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Focusing with 100-400mm lens and Canon 7D (1 Viewer)

Craig Thayer

Well-known member
Because the price on 7D body is currently $1199 US I am considering purchase in next few days (currently own 40D) but am concerned about some reviews I have read indicating that autofocusing with the 100-400mm lens is not as good with 7D as 40D. Since I know there are many people on this forum using the 7D/100-400 lens combo, comments are welcome !

Craig Thayer
 
Hi Craig,

I use 7D with 100-400 having upgraded from a 30D. I can't say I've noticed issues with AF using the 7D - can you elaborate?

I would be interested in understanding what these reviews say relating to which modes/settings.
 
Likewise, another happy 7D / 100-400 user here (and definitely pleased with the 7D as an upgrade from the 50D I had before). Haven't seen any adverse comment elsewhere, either - what are you referring to?
 
My feelings about the 7D and 100-400 is that the lens (my copy) is not really sharp enough wide open to bare scrutiny at 100%, and if there is (fast) movement in the frame then the demands are even greater. But if you are more interested in shooting pictures than pixels I really don't see a problem.

Here are some examples of which the only edits are cropping. The first three are wide open at 400mm, then wide open at 285mm and finally 170mm at f/6.3. ISO values range from 200 to 3200 with three of them at 800.
 

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While contemplating whether to purchase 7D , when using Google for research I saw comments on various websites regarding the autofocus issue. After I posted on this forum I asked same question on a photo forum(www.dpreview.com) and some members indicated autofocus can be a problem the might be corrected with microadjustment.

However my overall sense now is that since I photograph only for personal enjoyment(non-commercial) I should purchase the 7D although another option is to wait for the rumored Canon 7D Mark II later in 2013 (birthday present to myself in April? )
 
Lots of issues reported in forums as being "camera" problems are often determined to be operator error. I would include failure to check AF calibration and adjust as operator error. You don't expect a car(automobile) to perform well with incorrectly inflated tyres(tires) and there is no reason to expect a camera/lens combination to deliver its best results if not set up properly.

This is always a good read for those who don't appreciate these things....

http://www.lensrentals.com/blog/2008/12/this-lens-is-soft-and-other-myths

Other operator problems would include inadequate shutter speeds, especially when pixel peeping, poor shutter release technique, inappropriate IS mode, lens used at non-optimum apertures, unrealistic expectations at high ISOs, poor processing skills, fitting any filter to the 100-400, pixel peeping.

The 7D has all 19 AF points cross sensitive with f/5.6 lenses, which should put performance well ahead of the 40D when using points other than the centre point, but having 80% more pixels squeezed onto the same size sensor means that each and every pixel has the capability to embarrass both the lens and the photographer if all aspects of the photographic process fall short of perfection.

That isn't to say that there are no faulty 7D bodies out there, but I bet quality control is more variable in the human race than in cameras coming off Canon's production line. I know the 7D required me to improve my skills in order to get the best from it. There's still plenty of room for improvement too.
 
Thanks for all answers

On my 40D I often just use center point focus(in part based on comments on this forum). On 7D is using only center point not a viable option to obtain good quality bird photos ?
 
Thanks for all answers

On my 40D I often just use center point focus(in part based on comments on this forum). On 7D is using only center point not a viable option to obtain good quality bird photos ?
Yep, using just the centre point is also good on the 7D - in addition to just the normal centre point you also have spot AF which is a smaller spot than usual for precision work (birds eye....). You also have single point expansion which is good for birds-in flight. There are also other AF options on the 7D that are not available on the 40D.
The AF system on the 7D is the number one reason for anyone to upgrade from a 40D IMO.
I have a 7D and a older 40D but the 40D is relegated to a second body/backup Camera these days as the 7D is superior in almost every respect IMHO.
 
Craig,

Another piece of functionality worth exploring on the 7D is the ability to alter the tracking speed of Al Servo. The AF sensitivity can be adapted for shooting BIF, something I certainly couldn't do with my 30D.
 
Yep, the AI servo sensitivity speed comes in very useful for flyers. It does not effect the actual tracking speed or initial lock but determines the time the AF takes to lock onto something else if it loses focus on the bird. With a slow sensitivity setting it will give you time to get back onto the bird before it locks onto something in the background. I always use this with single point expansion for flyers against a busy background BUT for birds in flight against an uncluttered background zone AF with a fast AI servo sensitivity setting works brilliantly.
This is just another few examples of the superior AF system of the 7D.
 
One feature to mention explicitly is the per-lens focus adjust. I put a focus target on a board tilted away from me and test for front-focus and back-focus. here's a website with the chart I use. http://focustestchart.com/focus21.pdf. there's apparently a new version I haven't worked with, but the idea is simple enough. I found the camera always had the point of focus in good focus, but the depth of field range wasn't perfectly centered on the point of focus. the per lens adjust (need latest firmware which is easy to download if your camera doesn't come with it) allows each lens to have it's own adjustment. Didn't need an adjustment for my longer lenses. Only needed it for a 17-40 near-wide angle zoom. Even there, it was focusing well enough that the point I had selected for focus was well in focus, but not perfectly centered. Adjustment improved it but didn't get it absolutely perfect. Overall, I was happy and this is a feature I associate with higher end cameras.

Based on the pattern of deep discounts, I'm guessing we'll have a new 7D mark II soon. I bought knowing that was likely and I'm ok being a couple of years behind. I'm happy with the 7D so far.

I think APS-C sensor is an advantage relative to full frame for birding, becasue the extra depth of field provided by smaller sensor. Focus on long lenses is always a major challenge.

7D traditional phase detect autofocus will not work on f8 configurations, such as a 2X teleconvertor on an f4 lens. However, the live view contrast seeking autofocus will work. I tested this. I wouldn't expect to use this often, but on a relatively still target quite far away it might be my best option (or manual focus).
 
7D traditional phase detect autofocus will not work on f8 configurations, such as a 2X teleconvertor on an f4 lens. However, the live view contrast seeking autofocus will work.
I have even had AF via live view at f16 on the 7D (f5.6 lens + 2x tc +1.4x tc) you do need very good light and contrast though. I sometimes shot a 400/5.6 + 2x tc (f11) - AF can be very accurate although slow compared to normal phase AF and you need a tripod for this type of work. I always found with live view AF that it paid to roughly manually focus and then let the contrast AF finish the job.
 
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