? 2 stops or 4 stops ?  So, it is a variable benefit.

[amfoto1 · Accepted solution]

The EF 300mm f/4L IS USM is one of my most-used lenses. In fact, I use it so much I have two of them. I love the size, sub-3 lb. weight and overall performance of it on both APS-C and full frame cameras. It works very well with a 1.4X teleconverter and has almost as good image quality as the EF 300mm f/2.8L IS USM.

I use the 300mm f/4 almost exclusively handheld and I can't recall the last time I turned off IS. I don't think it matters a bit, as far as AF speed, shutter speed and gerneral performance are concerned. Occasionally I put it on a monopod for extended shooting (more than two or three hours). But I never use it on a tripod (while I almost always use the 300mm f/2.8 on a tripod).

The reason I mention that is because the 300mm f/4 was one of the first to have IS and still uses the rather "primitive" form of IS that can go wonky on a tripod or any time there's absolutely no movement for the IS to correct. It can go into sort of a feedback loop where the IS is actually causing image shake. The 300mm if/4 IS is the last lens remaining in the Canon line-up that doesn't "self detect" lack of movement and turn IS off automatically itself (the EF 28-135mm and original version of the 24-105L were the other two, but were retired the last year or so.... one or two others with similar IS have long ago been discontinued.)

This never happens, though, when handholding or using it on a monopod. Even on a tripod with a gimbal mount that's usually enough movement to keep the lens' IS working happily and out of trouble. And this lens simply lends itself to handheld shooting. That's one of the primary reasons why I use it so much... it's easy on my arms while leaving me as mobile as possible.

Something else... I think IS can help stabilize the image in your camera's viewfinder. That can be helpful when shooting moving subjects even when using faster shutter speeds. 

Years ago I posed some questions about IS to Chuck Westfall at Canon and he told me that with a few exceptions, the primary reason the lens manuals recommend turning off IS when using a tripod (or a fast shutter speed) was to save a little battery power. But in my experience using IS lenses for going on 20 years now, the IS really doesn't draw very much power. So I rarely turn it off on this or any other lenses. Another I use (28-135mm, two copies) has similar tripod issues as the 300mm f/4 IS, but all the other IS lenses I use self-detect and that seems to accomplish the same power savings as if I remember to turn it off manually.

P.S. It seems to be different with Nikon's VR. Many users feel that it slows AF performance and there seems to be some evidence to support that. Based on my years using them, I don't think this is the case with Canon IS lenses. But I also haven't done any kind of carefully controlled, scientific testing of it, either.

Oh, and like Wadizzle, I'm using 7D Mark II and have fiddled with the Focus Priority settings. I have them dialed all the way up, since out of focus images are of little use to me. That can cause a slight shutter release delay or slow frame per second rate during bursts a little... but those aren't a problem for most of what I do. (I can see where someone like a photojournalist might set the exact opposite, shutter release priority high versus focus accuracy. But that's not me.)

***********

Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2) some other cameras, various lenses & accessories
FLICKR & ZENFOLIO 

[cicopo · Accepted solution]

Having the IS on has not slowed my cameras down. I shoot fast paced action & my frame rate is 10 FPS every time i've checked the files. (7D2, 1D4, Canon L's or the Sigma 150-600C). Most recent check was just a week ago.

[digiquisitive · Accepted solution]

Thanks, Wadizzle, for the good and prompt reply.  Yes, the lens is USM -- you're right. Thanks for the suggestion about shutter release priority settings -- several people who responded agree with you -- so I have changed to full-bore focus priority.  And one of the respondees provided info about the vintage IS system in this 300mm lens.  I asked Canon some time ago if this lens is in line for an upgrade, but tech support is not privy to that kind of info.  I'll be one of the first in line to get a new version, if offered.  I almost always shoot this lens with the Canon 1.4x attached, and the results are excellent. For now, based on your and others' recommendations, I'm leaving IS turned on -- one good reason I just thought of this morning while out shooting is that I really want IS active all of the time, and I take more stills than bursts.  Thanks again. 

[digiquisitive · Accepted solution]

Thanks VIP ebiggs1!  Excellent points.  I agree about the excellent quality of the lens, but am hopeful Canon will upgrade it soon as it has with so many other mainline L lenses. Interesting point you make about IS working better at faster SS.  You  left one thing out, though -- as we get older, we slow down, too, and we are less  agile and have poorer responses!  I know all about that. Maybe a more agile IS system in a new 300 L lens will be of some benefit to those of us with a lot of gray hair (been shooting for 65 years)!  I am responding to all 6 people who replied to my question, if you are interested in reading those. Thanks

[digiquisitive · Accepted solution]

Hello, Alan, and thanks for the detailed response.  I almost always shoot my 300 with Canon's 1.4x extender.  Dynamic duo!  As I mentioned in my response to Wadizzle, I asked Canon about replacing the 300 f/4L IS, and Tech Support said they are not in the loop with that kind of information -- hope it happens soon.  Since you mention the archaic nature of the IS in the lens, I'll tell you that when shooting that lens and 1.4x combo on my 7D2,  there is a noticeable difference in the burst rate of the camera when compared to shooting the same camera with my 70-200 f/4 L IS lens. Scary!  The camera slows down to maybe 8 fps or less with the 300+1.4x,  but rips off a whole lot more fps when the 70-200 is mounted. As I told Wadizzle, you guys prompted me to push the 2d image priority to focus instead of middle (compromise) position.  Thanks for that, and all of the rest.

[digiquisitive]

Nice RC shot!  Thanks for sending.  Point of clarification, please: I assume you mean you use 65-point automatic selection in the full AUTO configuration (you do not use the single AF point implanted in the viewfinder with the other two non-AUTO options -- AF tab 4, item 6, choices one and two), which means the camera both chooses and tracks what it identifies as the subject. That's why you move to an Expansion AF Point mode when concerned about conflicting/confusing backgrounds, right?  You may find this of some interest: I shot some Canada geese yesterday when they were first in  the open sky, but then they flew across a background of fir trees, and wove in and out of a group of trees that were between me and them -- the tracking never wobbled, always kept them in focus irrespective of the changed background or intervening foreground (I have Tracking Sensitivity set at -2, which is "lock on and forget what else comes into the VF").  I was shooting with 4-point Expansion AF and AI Servo.  Thought you might find that of interest.  I can see the advantage of having all 65 AF points available for tracking, but am concerned about most of my subjects not being the sole or closest object to be automatically identified as the subject, then tracked -- that's just the kind of stuff I normally encounter when I go out.  I can see the advantage of 65-point auto in your RC shot. Thanks again.

[digiquisitive · Accepted solution]

Hello, Alan, and thanks for the detailed response.  I almost always shoot my 300 with Canon's 1.4x extender.  Dynamic duo!  As I mentioned in my response to Wadizzle, I asked Canon about replacing the 300 f/4L IS, and Tech Support said they are not in the loop with that kind of information -- hope it happens soon.  Since you mention the archaic nature of the IS in the lens, I'll tell you that when shooting that lens and 1.4x combo on my 7D2,  there is a noticeable difference in the burst rate of the camera when compared to shooting the same camera with my 70-200 f/4 L IS lens. Scary!  The camera slows down to maybe 8 fps or less with the 300+1.4x,  but rips off a whole lot more fps when the 70-200 is mounted. As I told Wadizzle, you guys prompted me to push the 2d image priority to focus instead of middle (compromise) position.  Thanks for that, and all of the rest.

[digiquisitive]

See my 3-24-2015 item on this topic. My 300mm still sometimes requires me to kick start it manually to get it into approximate focus before it wants to home in. Problem has been with me for 3.5 years -- at least. Was probably there with the old 7D, as well. Time for an upgrade, Canon.

[cicopo]

All points active works well for me since my targets can change direction quickly & are usually up against the empty sky. Some are also very fast so just keeping them in the viewfinder can be a challenge.  See my reply here.

https://community.usa.canon.com/t5/Lenses/28-300-Zoom/m-p/252379#M13908

[digiquisitive]

Thanks, cicopo. Very nice work. And I liked the info at the link.

[ebiggs1]

" It can go into sort of a feedback loop where the IS is actually causing image shake."

I don't know if this is happens or is even possible.  All I can say it has never happened to me.

[ebiggs1]

 I have a great number of Canon lenses. I don't have every lens' manual here in front of me. But the couple I do have at my computer desk say, "When you use a tripod, the Image Stabilizer should be turned off to save battery power."  That is all I can see.

If they sensed a tripod, there would be no need to manually turn IS off.

[digiquisitive]

Thanks for all of your help.  Old guys rule!