Keith,

There is no one setting that will work in all conditions. Eventually, you simply have to check your exposure via the histogram and the “blinkies” on the LCD. This is especially true when working in full sun, as I know many bird photographers prefer. In full sun, contrast can change wildly as a moving bird exposes different colors to direct rays or moves in and out of shadows. Despite digital cameras’ wide dynamic range, compared to the good old days of slide film, for example, they just can’t hold details over the possible range of dark or black feathers in shade and white ones in sun in one exposure; something has got to give and, for preference, it normally is the dark tones. Burnt-out whites are usually more of a problem than deep blacks in images, the one exception that comes to mind is specular highlights.

Here’s what I do for a general, starting point when working in full sun with a Canon 7dII, EF600LIS(II), 1.4 and 2x extenders, which give effective focal lengths of 960, 1344 and 1920mm, respectively: Auto ISO set to 100 to 1600 maximum; Shutter Speed 1/1000; Aperture f/8 or f/11 (with the 2x); Spot Metering, exposure compensation set to ZERO; Single Point AF (but NOT the smallest point per Canon CPS service); Manual or AV Mode; Image Stabilization ON, Mode 1.

Normally, I make exposure adjustments by changing Shutter Speed first and only change Aperture when I’m out of Shutter Speed range; ISO is picked by the camera’s program within the set range and will top or bottom out before I have to make changes manually, so that gives a moderately wide range where I don’t have to do any compensation.

Whenever possible, I pre-check exposure by doing a test frame, looking for blinkies and the histogram. When exposure is not predictable, a bird with both black and white feathers, like a Black-necked Stilt, turning in the sun and moving in and out of shadows, I simply take my eye away from the viewfinder briefly and glance at the frame image on the LCD, losing as little time as possible from working the bird and making any obvious corrections before continuing.

When a subject is suitably still, I prefer to use manual focus via magnified LiveView or with a magnifying adaptor on the viewfinder – AF can be slightly off or fooled by heat waves, even when correctly adjusted for microfocus.

Four normal gloomy Oregon weather, however, I use a basic setting that works and seldom needs much adjustment. Most of the above settings are the same, only the Shutter Speed is reduced to 1/500 and exposure compensation is set to +1&1/3 (ETTR). I have had to use shutter speeds as low as 1/25 and gotten acceptable sharpness without an extender, but, needless to say, contrast was very flat!

I went birding on Saturday with my 150-600, and in general it worked pretty well, other than it is hard to get very close when you are with a group of 20 people!

The best 'hit' was a summer tanager.

So generally the birds were backlight against the sky, and tended to be under exposed. I also shot a heron flying close to the water with a nice reflection, but the white heron was over exposed.

Do you generally just set a -1 or so compensation when birding and hope for the best. It is hard enough worrying about focus and framing, but to add exposure on top of that...

Sorry for the delay, No my lens does not have IS.  While  IS is a nice feature, it adds complexity and cost.
And while I wouldn't want to be without it on long lenses, it is less necessary on really short lenses.
If you are on a budget, the 17-40 is the best lens for the dollar in the superwide category.
I tend to use zooms as dual focal length lenses. Probably 90+% of the pictures I take with it are EITHER 17 or 40
I know what 17 looks like and I know what 40 looks like. I see the pictures with the camera at my side. As I'm raising the camera to my eye I can flip to 17 or 40 without looking.
Additionally, the diagonal (and thus 'normal FL) of FF is 43mm. So at 40mm the lens has a normal look.  At 17 the horizontal coverage exceeds 90 degrees. You can stand in a corner and get a whole room.
I absolutely appreciate being on a budget, but remember it is the lens that draws the picture, you want the best you can afford.
I love the lens. I may have gotten a better than average copy, but I recommend it highly.
I hope that helps.
M

Sorry, I forgot about the Canon EF 16-35mm f/4.0L IS USM . I guess that effectively is the IS version of the 17-40/4L, but with a slightly different zoom range. It's still out of your price range though at $1100 (which is 38% more than the 17-40/4L). There is currently a $100 mail-in rebate, but that still makes it a $1000 lens.

I've been struggling with erratic focus and image sharpness with my 600/4 and the 1.4 and 2x extenders mostly because I'm an old fart and learned photography in the pre-computer age when photographers were made of iron and so were cameras (figuratively speaking).

An F1 coupled with an FD600/4.5 didn't care how you put the extenders on, so why should these new gimcrack computer thingies care? They're supposed to be smarter than ol' dumb-ass hardware, right?

Actually, no. They are only smarter in a stupider way, in that the complexity of doing one job well makes them vulnerable to how you do your job and attaching teleconverters is a prime example.

In order to avoid confusing the now very sophisticated software, you MUST put the teleconverter on the lens before you attach the camera so that it's tiny brain records the system as a whole. And it doesn't matter if the camera is on or off, you still have to feed it the pablum with the right spoon - lens/converter THEN camera. Likewise  in reverse, perhaps, when removing the converter, although I haven't tested that, yet.

I'm not sure where the little darlings are going wrong, perhaps it is in confusing the microfocus adjustment, but I rather doubt that since when it gets screwed-up, it is plain that there is no plane of truly sharp focus in the images, everything is soft and microfocus should not throw the lens that far out of whack.

If it were up to me, since the telextenders are only intended for the big prime lenses, the manuals for those lenses would all have a warning on the top of the first page in big letters as well as everywhere in the text that refers to the extenders, focus, microfocus adjustment, AF and anything else remotely relevant, not just a routine reference on page 139 or somewhere, as if it wasn't all that critical. And it would include a full explanation of why it is so (I hate authoritarian "Thou shall nots").

I'm not aware of an IS version of the EF 17-40 (but see next post, below). No doubt if they bring out a MkII version with IS, the price will go up by about 50%, so be careful what you wish for!

The  Tamron SP 15-30MM F/2.8 DI VC USD is the only f2.8 EF compatible superwide zoom for full frame that has IS that I can think of. If you wanted APS-C, then there's the Canon EF-S 10-18mm f/4.5-5.6 IS STM, which at $249 is quite a bargain and is the equivalent of a 16-29mm in full frame terms. It's rather slow though.

 

Thanks. Does yourr 17-40 lens have IS ? Probably not but it seems that IS has recently been introduced in the 17-40. I may be wrong.

For what it's worth, I own a lot of Canon lenses and the 17-40 is one of my favorites. I don't know if I got a particularly good copy of the lens but my results are frankly amazing from a picture quality / price standpoint.     I also own the 17mm T/S f/4  which is a world class lens, and for most things I pick up the 17-40.  Good luck

Thanks for the comprehensive survey. I think the best option for me would be to increase my budget. I may have to wait a little but perhaps it will be worth it. 

The Canon 17-40/4L is around $800, so I assume you're looking for something significantly cheaper.

That does seriously restrict your choices, especially since you're looking for something with full frame coverage, not just APS-C. Sigma don't have a full frame (DG) series lens with that type of zoom range that's any less expensive and Tamron don't have anything in their Di (full frame) lineup either.

Your only real option would be the Tokina 17-35mm F/4 AT-X Pro FX at around $450. I think the Canon 17-40 is sharper, and it gives a little more zoom range, plus it has faster focusing. The Tokina may have lower vignetting and distortion, but both of those can be corrected in software anyway.

[UPDATE] - I forgot about the Canon EF 16-35mm f/4.0L IS USM. It's still out of your price range at $1100 (currently with a $100 mail in rebate to make the final cost $1000), but it is another alternative.

Persoanlly I'd go for the Canon 17-40/4L if I could afford it. The Tokina 17-35mm F/4 AT-X Pro FX is $350 cheaper though, so if that's a deal breaker, it's not a bad lens and probably the best you can do if ~$500 is your absolute limit.

As for new lenses, yes, there are some in this range but they are either for APS-C format only or they are more expensive than the Canon 17-40. The new Tamron SP 15-30MM F/2.8 DI VC USD looks very nice, but it's $1200.