Choosing between two Canon Macro lenses

[Doctor Andrei]

This forum appears to be a skyrocketer for a beginner. A few days after registration I've already stepped my photo game up a bit. So please help me to choose between (1) Canon EF 100 mm F/2.8 USM macro and (2) Canon EF 50 mm F/2.5 Compact Macro.

Im a dentist and my goal is to make nice macro photos of my restorations. My little 18-55mm lens works pretty well for local purposes, but posting my photos on the web and showing them to future patients requires a Macro lens and a Ring Lite. Those two lenses, I cant choose between them. (2) is definitely cheaper, lighter, has smaller minimal focus distance. But reviews on the Canon site say it's too noisy, too slow to focus, and my Moscow colleagues mostly use (1), plus it has excellent reviews and it seems like no one cares about 100mm focus disctance. So which one should I choose?

My goals in photography (goals in dentistry - already reached some):

http://forum.stom.ru/topic/17407-4-c...ax-est-vopros/

[Rob Douglas]

I would say #1. It is a better lens and you won't have to stick it down a patents throat to get the shot. The 50mm has a 0.23m/0.8 ft. min focus distance whereas the 100mm is 0.31m/1 ft. A difference of 0.8m/0.4 ft. So you can get pretty much twice the magnification at nearly the same working distance or be at a
More comfortable working distance and still get the same results. I've used both and like the build quality of the 100mm better as well.

[revi]

If those are both 'real' macro lenses (i.e. give a 1:1 image on the sensor) I'd go for the 100mm, as it gives a bit more working distance, so you won't be quite as much in the mouth of your patients . The smaller closest focusing distance for the 50mm doesn't mean a thing here: for a 1:1 image, you will need to get to 100 mm distance with a 50mm lens, compared to 200 mm with a 100mm lens).

As for the 50mm being lighter and smaller: both lenses have about the same maximum aperture (F2.8/2.5), so the 100mm will have a larger diameter and thus a lot more glass, and I guess the USM motor adds a bit of weight as well.

If you want to go easy, I'd suggest starting with the ring flash (or a system using 2 small flashes). As far as I know, your 18-55mm kit lens should be good enough for the web and small prints, the way you prepare your images will be more important (i.e. do the resizing to the final size yourself and don't forget to sharpen a bit afterwards).

Another point that might be important for you is colour management: some of the photo's you linked to are clearly of the same person, but colours are quite different between images. That's a whole different kettle of fish, and not dependent on your lens (ring flash might make it easier to get reproducible results though).

Remco

[Doctor Andrei]

If those are both 'real' macro lenses (i.e. give a 1:1 image on the sensor) I'd go for the 100mm, as it gives a bit more working distance, so you won't be quite as much in the mouth of your patients . The smaller closest focusing distance for the 50mm doesn't mean a thing here: for a 1:1 image, you will need to get to 100 mm distance with a 50mm lens, compared to 200 mm with a 100mm lens).

As for the 50mm being lighter and smaller: both lenses have about the same maximum aperture (F2.8/2.5), so the 100mm will have a larger diameter and thus a lot more glass, and I guess the USM motor adds a bit of weight as well.

If you want to go easy, I'd suggest starting with the ring flash (or a system using 2 small flashes). As far as I know, your 18-55mm kit lens should be good enough for the web and small prints, the way you prepare your images will be more important (i.e. do the resizing to the final size yourself and don't forget to sharpen a bit afterwards).

Another point that might be important for you is colour management: some of the photo's you linked to are clearly of the same person, but colours are quite different between images. That's a whole different kettle of fish, and not dependent on your lens (ring flash might make it easier to get reproducible results though).

Remco

I guess the 50mm doesn't do anything good, so is the price and weight its only advantages?
A ring flash is required 100%. Colleagues say I'll need to go with minimum ISO and aperture 22-32 to catch the whole mouth cavity in focus, so that makes a black page without a ring flash.

[Doctor Andrei]

http://forum.stom.ru/topic/17064-avantjurnaja-rabotka/

http://forum.stom.ru/topic/17343-luxury-smile/

[Jim B.]

I have a 100 macro and the MR-14ex ringflash.That combination will work fine for you.It's fairly light and well balanced.

[Harpo]

A question for those making the suggestions… Does the lens choice matter whether its done on a full frame or crop camera?

[Snarkbyte]

A question for those making the suggestions… Does the lens choice matter whether its done on a full frame or crop camera?

Well, it does make a difference, because a full-frame will have a wider field of view than the crop-sensor at the same shooting distance and magnification. The full-frame will get the same magnification at a given distance, so you could simply crop the image for field of view, and get the same results as the crop-sensor would yield. I suppose it's also worth mentioning that a Canon EF-S lens just won't work on a full-frame camera (the Canon EF-S 60mm macro lens is specifically for crop-sensor cameras, though it hasn't been mentioned in this thread). Other than that, no significant difference that I can think of.

[Doctor Andrei]

What's a crop-sensor camera?

[ktuli]

Actually - it makes a huge difference since the 50mm is an EF-S lens, and therefor would not even fit on a full-frame Canon camera. So, that is something to look at Dr. Andrei - what camera are you using?

Regardless, my vote would still be for the 100mm. I have 180, 100, 65, and 35mm macro lenses at home, and I will definitely say that the 100mm is the most versatile. Keep in mind though, that with each different focal length, you will also get a different field of view, and with taking photos of a dental cavity, that very well may be something you're concerned with.

- Bill

[Doctor Andrei]

Actually - it makes a huge difference since the 50mm is an EF-S lens, and therefor would not even fit on a full-frame Canon camera. So, that is something to look at Dr. Andrei - what camera are you using?

Regardless, my vote would still be for the 100mm. I have 180, 100, 65, and 35mm macro lenses at home, and I will definitely say that the 100mm is the most versatile. Keep in mind though, that with each different focal length, you will also get a different field of view, and with taking photos of a dental cavity, that very well may be something you're concerned with.

- Bill

My camera is 550D.
Scrolled thru the catalogues and they say that 60mm, not 50mm is an EF-S lens... Anyway I feel like buying 100mm now. If it gives me enough detail, I could just crop the image later to get one tooth as a separate image if I need to.

[ktuli]

I stand corrected. You are right it is the 60mm that is EF-S (though that too will work on your 550D which does have an APS-C cropped sensor).

It looks like you've made your decision to go with the 100mm, but in case you need more justification...

The 50mm is not - by itself - something I would consider a true macro lens. If you look at the specs on it, it actually only gets 1:2 magnification, and needs the "Canon EF Life Size Converter" to get to 1:1 magnification. I'd assume (since that thing is basically a teleconverter) that you'd also get a loss in light with that, thus making your effective max aperture smaller than the advertised f/2.5. Additionally, with the lens currently running $270, the life size converter running an additional $270 (fancy that... the optional accessory to get it to be a true macro lens costs the same as the lens itself), and the 100mm f/28 USM (non L or IS version) is currently $540... you don't even have to feel guilty about spending more to get the 100mm lens. Unless of course if you convince yourself to get the L version for the better glass and IS feature.

- Bill

[Hero]

If those are both 'real' macro lenses (i.e. give a 1:1 image on the sensor) I'd go for the 100mm, as it gives a bit more working distance, so you won't be quite as much in the mouth of your patients .

In this case I wonder if extra distance is really a pro. Usually when shooting through a peephole (the mouth in this case) you want to be able to get as close as possible to have as much angular freedom as possible. ie you don't want to have to walk around the patient to find the angle you need. Besides, contrary to shooting insects, you don't have to be afraid of your subject flying off when you get too close.

[Glenn NK]

Doctor Andrei:

I'm back.

1) I know that your camera is a "crop" body. It has an APS-C sensor (same size as my 30D).

2) A very quick bit of research reveals that the Canon 50mm f/2.5 macro is almost certainly a discontinued lens. It dates back to 1987 and was replaced by the EFS 60 f/2.8 lens.

3) I know from experience that the 100 mm f/2.8 macro will be much more suitable than either the 50 mm or the 60 mm. I shoot thousands of flower pictures where the flower is about one to two inches (25 to 50 mm) in diameter - about the size of a human mouth.

4) When I shoot the lens cap of my 100 mm lens (diameter = 58 mm), the cap fills the frame when the end of the lens is about 300 mm from the cap. So the end of your camera lens would be about 300 mm from a patient's mouth. Does this seem to be a comfortable distance for you?

5) The new Canon 100 mm macro is "image stabilized". This would greatly improve your "keeper" rate. Neither the 50 nor the 60 mm lenses are image stabilized.

6) I'm not a flash photography person, but I have seen dentists use the ring style flash units.

Glenn

EDIT:

Andrei:

I'm quite certain you will not be able to fill the frame with one tooth with the 100 mm macro lens - it will not focus closely enough. The 50 and the 60 will be worse.

In order to get down to this size (approximately the size of a bumblebee) you will require extension tubes, and this gets messy. I use mine when I must.

To get extreme magnification, this is the solution:

http://www.dpreview.com/products/can...n_65_2p5_macro

It will be awkward because it is a manual focus lens.

[ktuli]

I have the MP-E 65. The focusing distance required is absolutely not something that would work. For 1:1 magnification, you've got a working distance of 4 inches!!! I definitely think that is getting a bit too up close and personal for a patient's comfort. It fluctuates around that distance moving to the 5x magnification, but I can pretty much guarantee it wouldn't work for dental photography.

- Bill

[Glenn NK]

I called my photography shop a few minutes ago to find out what dentist's in this city have been doing.

Typically they use a 100 mm macro lens with the ring-lite flash. They do not use extension tubes.

The problem with using a lens/tube combination that will provide a full frame image of an individual tooth is that there will be virtually zero depth of field.

Glenn

[Harpo]

Interesting thread. Ive been considering the 100mm macro for my wife to go with our T2i. So it would work.

Mentioned here was getting the lens too close to the patients face... how about rigging a contraption that looks like the x-ray machine that swivels out and rotates and is placed at the cheek.... instead of the X-ray, have a camera installed (gimbal mount?) and tethered to a monitor to adjust placement instead of climbing over the patient doing this handheld!

[Glenn NK]

Interesting thread. Ive been considering the 100mm macro for my wife to go with our T2i. So it would work.

Mentioned here was getting the lens too close to the patients face... how about rigging a contraption that looks like the x-ray machine that swivels out and rotates and is placed at the cheek.... instead of the X-ray, have a camera installed (gimbal mount?) and tethered to a monitor to adjust placement instead of climbing over the patient doing this handheld!

Mike:

That would be a very good solution. It also provides a place to put the camera when it's not needed (most of the time).

It wouldn't encroach on the patient's "space" as much as hand-holding. However there could be a considerable price for the adjustable mounting system.

Glenn

[Snarkbyte]

I mentioned earlier that the Canon EF-S 60mm lens won't work with a full-frame body, like the 5D, but then I started thinking and tried a little experiment. Actually, there is a way, but there are some limitations...

Ordinarily, an EF-S lens won't even mount on a full-frame body, but the lens will fit an extension tube, and the tube will mount on a full-frame body. As an experiment, I attached an EF-S 60mm lens to a 25mm extension tube and mounted this on a Canon 5DMkII. It worked, but there are some limitations. Auto-focus doesn't work (no real surprise), and even with manual focus, the maximum focus distance is less than a meter. Even so, if you just want a dedicated macro lens, those limitations probably don't matter too much. The EF-S 6mm is $100 cheaper than the EF 100mm, but unfortunately, the cost of the 25mm extension tube very nearly wipes out the price advantage. Still, the EF-S 60mm is significantly smaller and lighter than the EF 100 (though not as versatile, and without AF).

I know this is probably useless information, but you never can tell, so I thought I would post it, anyway.

[WJT]

Hi Doc, I have the 100mm F 2.8 and am very happy with it. My advice is use a tripod regardless as it will give you depth of field. When you first use one it's surprising how much you loose by getting close. I also agree that you dont want to be too close to your patient. Canon I think have 60mm which is used by forensics which would be worth a look.