Macro lens for Canon EOS-20D

Hi,

 

I have a 20D and am interested in getting a macro lens. Seeing

conflicting advice when I research it. Seems to be 3 options from

Canon, the 60mm EF-S, the 100mm and 180mm. I don't want to go the

EF-S route (again) since the investment won't work with another camera

body. Some sites say the 100mm doesn't have a true USM motor while

Canon's literature leads one to believe it does. Many people suggest

that 180mm might be a bit long for a macro, particlarly on the 20D

since it has a 1.6 factor for sensor size.

 

Any suggestions? I guess I don't have to stick with Canon but the

choices are already confusing enough without adding other brands.

The Canon 100 f/2.8 MACRO USM, which I own, *does* have USM.

 

As for the focal lenght, that's a personal choice and dependent upon your desired working distance.

The biggest difference will be working distance. The longer the lens, the more working distance you'll have. If you ignore the 60, you only need to consider the price diff between the 100 and 180 - you'll be splitting hairs with quality differences between those two for a general user. And there are two versions of the 100, the older which is non-USM. They do not make the non-USM now but you could get one used. Either 100 would probably be one of the best lenses you'll ever buy.

I would get the 100mm macro but it does depend on your subject.

 

The 60mm is ligher and doubles as a portrait lens. The 100mm is a bit long for a portrait lens on a 20D but gives you more working room.

 

You will be able to use the 180mm very effectively even on the 20D. I have a Tamron 90mm macro and do sometimes find myself wishing for more working distance especially with living subjects. The 180mm is going to be very hard to handhold and will take up a lot of bag space.

 

You missed another Canon option. The 50mm compact macro with the life size adaptor.

 

The newer 100mm has ring USM but does not focus very quickly because of the long throw involved in a macro lens. You can use the limiter to speed up focusing but it will not match a non macro ring USM lens. Fine for most applications.

 

You can do very effective macro work with close up lenses and/or extension tubes. These are smaller than a specialist macro lens. The close up lenses add extra optics to your light path but don't cost you light. The extension tubes add to your lenses focal length and efffectively cost you light (f number is focal length / aperture so increasing the focal length means a higher aperture) but don't affect the sharpness of your lens.

The 100/2.8 USM has a true USM motor (the older version wasn't USM), and it is a great lens. Don't forget to buy the extra hood. From most US dealers, the price of the Canon 100/2.8 is quite close to the Tamron 90/2.8. The Canon 180L is a great lens, too; I've used a friend's copy. But, I prefer the cost and size of the 100, plus the 100 is a bit more flexible for my uses (e.g., nice 160mm telephoto lens on my 10D). If insects are your macro interest, however, I'd advise you to consider the longer telephoto macros (including some of the offerings from Sigma and Tamron, due to cost). I don't like looking at or taking insect macros, so the 100/2.8 is a better option for me.

 

 

Finally, as suggested above, the 50/2.5 is a great lens, especially if cost/size are important, you can live without 1:1, and don't need the working distance.

 

--tom<div></div>

Scott, anyone who is seriously interested in macro photography (i.e. anyone who is serious enough to buy a macro lens qualifies) should obtain John Shaw's "Closups In Nature." This 144 page paperbound book, first published in 1987, remains the most practical and useful work on the subject. It may be out of print, but even so you could probably find a copy on eBay or Amazon. Shaw discusses all the issues: macro lenses, extension, supplementary lenses, lens reversal, lens stacking, exposure, lighting, etc. In addition the book is nicely illustrated with many examples from Shaw's work. Incidentally, Alistair's comment that extension changes the focal length of a lens is incorrect. You do lose light when increasing magnification with extension, but not because the focal length of the lens changes. Shaw explains this effect nicely on p. 141. Whatever you decide, welcome to the fascinating world of macro photography!

Ben is right and I am cheating. Sorry. Focal length is a property of the lens and without adding optics it does not change.

 

The point is that the lens brings close objects to focus at a point behind the sensor regardless of how the lens is focused. Adding extenson tubes can bring that point forward so you get closer objects to focus on the sensor. Depending on the lens adding the extension tubes can mean that the point at which parallel rays are focused cannot be brought back to the sensor and you have lost infinity focus (not that important but you have to remove the extension tubes before you go back to regular photography).

 

As you move the lens away from the sensor the same amout of light is spread over a larger area (imagine a flashlight on the wall).

 

The formula I gave, sometimes called the "effective" aperture, is correct (assuming the lens is focused at infinity - otherwise the extension distance should be taken to be the extension provided by the lens + the extension provided by the tube). Taking a 90mm lens and adding 90mm of extension (exactly what my Tamron macro lens does when focused to 1:1 but not what the Canon does) you get 1:1 magnification and the necessity to adjust by 2 stops. The effective f number is twice what it was before.

 

You don't need to worry about any of this since your camera has a through the lens meter. The only thing to bear in mind is that adding extension tubes makes it less likely you will be able to handhold the camera (especially given the small apertures used in macro photography).

Depending on your intended use, USM may not be a necessary feature. For dedicated macro work you'll probably want to be using MF anyway. Also, since your camera body can only use AF up to f5.6, working with tubes/bellows will quickly strip you of the AF option. Therefore, the Canon loses its (arguably) biggest advantage over third party lenses with comparable properties. Having said all that, let me recommend a nice set of Kenko auto extension tubes. The newest ones work with digital hardware, and you'll maintain all electronic coupling between body and lens (including AF when possible.)<div></div>

One more thing: Thomas, I agree that the optical quality of the 50mm Compact macro is very high. However, it has the most ungodly poor manual focus ring I've ever used. It's on par with that little plastic pinky ring that the 50mm 1.8 has. That was the main reason I got rid of mine. Otherwise, I agree it is a very nice lens.

Thanks, all - great advice! And I will try to find that recommended book "Closeups in Nature."

<P> All macro lenses are <a href="http://www.orchideen-kartierung.de/Macro100E.html">optically excellent</a>. However, if I were in the market for a dedicated macro lens, I'd get the Tamron 180/3.5 for it's build and optical quality, for it's long working distance (the longest of <b>all</b> lenses), for it's reasonable price (only 200$ more than the Canon 100/2.8 macro USM), for it's <a href="http://photonotes.org/articles/beginner-faq/lenses.html#rearinternal">IF</a> and for <a href="http://photonotes.org/articles/beginner-faq/lenses.html#compatibilitythirdparty">Tamron's excellent compatibility reputation</a>. </P>

 

<P>HTH.</P>

 

<P> Happy shooting , <br>

Yakim. </P>

I agree with Andrew about the focus ring on the 50/2.5, especially compared to the great ring on the 100/2.8 USM. That said, I like the size and quality of the 50/2.5 too much to complain too loudly. --tom