I'm thinking of purchasing one of the 18-200 Canon compatible lenses offered by Tamron or Sigma. This would be for use on a digital camera (probably the Canon 400D).

I think Sigma have just introduced a new version of the 18-200 lense with an Optical Stabiliser.

I know that the quality won't be as good as using two or three separate lenses but I'd really like to carry less gear around.

Does anyone have experience of these lenses or advice please?

Lynn,

You will be much happier with the 80-400mm Sigma that also has OS. A bit heavy but you will need the zoom.

I had an extender on my 80-200, and had it on the lens all the time. But you'll loose a lot of light with the extender
It worked for me because my lens is F2.8, and I could affort the loss of light.

So I agree with roccco that you should aim for the 400mm.. (but of course, we don';t know the budget )

I also agree with Rocco that the 80-400 is a far better choice for safari pictures than the 18-200. It is far heavier and probably costs at least twice as much, but 200mm is not enough reach for wildlife.

However, your post said a lens for safari "and general travel." I suspect that if you took only the 80-400, you would encounter some situations where you would want a wider-angle lens to take pictures of landscapes, buildings, or people. Sigma makes a 17-70 lens that would fill this role well. It would mean taking two lenses, but I think that is a necessary evil to give yourself coverage for the variety of situations you may encounter.

Canon does have a 28-300mm L series lens that theoretically could be a one-lens solution that could give you coverage at both ends, but it has the drawbacks of lower image quality than other Canon L lenses, high weight, and a big price tag.

I personally did not mind carrying two lenses -- we use a Canon 400D, and had the EFS17-85 for wide angles and landscapes, and the Canon 100-400L for wildlife. We were very happy with our results with these lenses. The Canon lenses cost more, but the image quality is better, and in my view, if you are going to be serious about taking good pictures, you might as well go ahead and bite the bullet and buy the more expensive lenses. It costs less than buying one, then deciding later you want to upgrade.

One other thing to keep in mind, with both the Sigma lenses that you mentioned and the Canon ones I listed, is that they will suffer under low light conditions. To take good pictures in low light you need to buy faster lenses (like the Canon 70-200 f/2.8, or the Sigma 120-300/2.8), which are bigger, heavier, and VERY expensive.

In the end, I think it is important for you to think hard in advance about what your priorities are in terms of image quality, types of pictures you want to take, as well as your budget and tolerance for carrying gear around. Only when you have all those things in mind can you make a rational decision about lenses.

An excellent site to see user reviews of various lenses is www.fredmiranda.com.

Good luck making your decision. We were making the same ones last October in preparation for our trip, but I was so glad we went to a DSLR, because the pictures are very much worth the effort!

Chris

I'll have a minor decenting opinion from the others. A 18-200 lens is a good all round travel lens. And not a half bad safari lens either. How do I know, because on safari in Sep 2006 I had with me only a Nikon DSLR with the Nikon 18-200 zoom. Here are a few photos from the trip on the Kodak Gallery (I'm reworking most of the photos and moving them to Smugmug, soon I hope. Smugmug presents the photos much nicer than Kodak). Anyway here's about 20 shots at - http://tinyurl.com/2xqo7d
All taken with the 18-200. Now, I do agree that much of the time I could have used a longer than 200mm lens. But the 200mm still works and you can easily crop the photo to make it look like a 300mm lens was used. In fact, for my next safari I am taking a Nikon 70-300 - along with the 18-200. If you forced me to take one, and only one lens, it would be a hard choice but I'd probably go with the 18-200. Now if you're after good bird photos, well, we have to start the story all over!!!
regards - tom
ps - those photos from Kenya, if you'd like a few more examples, here's some from Zambia - http://tinyurl.com/yp854t

One thing I haven't seen mentioned much is that wildlife photos are often taken from game viewers. While IS isn't needed if you have a stable platform, often people are moving in the vehicle and having IS makes a big difference. I was very happy with my 100-400mm and used an extender when I needed more focal length.

I agree that image stabilization is a big bonus for wildlife photography (and lots of other uses too). I have seen my wife get handheld shots with our 100-400 at 400mm and 1/80 sec. Here is an example:
http://www.pbase.com/cwillis/image/73177108

It is important to know, however, what IS will do and what it won't. It won't freeze subject motion, so using it for low-light wildlife photography is no good if you have a moving subject. You will get a sharp picture of the surrounding vegetation or whatever, and a blurred animal. If the animal is sitting still, it works wonders.

IS does add to the cost of a lens, but it is far cheaper than buying f/2.8 glass!

Chris

Tom --
A question in my mind regarding the concept of using the 18-200 and then cropping down would be whether the Sigma and Tamron 18-200's are as optically sharp as the Nikkor one you used. I don't use Nikon gear, but my impression is that the Nikkor 18-200 is optically superior to the Tamron and Sigma versions. If that is in fact the case, the cropping strategy would not be expected to work as well with one of those. Cropping down really puts a lens's sharpness to the ultimate test, and my guess is that the less expensive options won't look as good cropped down as the Nikkor 18-200.

By the way, there is a three-way comparison test between the Sigma, Tamron and Nikkor 18-200's at http://www.cameralabs.com/reviews/Sigma18200mm.

Chris

Chris
I agree with everything you say. (Thanks for the lens review link, I have not seen it). The real question is - what is to be done with the photographs? If only smallish 4x6 or 5x7 prints are to be made then it'll work ok. Even if cropped to 3 meg pixels and printed 8x10, most people would be happy (probably not you or I though ).
Just to repeat it again, so much more depends on the technique and skill and eye of the photographer.
regards - tom

Tom, you are so right about photographer skill. I know my 100-400 lens is capable of producing incredibly sharp pictures, because rarely I will get one where my technique has allowed the lens to perform to its potential. But my inexperience and technique gets me a lot of substandard pictures, even with good-quality glass.

There is a saying that "the sharpest lens/camera is the one in the hands of the most skilled photographer," and I think that is especially true with telephoto photography of wildlife.

I also agree with you that we need to hear from Lynne about the objectives/goals for the lens before any of us can give any realistic advice. Your goal, and mine, may be to get portfolio-grade pictures that we can blow up to 20x30 or submit to a photo contest, but if someone else's goals are different there is no need to go overboard spending thousands of dollars on lenses to produce a 4x6 or 8x10 that won't reveal the limitations in the equipment used.

Chris

thanks for all great information. I have done some safari photography before (using two lenses) and I've just got fed up of carrying the gear and changing lenses, especially if hiking!

I don't mind spending the money on a good lens but I do only need to print 5x7.
Your points about cropping afterwards are interesting, that's what I've been doing recently and it has been working ok with an old, inexpensive lens (80-200).

Cropping. Look at the photo, decide what it is "about". Crop out every thing that distracts from the "about". If you can't crop it out, then clone it out in Photoshop
regards - tom