CANNON 100 -400 LENS & Cannon XTi

Good morning.

Does anyone use a 100 - 400 f/4.5 - 5.6 L IS USM lens with an Cannon XTi?

If so how do you like it?
If so due yo use a 1.4 converter?
If so how do you like it & will AF work in the 400 range?

Thank you, I am trying to plan for a future purchase & I am trying to decide between Cannon or Sigma Lens.

With the XTi, a Canon 1.4 converter and the 100-400 will not autofocus. The maximum aperature will effective be at least 6.5, and the camera will turn off autofocus.

The only zoom I have ever used any converter with is the 70-200 f2.8 IS, so I can't directly comment on your lens choice. With the 20D, autofocus is certainly more sluggish and I have missed shots because of that.

As a general rule of thumb, adding a teleconvertor to any zoom lens is not a good idea for preserving image quality.

Dan's right on. I have shot the 100-400 heavily for four years. It is an excellent lens and sharper than the Sigmas you mentioned, but adding a TC will degrade image quality slightly, and in my experience this lens can't afford that.

What are you planning to use it for, Richard?

I have an XTi. I asked for advice when I wanted to upgrade from the 70-300 IS, primarily for shooting birds. The advice that I took was to get a 400 5.6 L. I've been very happy with it.

You give up the zoom with a 400 prime, but you gain autofocus speed.

I can only confirm what others have said. I've used the 100-400 extensively for two years, mostly with the 30D, occasionally with the 5D. It's a great lens and very sharp, but you won't want to use a teleconverter with it because of both loss of image quality and lack of autofocus. I shoot a lot of birds, and autofocus is often critical to get the shot - but it may not be critical for your purposes. Even so, image degradation will still be an issue.

The lack of autofocus is related to the lens, not the camera body, and includes Canon primary lenses as well as zooms. If adding a teleconverter to any lens produces a maximum aperature above 5.6, the lens will not autofocus, with a couple of exceptions. A couple of the very high-dollar Canon pro bodies *will* permit autofocus only with the center point and only under certain conditions - but I've never used those so I can't give any first-hand info.

Hope this helps...

I also use the 100 - 400 f/4.5 - 5.6 L IS USM lens with the Canon 400D/XTi

The combination is great but you may find the Xti a bit light to use with a heavy lens. I would prefer to have the 40D with this lens to get a better balance... but it is a bit expensive to pay around twice the price of the Xti to compensate mainly the lack of weight of the Xti (the technical specifications of the 40D are quite similar to the Xti).

Nothing to say about the lens which I find great at all ranges: very fast autofocus and excellent stabilization system. You need however to realize that 5.6 at 400 mm means that you will either need to work in high ISO and/or use a tripod most of the time. Adding the 1.4 converter means that you will get even less light ! Since I rarely use a tripod when hiking (a monopod only when I have the time to focus), using the converter will mean that you will often have to work at 800 ISO or more if you don't have a sunny day.

I have so far never been happy with the final result when using the extender: I personally never managed to get sharp shots with the converter, others apparently did. I personally prefer to shoot sharper with lower ISO and crop the final picture rather than using the converter. The autofocus issue is also a problem with the extender as explained above,

In summary, I think that the Xti with this lens is a fantastic combination for this price if this is the maximum budget you have foreseen. Forget the extender and use the money for getting the 40D instead.

Good luck!

I concur with Gregoire on the balance issue. I shoot the lens mostly on a 30D w/battery grip, and balance is excellent. I have the XT for one of my backup bodies, and it felt too light with the lens until I got the battery grip for the XT. That helped the balance, but was not why I always get the battery grips. Aside from the convenience of a duplicate set of controls for shooting vertically, the grips extend the ability to shoot longer without changing batteries -- a consideration using IS, which eats batteries faster.

Good evening,

Thanks to all for your responses. Obviously the converter is not a choice.

Steve in your first response you said "but adding a TC will degrade image quality slightly, and in my experience this lens can't afford that" and I am not sure how to take that. Are you saying that you are not happy with it?

Thanks again.

I have used the 100-400 for 5+ years and love the lens. I do take a few extra steps to get images as sharp as possible such as stopping down to f8 or going to f11 if using the 1.4x teleconverter. I currently use the lens with the 1D MarkIIN so I maintain autofocus with the 1.4x but it definitely slows the AF down. Another recommendation is to take advantage of the higher ISO settings such as ISO 400 if you decide to try the lens with a tele. I have included a link to an image of an Eastern Meadowlark I took with the 100-400 & 1.4x @ f11, 1/400sec, ISO400. I think the sharpness is just fine but the conditions were also optimal which is the only time I will attach a tele to the 100-400.

I read somewhere that you can over-ride the no AF + teleconverter thing on the xTI by putting scotch tape over several of the pin connectors on the lens ring or whatever that area on the camera is called. Personally I'd rather get the 400mm prime lens instead for the AF speed and sharpness.

With the 100-400, my go-to ISO is 400 and my aperture f8, as already stated by a couple others. Plenty of shutter speed in most situations, and images shot at full focal length and f8 are a bit sharper than at wide open aperture. While f8 will get you that slight amount of added sharpness, I've sold good numbers of images to 300 dpi glossy mags with that lens shot at f5.6 and 400mm, so it's sharp enough for marketable images. Another way to bump up the sharpness factor just a tad is to back down from 400mm when it's not needed. Even coming down to 350mm will have the same impact on sharpness as stopping down to f8, and there are plenty of times the extra 50mm of reach isn't important.

You can tape three of the pins on the TC to get your non "1" series body to autofocus the 100-400, but it is slow, hunts fairly often, and my reading indicates it wears out the autofocus motor more quickly. Some of the TCs that aren't top-line TCs don't report aperture to the camera, and with those autofocus is maintained. However, there remain the image degradation issues.

From Richard Hahn: "Steve in your first response you said 'but adding a TC will degrade image quality slightly, and in my experience this lens can't afford that' and I am not sure how to take that. Are you saying that you are not happy with it?"

Richard, I am tremendously happy with this lens and the IQ it produces. Between the one I own and others, I've now shot four copies of this lens and all have performed as well as the rest. I've captured about 120,000 images with the 100-400 and about 5,000 with the 400 f5.6L. While the 400 f5.6L is a bit sharper and has slightly faster autofocus (both these slight differences are often overblown when comparing these two fine lenses), I need the fexibility of the zoom for the majority of my shooting, which includes environmental portraits as well as tight portraits of birds and wildlife, and lots of outdoor action portraiture of people, including weddings.

I have shot the 100-400 with top-line Kenko and with Canon 1.4 TCs, and with those I've been satisfied with image quality only occasionally (as Kirk mentioned, when lighting is excellent).

If you plan to pursue tight portraits of birds or focus mostly on birds in flight, I'd pick the 400 prime over the 100-400 because you don't need the zoom much and the advantages of the prime, though slight, are clear. And, of course, IS isn't as important when tracking BIF. It's also a few hundred bucks cheaper, and that makes a difference, too. If flexibility is a key, I'd recommend the zoom. Same old dilemma.

I have learned through using these lenses that excellent attention to woodscraft and camo can often be substituted for 500mm or 600mm. In other words, if you work hard to perfect your stalking/camo, you remove the need for longer focal lengths quite often. There will always be times the extra focal length will come in handy, and sometimes you can't do without it to get the image you want, but the more care I take in the woods, the better 400mm suits my needs. Of course, I'm mainly shooting 1.6x crop cameras. If I shot full frame more often, that would be different. Portability also is an issue. I've shot the 500 and 600, and it's quite a bit more of an operation to use them effectively.

Hope that helps a bit further. Don't mean to start a lens war here, either. Just my experiences and a recommendation or two based on them. Others no doubt have had different and just as valid experiences.

Good evening.

Steve thank you very much for clearing up my confusion about your statement. Also thank you for sharing your opinion on lenes with me. We all have opinions about life and are allowed to express them.

Thank you to everyone else also.

The suggestion of the Canon 400/5.6 is a good one! The 400 prime will be sharper at all apertures than the 100-400 zoom and can usually be found used. Of course you give up the zoom and IS, but I would still take the 400 if I found a good deal on one.

BTW, I used the Canon 300/f4 for a long time with total satisfaction.