Macro AF?

[TsPoet]

Trying to read through my 7D manual. I think I've got it set for BIF, but the macro suggestions have me a bit confused.
From the canon website
"A new Intelligent Macro Tracking function helps reduce blur during macro shooting by recognizing when a macro lens is attached and automatically adjusting the AI Servo sampling frequency. This AI Servo adjustment accounts for camera movement forward and back, a typical occurrence when moving in close for a macro shot as photographers rock back and forth, or a flower blows in the wind."

Seems to me a spot focus and probably spot metering would be called for, why servo? I do get the blowing in the wind thing, but at my level I think I might just skip that shot.
What AF and metering settings are recommended for macro (bugs especially)?

[Mike]

A lot of people, myself included, manually focus the lens to the maximum 1:1 focus distance and then leave it there. Then to focus I move myself a few mm forwards or backwards to get the subject in focus.

[TsPoet]

A lot of people, myself included, manually focus the lens to the maximum 1:1 focus distance and then leave it there. Then to focus I move myself a few mm forwards or backwards to get the subject in focus.

Makes sense. So, as a general rule, would the reported closest focusing distance be ~1:1 (on a fully extended zoom, or a prime)?
I think I'm going to buy a book on the topic.

[Mike]

You need a dedicated macro lens for full 1:1 magnification and these are always primes (the zoom lenses that have a "macro" in their title are all liars and none of them are true 1:1 macro lenses).
Closest focusing distance is a little different - that is the minimum working distance between the lens and the subject and is different with each lens you use.

[markol]

Controlling DOF and focus is the most difficult part of macro photography, because depending on the plane and orientation you might be dealing with a razor sharp line of focus. You can compensate for this by moving the camera around and trying different angels but generally people focus manually since the area is so small. AI Servo could theoretically be useful since the area of focus will move in and out (or back and forth) across a plane, but you're better off focusing manually or doing like above and just moving your camera back and forth a mm or two.

[marcoj70]

I always have been shooting macros on manual focus, but recently I tried (by mistake!) using AI Servo, and I found out it does work quite well: whenever I'm in an awkward position where it difficult to stand still, or the insect is constantly moving, is actually easier to let the autofocus follow the subject than adjusting my distance to it. Within certain limits. I still have to experience it, but i think is something worth experimenting for extremely unstable situations

[tintinb]

I too thought spot-metering would be more effective, but am not sure if spot metering and AI-servo can be decoupled in 7D body.

I think the advantage of the AI-servo AF in macro focussing is in framing the shot (how much or how little you want to get) on the fly, while still maintaining focus without manually compensating for the movement back and forth.

Trying to read through my 7D manual. I think I've got it set for BIF, but the macro suggestions have me a bit confused.
From the canon website
"A new Intelligent Macro Tracking function helps reduce blur during macro shooting by recognizing when a macro lens is attached and automatically adjusting the AI Servo sampling frequency. This AI Servo adjustment accounts for camera movement forward and back, a typical occurrence when moving in close for a macro shot as photographers rock back and forth, or a flower blows in the wind."

Seems to me a spot focus and probably spot metering would be called for, why servo? I do get the blowing in the wind thing, but at my level I think I might just skip that shot.
What AF and metering settings are recommended for macro (bugs especially)?

[DQE]

Ideally, I would like to pick out one of the AF sensors ahead of time, place that sensor on a critter's eye, and then permit the AI servo focus to compensate for the bug's motion and my shaky hands while the image of the bug's eye moves around in the viewfinder.

This is more or less how many bird photographers shoot birds in flight, I believe. They plan for where they want the bird's eye to be in the scene and let the AI servo keep the eye in focus while it flies around and while the photographer pans the camera and keeps the bird in the frame somewhere. Then, when the composition seems approximately correct, press the shutter and take photos at the max frame rate until the buffer fills!

Based solely on their ads and news releases, Canon seems to be upgrading their AI servo algorithms, allowing for a variable rate of sampling, etc. It would be interesting if these improvements work reliably for high-magnification macro. Wouldn't help much with the MPE-65, though, since it doesn't have AF. Also, at high mag, the DOF for critically sharp detail is incredibly narrow, much narrower than normal AF adjustments. Perhaps if a special-purpose high-mag lens and camera were designed and built? Or, maybe the 7D is such a camera and the 100 mm L lens is such a lens, at least up to 1x mag?

[pigtailpat]

You need a dedicated macro lens for full 1:1 magnification and these are always primes (the zoom lenses that have a "macro" in their title are all liars and none of them are true 1:1 macro lenses).

This was one of the reasons I decided to get the 100 L macro. I was too afraid of the manual focus only on the MP-65 (true macro 1:1) (despite the almost majority I see of macro shots done here with manual focus). I felt for a newbie it would be too overwhelming trying to get it right, and then the necessity for the twin macro flash - made it very expensive. I wanted the additional focal length and the backup of automatic focus.

However, I shall experiment with manual focus on the 100L. But my question is, when you do not have a live view camera, how can you be absolutely sure you have nailed focus when doing it manually? I'm sorry if this is not proper to post on this thread, but I thought the question is pretty similar to the OP's train of thought (for automatic focus and macro).

Thanks.

[Warl0rd]

The problem I see with AI Servo is that if you get too close (bellow minimum focus distance) then the lens will try to AF in infinity, making you loose the subject for a few moments (until it seeks back and reaches 1:1 again).

If you get away from the subject then AI Servo should do its work :)

But considering most of us want 1:1, getting too close is frequent and AI Servo would ruin it :(

[DQE]

The problem I see with AI Servo is that if you get too close (bellow minimum focus distance) then the lens will try to AF in infinity, making you loose the subject for a few moments (until it seeks back and reaches 1:1 again).

If you get away from the subject then AI Servo should do its work :)

But considering most of us want 1:1, getting too close is frequent and AI Servo would ruin it :(

I agree with this concern, which would be a fatal flaw with respect to my own preferences.

It seems to me that one must be able to dial in a specific magnification before activating the AI Servo focus tracking. If the bug moves outside the desired focus range, it's up to the user to move slightly closer or further away to reacquire the target. AI Servo often requires user intervention, whether it be panning in the case of tracking birds in flight, or moving around in the case of bugs. The additional problem I now realize with respect to bugs is that bugs often move more or less randomly, not in a smooth manner. My hands have the same problem if I am not able to obtain auxiliary support (as with Lord V's beanpole system).

Hmmm...not sure how often AI Servo would be helpful in practice, but perhaps it would be useful if the bug is fairly stable since it would offset most of the loss of focus caused by the instability of my camera.

I don't have nearly so much trouble at 1x mag, and wonder if AI Servo would really work with extension tubes up to about 1.5 or 2x mag. As was mentioned in the cited post, once you move in too close, the AI servo might get lose for several seconds since the new lens doesn't have a switch to restrict the AF seeking to a narrow close-in focus range.

It's too bad the MPE-65 doesn't have any competition - there may not be enough future new sales to motivate Canon to add some sort of very new high-mag focus tracking feature along with high magnification-compatible image stabilization. I guess this means I need to continue developing my skills!

[Warl0rd]

I don't have nearly so much trouble at 1x mag, and wonder if AI Servo would really work with extension tubes up to about 1.5 or 2x mag.I doubt it because with ETs and using MF I have trouble getting AF lock light on. I shoot because I can see the focus is where I want it, but most of the time the viewfinder AF light doesn't lock, probably because its too dark. So AI Servo would probably keep hunting with ETs on.

[marcoj70]

I doubt it because with ETs and using MF I have trouble getting AF lock light on. I shoot because I can see the focus is where I want it, but most of the time the viewfinder AF light doesn't lock, probably because its too dark. So AI Servo would probably keep hunting with ETs on.
As soon as you put ET (ET? lol!) on, autofocus, whenever in Servo or other modes, starts hunting: I think this is not a problem of darkness, but rather the fact that the lenses still transmit distance information to the autofocus system, but can not take in account the tubes; the information transmitted does not match the actual focusing distance (when you have the tubes on and you set the lens to focus at, say, 1 meter according to the scale on the lenses, actual focus is much closer).
I do still see the red light blinking with the tubes on, but very briefly (and not as it does usually when it locks). It still tells me that i reached focus though, so I use it!

[Warl0rd]

I do still see the red light blinking with the tubes on, but very briefly (and not as it does usually when it locks). It still tells me that i reached focus though, so I use it!same here, but not always

[DQE]

same here, but not always

Perhaps an auxiliary focusing light would help the AF find its target at higher magnifications (i.e., with extension tubes). I can get away with this about 70% of the time, as so many critters have a one-track mind while eating, etc. I routinely use a 3-watt, high-intensity, LED flashlight without provoking most critters to flee. It doesn't affect the photos much since the flash is so much brighter, other than sometimes creating a very small extra reflection in spiders' eyes. Perhaps they think it's the sun?! My shadow seems to be more frightening to things like flies.

Just a 2 euro/cent thought...I hope it is of some use.

[Warl0rd]

one of my concerns with led lightning is the extra weight. body+100mm macro+ful set of ETs+bracket+flash already weights a lot (and I ditch the body grip), after a few minutes of hand holding everything I notice I start shaking more and more :(

[DQE]

one of my concerns with led lightning is the extra weight. body+100mm macro+ful set of ETs+bracket+flash already weights a lot (and I ditch the body grip), after a few minutes of hand holding everything I notice I start shaking more and more :(

I think I wasn't clear about the LED focusing assist light that I use. It's just an LED flashlight that uses two rechargeable NiMH AA batteries. I hold the head of this little flashlight in my left hand between a couple of fingers, pressed against the side of the lens barrel, and it can be easily aimed at the subject while looking through the viewfinder. The image in the viewfinder is then very bright and highly detailed, especially helpful at high magnifications. Other people don't seem to need to do this, but my aging eyes benefit greatly from having a bright scene with full fine detail to focus on.

Miraculously, perhaps 70-80 percent of the bugs I photograph don't seem to care at all that a very bright flashlight is shining on them, including most flies. Of course, very skittish bugs that tend to fly or run away if you blink your eyes or move an eyebrow will certainly object to a flashlight beam. Perhaps they think it is the sun??? Some of the same bugs who don't mind a focus assist flashlight do run away if my shadow suddenly covers their body or if I suddenly move the camera a centimeter or two.

I hope this additional info is helpful to some reader. This is surely another of those "your mileage may vary" and "your preferences and needs may influence your experience" topics. To each his/her own, as the saying goes.

[Warl0rd]

you were, the thing is, all my gear already weights a lot, adding 2AA+LED would add extra 100grams at least... but yes, I'm sure I would appreciate the brighter viewfinder.