Bird-in-flight lens and exposure compensation question

[MuleShack]

I have a canon 70 or 75-300AF with IS for my zoom lense. My camera is a Rebel XSi. First off, my camera only goes to 1600 for ISO and The lense is a 4.0 max aperature. When i was shooting those duck shots in another post I tried to get the shutter between 250 and 400 to stop the action and consequently I had to have the ISO at 1600 most of the time if I remember correctly. i think I got a couple at 800 when the sun was bright but a little hazy and it needed to be 1600 on the full zoom.

Obvioulsy for clearer/cleaner pictures you want to use a lower ISO correct?

Would there be electronic updates that would be available for the camera and would it help if possible?

Does the 100-400L lense let more light in in the same situations than my 300? Also how fast is it in comparison to my 300 for focus speed?

Lastly I've played a little bit with exposure compensation, and unfortunately it wasn't good. I had changed the setting when we were on vacation in Duluth in September and my shots from that period were over exposed because I forgot to change it back. How would the compensation play into this where I could possible have a lower ISO /higher shutter speed combo?

I normally shoot in either AV or TV mode and change the white balance to match the conditions.

Thanks

Steve

[Steve Foss]

Steve, this is going to be a bit of a long ride, so hold on tight and grab a cup of coffee.

You'll see I changed the title of the thread, but that's only so people using the "search" function in the future will more easily be able to find the information.

When doing birds in flight (BIF), I keep my camera in Av mode, the aperture wide open and use ISO to control shutter speed. Your 1/250 and 1/400 shutter speeds are on the slow side for BIF. I've gotten sharp images at those speeds, but your panning technique has to be very solid and not shaky at all in order to achieve it. SS of 1/1000 is much better. If you are using Tv and setting your shutter speed at, say, 1/400, even on cloudy days you're probably giving away available shutter speed. That's why I stick with Av and wide open aperture. Even with a lens that only opens to f5.6, at ISO1600 you should be getting faster shutter speeds than you are.

Or, if the light is consistent, either full sun or full cloud, I'll switch to manual exposure mode and get things dialed in at wide open aperture using the histogram. Once your settings are good to go in manual, you can keep shooting that way until the light changes. Doesn't work well on a partly cloudy day, obviously.

There's no firmware upgrade I'm aware of that will give your body ISO3200, but are you sure the XSi doesn't go that high using ISO expansion in the custom functions menu? Check your manual on that.

The two lenses you mentioned will focus at about the same speed on that body. The 100-400 may be just a bit faster, but if it is the difference is negligible. Using Ai servo focus mode and the settings already mentioned, I've done a LOT of BIF work with the 100-400 and Canon's 400 f5.6L (most of it with the 20D, 30D and XT, though a good bit with "1" series bodies), and once you get your panning technique down, either zoom will perform well enough for you to get nice sharp images. The extra 100mm reach with the 100-400 can be a key for BIF or nature photography in general. Avian photographers seem to always be searching for more reach. The push-pull zoom design of the 100-400 comes with its own learning curve, but I didn't find it offputting. IQ will be slightly better with the 100-400, but not by very much at all.

If you are seriously considering the 100-400 and would be willing to hold on to the zoom you already have, you might consider instead the 400 f5.6L. It's a non IS, but IS isn't very important when panning BIF shots, and the 400 prime is a little bit sharper than the 100-400. Some will say it's HUGELY sharper, but I haven't found that to be true. Mostly that's just the typical anal-retentive exaggeration you get when you read online photo gear reviews. We photographers are VERY picky people.

Nonetheless, the 400 prime is tack sharp wide open (whereas the 100-400 only achieves its best sharpness stopped down to f8). As a pixel peeping photographer, the difference is noticeable and has an impact in how much cropping you can do and still come out with a sharp print. And the prime is smaller and more compact than the zoom. Not to mention significantly less expensive. Zoom lenses are priceless for their ability to give you instant flexibility in composition, which is why I'd say you could consider holding onto your 70-300 and looking into the 400 prime. The prime also focuses slightly faster than either zoom, and that does have some impact for BIF. All these factors combine to make the 400 f5.6L the most popular affordable BIF lens among Canon shooters.

So, some lens food for thought there.

Also, when using Ai servo, make sure that only your center focus point is enabled rather than letting the camera automatically choose your focus point. The automatic feature slows down focus acquisition and tracking, and the center focus point on that body is more sensitive than any of the others.

Exposure compensation is not used as a tool to lower ISO or increase shutter speed, but rather as a way to override your camera's automatic metering in order to accurately expose your subject. For example, a fairly small dark subject against a bright background will lead your camera to meter for the overall brightness, and your dark subject will be badly underexposed. So you spin the EC dial (or work the buttons) to move exposure to the right (overexposure or +EC), which will overexpose the bright background but properly expose the subject. With a smaller white subject against the dark background, you'll move things to the left (underexpose or -EC) to get a better exposure on the subject.

Underexposing (-EC) yields faster shutter speeds, so if it's a white gull against a dark sky, your using EC to properly expose the gull will help you by producing a faster shutter speed, in many cases allowing you to adjust to a lower, more desirable ISO. However, if you are already at borderline shutter speeds for BIF, and you have to use +EC, you're going to have to raise ISO to compensate for the slower shutter speed that +EC gives you.

Clear as mud?

Much easier to show/explain in person in the field. If it's any consolation, avian photography is IMO the most challenging niche of nature photography, and BIF is the most challenging sub-niche to master within avian. The right techniques must be coupled with solid knowledge of the camera and controls and the ability to make rapid exposure adjustments as conditions change. All while you might only have a couple-three seconds before the bird is in the next county. That demands the most out of the photographer and his/her gear. It's essentially sports photography within the nature field, minus the possibility that a 230-lb linebacker might take out you and your equipment along the sidelines.

Time and practice go a long way, Steve, and it's a lot of fun moving through the journey. Hope that helps you out, and feel free to ask followup questions to clarify.

BTW, love that Favre quote in your signature. Just wish he was saying it about my Packers.

[finnbay]

MS,

This sounds like a lot of stuff. Steve and I talk about this kinda info on our "rides" a lot and the bottom line is getting used to your equipment and what it can do. When an opportunity presents itself, you don't have time to get back to the manual or notes you might have to come up with the right settings. It has to be second nature. How does that happen? Same way you get to Carnegie Hall! Good luck!

Ken

[MuleShack]

You'll see I changed the title of the thread, but that's only so people using the "search" function in the future will more easily be able to find the information.

[OutlawTorn]

Although your keeper rate will climb as you become more proficient with your camera, you will always want to click that shutter as many times as you can when you have an opportunity.

Ive had my 40D for a little over 6 months - it was my first foray into the world of DSLR's. After thousands of clicks and a lot of research on the 'net, Im confident in my abilities to make technically proficient images of still subjects - landscapes, objects, portraits, etc. Artistically, I still have plenty (read: tons) of room to develop.

With action shots on the other hand, like BIF, my keeper rate is much closer to yours. Although I understand Steve's comments fully and apply it to still subjects every day, I cannot process the information fast enough in my head to catch many of those split second opportunities.

[MN Shutterbug]

If you've ever done any bird hunting, the technique is similar. Lock the center focus onto the bird, keeping it locked while shooting and follow through. Be sure to be situated so that you can swivel your hips easily. Unlike bird hunting, you don't lead. It does take a lot of practice to initially lock onto the bird, because many birds don't fly straight. Once you lock on, keep the shutter button pressed and fire off as many as you can. As soon as you release your finger, you've lost focus and by then the bird is too far away or it's presenting it's backside. Actually, shooting with a shotgun is much easier because you can be off aways and still get lucky with a stray BB.