IS and long exposure blur in photography

So I have been bitten by the photography bug recently.  Tried my hands on an Xsi last year during the Montreal Canadiens’ training camp and missed playing with a DSLR so much that went out and got myself a Canon T3i (600D). Entry level or not, I simply love that camera.  I got it with the kit lens and also got a 70-300mm f/4.0-5.6 IS USM lens along with it for sports photography mainly.  The zoom lens, while not top of its class, is relatively expensive (going for $779.00 in the Canon store, but can be purchased for about $600.00 or so at Amazon) than other zoom lenses out there and produces some very sharp images.

I have been trying different photography techniques to learn as much as possible about my camera and improve my photography skills to capture good photos.   I have come to realize that long exposure / night photography is a lot of fun.  So while trying long exposures, I ran into a problem where my images were just not coming sharp and full crop of these images showed severe blurriness more often than not.  I was following the guidelines, using a tripod, and using delayed shutter release in lieu of a remote, locking the mirror before the shutter release to eliminate any vibrations caused by the mirror going up, but I was not succeeding.  Here are a couple of examples where by chance, 1 out of 5 exposure did come out nice and sharp, but most of them came out blurry.

Long Exposure, 30 seconds at F10, shows blurriness in the image, even with a delayed timer

Now the above photo shows pronounced blurriness.  The camera was secure on the tripod. I used the kit lens, 18-55mm IS, that came with the T3i and I used a 2 second delayed timed shutter release.  I also locked the mirror, although it should not have been necessary as I was shooting in live view mode.

Long exposure - 30 seconds at F11 - full crop shows a sharp image with no apparent blur.

In this example above however, the photo came out very sharp.  Yes the apperture was a bit smaller than the previous photo, but this seems like a chance picture.  I took 5 different exposure of this building and this was the only one that came out sharp.   I proceeded to take other photos as well that night, not really zooming in to check how sharp the images were when previewing them.  It was only after I opened these photos in Lightroom that I realized that these were not sharp at all, luckily I did get one that worked.  Now the question was, what was causing the blurriness.

I posted the issue on POTN (Photography-on-the.net) forums and the kind hearted folks there tried to come up with solutions, or possible causes for this occurence.

One of the major reason that I heard from everybody was “Cheap tripod”.  Granted I am using a relatively inexpensive tripod, but it is not as flimsy as the words “cheap tripod” make it sound like.  In fact, I have taken some nice sharp pictures with my 70-300mm (long exposure) with the same tripod.  The lens is much heavier than the 18-55mm kit lens.   Cheap tripod that may succumb to vibrations in the ground or some movement, or even breeze could be a problem, but here, it didn’t seem like that was the case.

The other major reason  -  I clicked the button.  Yes, I used the delayed timer shutter release instead of using a remote shutter release.  That can cause vibrations and result in the blurriness.  It was a fair assessment and I think pressing the shutter does result in some vibrations that may cause blurriness.  Some even said I should have used a 10 second delayed timer instead of the 2-seconds that I used in my photos above, only to ensure that the vibrations induced by pressing the button could dissipate before the shutter actually releases and the exposure begins.

In addition to these two reasons, the major one was Turning the IS off on my lens.  Image stabilization on the lens is great when holding the lens in your hands but not on the tripod.  This was echoed by many who responded on the forum and it made sense for me to try and test this.  At the same time, someone had suggested to me that I should use the EOS utility that comes with Canon along with a laptop and use that as a remote to take my long exposure shots in the absence of a proper shutter release remote.  So I went out to test the theory.  Here are the resulting 8 images:

All of the above images were taken in absolutely similar conditions.  Nothing was changed.  As you can see, when using a remote, the image came out to be very sharp, even with IS on.  Now to really see if the IS was the culprit, four more pictures using the similar settings but with IS off were taken.  It’s important to note that the camera is still sitting on my relatively inexpensive tripod.

No questions asked, this is absolutely clear, pressing the button, the cheap tripod, the delayed shutter release, using a remote, all that, while valid reasons, were not the ones causing the blur in my photos, it was rather the IS system on the lens that was doing that.  Turning the IS off reduced the blur completely in all conditions.  I’m going to assume that pressing the button causes vibrations in the camera and the IS, when active, tries to compensate for those vibrations to stabilize the image, but what it does becomes counter-productive to the photo as the camera is already stabilized.   This in turn causes blur in the pictures.  Remember, when IS was on, using a remote resulted in a really sharp image as no vibrations were induced in the camera due to the button press.

So folks, moral of the story, turn the IS off on your lens if you are using a tripod.  There’s no need for it.

Here’s a shot I took a few days ago from Mount Royal, it shows the lovely city of Montreal.  I remembered to turn the IS off and used another tip I picked up in my research:  I zoomed in while using live view to focus on something to ensure I get a sharp image.  If you didn’t know that, while using live view for shooting, you can zoom in by pressing the zoom button on your camera up to 10x.  This allows you to manually focus with precision.

Ville de Montreal

I hope that this post will help some other newbie photographers like myself.

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