Canon 100mm Macro AF or MF

I bought a Canon 100mm Macro this Summer and going to use it UW the first time in two Weeks.

With my 50 mm Macro I'am very lucky with the AF and decided not to buy a focus gear.

What is your experience with the 100mm should I go MF and buy a focus gear or does the AF works well.

Simon

from a complete beginner in dslr:

i just used my 100mm canon for 10 days in lembeh and bunaken and had no issues whatsover with the autofocus using the canon 10d. it's a great lens, you'll love it...

i'll be posting some samples this week end, and some sigma 12-24 WA as well

The AF/MF debate very much comes down to personal preference. I am an AF-er! But others swear by MF for a standard macro lens. I was recently given a lecture in an UW camera shop for not even owning MF gears for my lenses, and told I must miss so many shots. Now while I do miss lots of shots, I think that relying on AF is not the major cause...

MF is more commonly used in super macro.

I recently tried both with the Sigma 105mm and I think auto is easier. The manual focus shots are posted here:

http://wetpixel.com/PNphpBB2-viewtopic-t-6...-monterey.phtml

and the autofocus shots here:

http://wetpixel.com/PNphpBB2-viewtopic-t-6...-monterey.phtml

Magnification is around 1:1 to 1:2

I use AF 95% of the time. When it works, it is much quicker and more acurate than I am at MF. But sometimes AF just refuses to work. THe great thing about FTMF lenses like the 100mm macro is that you dont have to decide between AF amd MF before the dive. When AF isnt working for a particular shot you can easily switch to MF.

I agree with WIlliam - since you can switch start out with auto and see if it works.

I get frustrated sometimes with the 50 in AF when it refuses to lock focus. I often shoot kelp where I want a shallower depth of field (ie, kelp stalk facing away....) and the 50 takes some time to figure out where it wants to lock in AF.

Chris

I use AF 95% of the time.  When it works, it is much quicker and more acurate than I am at MF.  But sometimes AF just refuses to work.  THe great thing about FTMF lenses like the 100mm macro is that you dont have to decide between AF amd MF before the dive.  When AF isnt working for a particular shot you can easily switch to MF.

That's right I had forgotten that the 100mm USM can turn to manual just by using a focus ring vs having to be able to switch the lens to MF. Thanks for the reminder. I only shot it in AF on 1 dive so far but will be putting the focus ring on in the future just in case.

Does anyone know if the Sigma Macro 105mm F2.8 EX DG has an M/A mode like the Nikon DX lenses?

So far the 10.5mm is the only prime lens like this but if the macro lens had such a mode I could use the zoom ring in my Ikelite housing to control focus when I need it on the new sigma macro lenses.

This would allow Nikon users the possibility to switch between MF and AF instantly while using primes.

I've tried this with my zoom lenses 12-24mm and 18-70mm and it works but you have to give up the zoom. Because the focus ring moves in AF on the Nikon 60mm (and probably the 105mm) you have to decide before the dive if you want to use AF or MF in the Ikelite housings. I think having the zoom ring attached to the focus ring on the lens and trying to AF would damage your lens.

So you are saying that Nikon does not have the equivalance of of canon's USM or sigma's HSM? That sucks. Glad I went with canon: I love FTMF.

Thanks for all your tips. I was informed, that my local Dealer won't be able to get the focus gear in time for my trip to Ibiza in two weeks, and ordering from the states (Hello Ryan) doesn't make sense for only a focus gear, so I'll try AF only there.

I didn't thought about FTMF so I probably get the Gear for the next trip in December.

Simon

One note of caution on using a zoom ring and AF for FTMF. Keep in mind the focusing motors probably weren't designed with the extra resistance of the focus ring meshing with a focus control knob or lever. I don't know for sure if it would prematurely burn out the focusing motor, but it's something to think about. Some focus controls, such as the one on the S&S Zoom Port, have a special knob that allows you to disengage the knob from the gear when using AF. This would probably be the ideal way to use FTMF. Keep the knob disengaged until you need MF, then engage it to switch to FTMF.

@tshepherd

That is what I planned. I'm also using a S&S DX30/60 so I have this possibility.

Simon

One note of caution on using a zoom ring and AF for FTMF.  Keep in mind the focusing motors probably weren't designed with the extra resistance of the focus ring meshing with a focus control knob or lever.  I don't know for sure if it would prematurely burn out the focusing motor, but it's something to think about.

That isnt the way that FTMF works. When AF focuses the focus ring does not rotate. You could super glue the Focus ring in place and AF would be unaffected.

Immagine a bike. When you peddel (MF) the gear kicks in and you push the wheel forward, but when you are going down a hill (AF) the gear is disengaged and the wheel can spin as fast as it wants even if the peddels are moving backwards.

So no, you cant burn out a USM moter by having resistance on the focus ring. Having a focus ring on does not effect anything since the focus ring does not rotate when the lens is in AF.

You're right William, I didn't even think about the fact that the focus ring doesn't move when AF is used.

I hate it when I post things without thinking them all the way through. Wait, I'll blame it on the lack of caffeine in my system when I posted it!!

It is certainly a great option on this lens. At the time my other option was the Sigma version. Does it allow for the same FTMF?

All I know is the focus ring will be going on all the time now, just in-case.

Sigma version. Does it allow for the same FTMF?

That isnt the way that FTMF works. When AF focuses the focus ring does not rotate. You could super glue the Focus ring in place and AF would be unaffected.  

This was my origional question. Nikon has the same thing on their DX lenses it's called M/A mode. I believe the 60mm and 105mm don't have an M/A mode. What about the nw Sigma digital Macro lenses the Sigma Macro 105mm F2.8 EX DG ? Do they have the equivent of M/A or FTMF? What does Sigma call this system?

It would be great to do this. My Ikelite housing can't disengage the focus ring with the zoom ring (and you need to switch AF on the lens as well as on the camera anyway (!!!Frustrating).

I agree that if you are using the lens without attachments to increase the magnification, AF does a good job. A bright spotting light helps a lot, as AF uses difference in contrast to lock the focus so you can trigger the shutter. this can save battery power as it reduces the time the lens searches for focus

Chris

Back to the original question...

I just got back from a research trip on which I had several chances to use my new Canon 100mm USM lens. It's an amazing lens.

Before the trip I'd posted a similar question about zoom macro in general: do you prefer AF or MF? I got a few answers with varied opinions. Now I suspect the opinions varied because the folks responded were shooting very different sorts of subjects.

Here's what I think now having taken a few hundred shots with this lens:

MF is close to useless if you want to shoot things that are very active, like small damselfish. With the incredibly shallow depth of field inherent to zoom macro, you just can't turn the focus knob fast enough to keep up with the subject. AF does an excellent job for this unless you're shooting something with low contrast (e.g., an all black fish) and here it fails miserably. Consequently, it's helpful to have the ability to switch to MF when necessary (but if your subject is small, black, and moving fast, you might as well just give up and find something else to shoot). Provided you're shooting well lit subject with good contrast, I can't imagine why you'd want to use MF.

The humble opinion of someone who's only owned an SLR of any type for 4 months.

Mark

There is another way of having AF and MF( albeit somwhat modified) on the same dive even if you dont have a focus ring for your lens. Now this works for me on my Canon 10D and I assume it is on the Rebel and other Canon DSLRs as well but I cant be sure.

On the 10D custom function 4 lets you assign different functions to the shutter and AV ( *) button. If you select #1 option, you assign AE lock to the shutter and AF to the * button. With this setup you can press the * button to focus on any subject ( eg. your finger) that is at the desired distanc of your intended target. The focus is now locked and you can move the camera in or out to acheive sharp focus and then simply take the shot without any further hunting of the lens. The fact that AE is assigned to the shutter is not a problem if you are shooting in manual exposure mode.

I have been using the custom function 4 approach for many years with one of my Canon film bodies (Elan IIe) in an ikelite housing and it is a viable alternative if you do not have an FTMF lens as the lens does not refocus everytime you take a shot. BUT the best option by far is to use this feature with an FTMF lens like the Canon 100 macro. This is why I waited for a 10D housing from ikelite rather than going with a digital rebel (lacks custom functions). This configuration with an FTMF lens allows you to autofocus with your right thumb, if you want, hit the shutter without refocusing and use your left hand to manual focus (rotate the ike manual focus port so that the focus knob sticks down and to the left when viewed from the back of the housing). I would argue that this set-up can't be beat for macro. I was so convinced of this that as soon as this lens came out I took a dremel tool to one of old ike manual ports (for my film housing) to modify it to fit this lens (the new standard port is much nicer, of course).

Mike in Miami (waiting out hurricane Frances)