[Nick Siebers]

Hello all -

I have heard that it is a good idea to adjust the Shake Reduction setting for extension when shooting macro. For instance, when shooting my 90mm macro lens at 1:2, I should include the 45mm of extension and set the "focal length" for shake reduction to 135mm. All well and good. But, when I use a 2x teleconverter to get to 1:1, what setting should I use then? 180mm? 270? Something in between?

Thanks very much for your input! Nick

[Jewelltrail]

Your best Macro will happen on the tripod. When using the tripod, shut the Shake Reduction off.

[Nick Siebers]

Yes, that is so true. 1:1 macro should almost always be done on a tripod. I was stunned when I finally got one how much my macro attempts improved. Still, if I happen to be hand holding, any ideas?

[Jewelltrail]

My 90mm macro transmits focal length to the body, so I can not select focal length. When I use my 1.4 Tele-converter, that does not transmit to the body. Shake Reduction will always automatically choose 90mm for my macro.

If you are in a position where you are able to select focal length for SR, then take advantage of this. If you are using the 90mm with a 2x, then put 180mm into the SR setting.

[ryan s]

Technically, focal length is focal length regardless of crop factor, etc...so I would think the extension tubes wouldn't need any compensation? The tele would need the extra length inputted.

I'm curious about extension tubes though...would they make any difference? Anyone?

[Jewelltrail]

I would like to know about the extension tubes too.

[Class A]

This topic has already been discussed in this thread.

You may not like the answer, which is that the correct value depends on your distance to the subject.

[newarts]

This topic has already been discussed in this thread.

You may not like the answer, which is that the correct value depends on your distance to the subject.

There is a one-to-one relationship between the distance to the subject and the magnification.

It turns out the focal length that should be entered is

Actual_Focal_Length*(1+magnification)

This is because the length of the optical "lever arm" that moves the image over the sensor due to rotations about the lens is f(1+m).

If your lens/extension tube, etc is too automatic & the camera doesn't ask for a focal length, you can fool the camera by placing a piece of aluminum foil over the electrical contacts when you mount the lens/extension tube (squish the foil between the lens and flange.)

Dave

PS not that this is going to fix all your stability problems for hand-held macros but it will help. At high magnifications, in-out & side-side motions of the camera also have large effects.

[ryan s]

Wow I hate math...

I'm looking at a 90mm 1:2 hand-held macro in 16x20" size on my wall, with the SR set to 85mm as always. Granted, it wasn't as stopped-down as it could have been, but oh well

[Nick Siebers]

Well, I think it is clear - use a darn tripod! :-)

[alohadave]

My 90mm macro transmits focal length to the body, so I can not select focal length. When I use my 1.4 Tele-converter, that does not transmit to the body. Shake Reduction will always automatically choose 90mm for my macro.

If you are in a position where you are able to select focal length for SR, then take advantage of this. If you are using the 90mm with a 2x, then put 180mm into the SR setting.

If you are on a tripod though, it's better to turn off SR, whether you can select the focal length or not.

It works by trying to predict motion that handholding would produce, so if it's on a stable tripod, you wouldn't have those kinds of movements, and the sensor would move and introduce softness.

Now, if you are on a tripod that is not super steady, SR may help a bit, but I don't know if anyone has really tested that.

[ryan s]

Well, I think it is clear - use a darn tripod! :-)

My tripod sucks It's like 10lbs and it's impossible to make micro-adjustments. If I get some of my more expensive items sold soon, I'm getting a new one or maybe a lens...

[Gimbal]

It works by trying to predict motion that handholding would produce, so if it's on a stable tripod, you wouldn't have those kinds of movements, and the sensor would move and introduce softness.

Now, if you are on a tripod that is not super steady, SR may help a bit, but I don't know if anyone has really tested that.

Actually I think it’s the other way around. If you are on a stable tripod, you may use SR without problems, -but then of course you don’t need it.

If you are on a “flexible” tripod and engage SR, there is chance that as soon as the SR-system starts moving, the entire tripod will start to countermove/shake. Which the SR tries to counteract and thus inducing even more shaking, and so on…

[Class A]

If you are on a “flexible” tripod and engage SR, there is chance that as soon as the SR-system starts moving, the entire tripod will start to countermove/shake.

Consider the mass of the moving sensor. You have to relate that to the mass of the other system that is supposedly shaken by the sensor. Do you really think even the camera alone (without being mounted on a tripod, say free floating) would be moved with any meaningful amplitude? I want to see the tripod that gets wobbly because of this.

AFAIK, the SR system doesn't predict motion, it just measures it by angular acceleration sensors. When mounted on a tripod, presumably the noise of that measurement process is higher than any real motion, hence the recommendation to shut SR off. Some people even claim they gain an advantage when handholding at very safe shutter speeds and believe SR turned on would introduce blur rather then prevent it. I think the latter would be a disgrace for the SR engineers, but I can see why shutting it off on a tripod could make sense.

[Gimbal]

Consider the mass of the moving sensor. You have to relate that to the mass of the other system that is supposedly shaken by the sensor. Do you really think even the camera alone (without being mounted on a tripod, say free floating) would be moved with any meaningful amplitude? I want to see the tripod that gets wobbly because of this.

I do think so. Try this. Put on a manual lens, SR on, enter for instance 600mm. Set shutter to 4 seconds. Place the camera on a table and release the shutter (make sure SR engages) let go of camera.

With a little “luck” (it helps to give the camera a little twist when releasing the shutter) the camera starts to vibrate on the table. Go again but hold it firmly against the table and the SR remains silent.

Internal noise should be filtered out, otherwise that would always disturb, not only when on a tripod.