Thank you all for the helpful advice. I have attached two photos I took yesterday of a small green heron. The first is him perched on a structure. Not the greatest photo, but reasonably in focus. The next picture, a few seconds later, is after he took off. The heron's distance from me is almost the same as a moment earlier, yet the heron is completely out of focus. General conditions: Focal length - 300mm; Focus mode - AF-C; AF-Area mode - Dynamic, 9 points; VR on; Aperture - f/5.6; Shutter speed - 1/4000sec; Metering - Matrix; Exposure mode - Aperture Priority; ISO - 2000; Hi ISO NR - on.

When the lens tries to focus I hear a "mmm-mmm" sound of the lens trying to lock on to the subject. It almost always does correctly after a few seconds, so stationary subjects are fine, but if the subject is moving, its has difficulties.

Welcome to UHH Kahunaal!

It probably won't help with the soft image problem, but if your 7D doesn't have the version 2.x firmware installed, you definitely should update it. I used a pair of 7D for over five years (now use a pair of 7D Mark II, but still have the 7Ds as backup). Two or three years after the 7D was introduced, Canon released one of their largest-ever firmware updates for it.... more of a firmware upgrade than they've ever provided for any other camera that I'm aware of. Most firmware updates have minor fixes to address specific issues and don't make very much difference. But the 2.x firmware for the 7D made it behave like a "whole new camera" in many ways. In a sense the firmware upgrade extended the product life of the 7D by a couple years, keeping it competitive against other manufacturers' cameras. It's been some time since I updated mine, but I seem to recall an overall improvement in speed and performance, although a lot of the emphasis discussing the update was on the much increased burst capacity using the same image buffer. It was one of the most worthwhile firmware updates I've ever done to a camera. So look in your menu and see what it's running. If it's any of the 1.x versions, definitely update it to whatever 2.x version is currently available. (If you've never updated firmware before, be sure to follow the instructions carefully. It is possible to "brick" a camera if a firmware update isn't done correctly.)

But I really doubt that will solve the problem with the lens.

As to the 100-400mm lens softness.... Do you have a "protection" filter on it? That particular lens has an idiosyncrasy about filters. Even when a very good filter is used on it, images "go soft". I have no idea why that is.... something to do with the optical formula of the lens, I suppose. But many users who had filters on their 100-400mm "from new", thinking they were protecting the lens, were stunned to learn how much sharper the lens was after they removed the filter (besides, the nice deep lens hood does a great job protecting the lens... as does the len cap when it's not in use). If you have a filter on the lens, first thing I'd do is try some shots without it and see if that solves the problem.

It is also possible that the 100-400mm needs Micro Focus Adjustment fine tuning on your particular camera. It's a pretty simple procedure, described in the user manual (if you don't have the manual, a PDF can be downloaded from the Canon website.... which I'd recommend regardless because with most Canon the printed manuals are abridged, the PDF versions are far larger and more complete). There are also various third party tools that can be used to help with MFA, and even software that can pretty much automate the process (Reiken FoCal, for example).

You can fairly quickly tell if a lens will benefit from MFA simply by looking at your images taken with it. If they appear to always be focused a bit closer than or a little bit past the subject you're trying to focus upon, that suggests that calibration using MFA would be helpful. MFA corrects consistent error, but has limited amount of range to do those corrections. It's possible that a lens is simply out of calibration to the point that it's too much for MFA to correct.That might be due to damage or due to mis-adjustment or due to wear and tear... making the lens unable to focus accurately. Those things would require the lens be serviced professionally (not sure if Canon still works on it, but there are likely independent shops that do).

Another thing... Are you using the lens on a tripod? The original "push/pull zoom" version of the 100-400mm has the type of Image Stabilization that must be turned off when on a tripod, or in any situation where there's absolutely no movement for the IS to correct (i.e., not just when on a tripod, although that's probably the most likely scenario). A few Canon lenses, including the original 100-400mm (not the Mark II), have a type of IS that "freaks out" when there's no movement to correct. It goes into sort of a feedback loop where it actually creates image "shake" blur with rapid movements. This can be seen happening in the viewfinder... rapid jumping (not slow "drift", which is common with IS of all lenses, but does no harm in most cases). Try shooting without IS and see if that helps, but images that have been effected by this "phenomenon" (that's what Canon calls glitches and gremlins ) will show overall "shake blur", nothing or almost nothing appearing sharp.

If you think that might be the problem, simply try turning off IS. Of course, you'll need to use a fast enough shutter speed to be able to hand hold the lens.... something faster than 1/160 for the 100mm focal length setting to a shutter speed 1/640 or faster at the 400mm setting. (Of course, you may need a higher ISO to allow this... Alternatively, use a tripod or monopod to allow slower shutter speeds.)

In nearly twenty years using a number of Canon lenses, I've had one that had some of the autofocus components "go bad". It would focus fine at closer distances, but not on anything over about 25 feet. That requires a professional repair.

It also can be your particular technique with the camera and lens... Especially how you use AF and your particular skill holding a steady shot. Personally I use Single Point (manual selection) 95% of the time with my Canon cameras. Combined with Back Button Focusing and AI Servo focus mode, this is more work for me, but puts me fully "in charge" of exactly where the camera and lens focus. I get a pretty high percentage of shots acceptably in focus using that, even with faster moving sports/action subjects (especially with the very fast and good tracking AF systems such as the 7D use when they are combined with fast focusing USM lenses). When I'm in practice and shooting familiar subjects, I usually only miss focus on a few shots per session... and I bet most of those misses are my mistakes, not the camera's or lens' fault.

The 7D has a high performance AF system that's pretty sophisticated. It has five or six different "patterns".... Single Point, Expansion Points, Zone, All Points/Auto and Spot Focus. In general, the more AF points that are active, the greater the chance the camera and lens will focus somewhere other than where you want. For example, using a multi-point mode like Zone or All Points to photograph a bird flying past you, the focus is likely to be on the closest wing tip, rather than on the bird's head and body. Weigh that against the difficulty keeping a Single Point right on a rapidly moving subject as it flies past!

It's also easy to mix up Single Point AF (which is fast and very good tracking movement) and the more precise Spot Focus AF (which is not quite as fast or as good tracking). Spot Focus (not to be confused with Spot Metering) uses a single, AF point that's smaller than usual for higher precision. I've seen people use it successfully with butterflies... but I generally think of it for stationary or slower moving subjects and stick with the standard Single Point when shooting faster action.

FYI, the 7D has dual processors to support it's fast frame rate, as well as separate chip running the AF system. This is the same setup Canon has used in their top-of-the line 1D-series cameras for the most advanced, high performance AF. No other Canon DSLRs have this (the 5Ds and 5Ds-R have dual processors to handle their 50MP images, but not a separate AF chip). The 7D-series cameras also use the 1D-series' shutter release mechanism for long term durability and to reduce "shutter lag".

Finally, it sounds as if you've have the camera for a while. Have you cleaned the sensor lately? A dirty sensor reduces resolution and can even cause some blurring in images. I know the sensor is "self cleaning", but that can only do so much. After ten years, if the sensor has never been given a "wet cleaning", it likely needs it. This may not be the problem in your case, since you say that images shot with your 24-70mm lens are fine. When it comes to resolution and sharpness, I'd expect a dirty sensor to effect all images made with the camera, regardless of lens. Note: a wide angle lens and small aperture setting would show individual specks on the sensor more obviously... but that's not what I'm referring to. This is more of an overall loss of image quality, due to dust, oils, etc. on a sensor (actually on the protective filter that sits right in front of the image sensor).

Hope this helps! But if it doesn't, post some examples of "bad" images here and maybe we can tell more from looking at them. Be sure to "store original" so we can see an enlarged view and don't strip off the image's EXIF data.

It would seem, that the lowly tripod collar becomes an after thought in the design of these large zooms ! Prime lenses are somewhat better in this regard.

They have to find room for the focusing, zooming and stabilization mechanics....and ergonomicly, this takes up a LARGE area - exactly where the optimum place for where the tripod collar would/should be ! This results in the collar being very close to the camera body and very FAR away from the heaviest part of the lens - the front - which then acts like a huge lever against the collar. Add to this, the small size of the collar and "light weight" materials and you can see why even when bolted down to a good support there can still be considerable movement of the front glass. This becomes more of an issue when your shutter speeds start dropping (lower light) on stationary subjects. Ultra fast speeds on moving subjects will be less noticeable of course.

I noticed this especially using the Tamron G2 with the 1.4X

This is a long lens stabilizer that is used to "help" the collar stabilize the entire lens to the support.
https://www.ebay.com/itm/L200-Telephoto-Lens-Support-w-Moveable-Quick-Release-Plate-Camera-Bracket-Holder/362588202614?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l9372
I use one of these on my 300 2.8 with extenders.

RRS and others make similar (more costly) versions.
.

RRS,

I find your comments most arrogant, and certainly not supportable. Unless you have won first place in every competition you have entered (you haven't), and unless your photography is world famous (it isn't), then you should tone the outward expression of your opinion down a bit.

Photography is inherently subjective, and no photographer should ever assume that his own subjectivity is the standard by which all others are judged.

In county fairs, the "quality" of the judging is highly variable. In many cases, the judges opt for photos the average non-photographer would like. Nitpicking subtle differences in sharpness, etc. are almost always secondary.

I have won Gold awards in Photographic Society of America International competitions, yet my first attempts at entering competitions such as county fairs was frustrating. It was hard for me to realize that the judges were not using my standards (or the standards most of us in this forum would appreciate). Once I realized that, I was able to win such contests with photos you would probably dislike.

Thank you for not directing your post at me although that is exactly what you did. No problem here though. My comment was meant to be a good natured rib at Canon owners though I have owned several Canons, Rolleiflex TLR, Mamiya TLR, Hasselblad(s), several Leicas (both rangefinder and SLR), three 4X5’s, and numerous Nikons and some miscellaneous not so well known cameras. Like you I enjoyed each camera and have never had a problem with any camera. All were splendid performers when I did my part.

A pleasure hearing from you.

Dennis

I used both brands for decades. They are both great camera/lens lines. They ARE different, each slightly better-suited to a different group of tasks. I liked Nikons for dynamic range and Canons for skin tones. Now I use Panasonic Lumix cameras for their balance of filmmaking and stills capabilities. And I don't miss Canikon. But when/if I need one again, I'll rent or buy it.

In the end, our knowledge, experience, training, skills, personal vision, and points of view are far more important to photographic outcomes than the gear we use. We need gear sufficient to support that set of tools, but only other photographers care what each of us uses when they look at our work. John Q. Public non-photographers just appreciate good photos, regardless of what made them.

Mac or PC? Not the point. Ford vs Chevy? No point there, either. What we *do* with them matters more than the brands we use. Think about that the next time you see someone wearing a logo jersey or a fashion accessory with some designer's name on it.