[lotech]

Hi there I've a question regarding close up/Macro photography. I used an extension tube with regular prime lens to shoot flowers handheld, since the lens is MF type without electronic coupling, the camera will ask the focal length to use, I believe this is for setting proper anti vibration. Since the lens is shooting at closer than normal distance with greater than normal magnification ratio, should I enter a greater focal length no. to compensate the anti vibration, and what about reciprocal shutter speed ?

[photoptimist]

Technically, from the standpoint of the SR system, the correct focal length would be the focal length of the lens plus the length of extension. That distance determines the amount of lateral motion of the image on the sensor for a given angular swing or dip of the camera.

That said, SR is less effective for macro especially for manual lenses and manual extension tubes. Because the camera does not know how close or far you are from the object, it does not know how to correct for up/down or side-to-side bobbles. That is, it can only do a 3-axis correction rather than the full 5-axis one.

Acceptable shutter speeds for macro really depend on the photographer (swaying photographers need faster shutter speeds) and shooting conditions (swaying flowers need faster shutter speeds). Anything you can do to brace yourself (or shield the subject from wind) will help.

The beauty of digital is you can quickly learn what works by checking each image as you take them. Flowers are patient subjects.

Enjoy!

[Not a Number]

I always enter the focal length of the lens. Seems to work.

Experiment and report your findings.

[lotech]

Thanks guys for the tips, so there is no sure answer for this, but practice makes success, and I will shoot at high shutter speed whenever possible.

[UncleVanya]

There are some old threads that explored this. I think I found 2x focal length when at 1:1 which agrees with the info above.

[pentageek]

2x focal length when at 1:1

What about lens which achieve 1:1 without extension tubes, and they are mounted on tubes in order to achieve, say, 2:1? Nevertheless, the question of focal length of macro rig for SR system is very interesting, and I wonder whether forum members have experimented with it.

[Not a Number]

I guess the thing to do is use one of the older AF macros that don't use internal focusing, leave it in AF mode and see what focal length is recorded in the EXIF at 1:1 extension.

[pentageek]

see what focal length is recorded in the EXIF at 1:1 extension.

My F 100/2.8 macro always reports 100mm

[UncleVanya]

What about lens which achieve 1:1 without extension tubes, and they are mounted on tubes in order to achieve, say, 2:1? Nevertheless, the question of focal length of macro rig for SR system is very interesting, and I wonder whether forum members have experimented with it.

I was specifically talking about reproduction ratio not tubes. I used several different methods and still it appeared to me that was a good rule of thumb. I think a macro lens at 1:1 isn't real the normal focal length any more since that is measured at infinity.

[Wheatfield]

Technically, from the standpoint of the SR system, the correct focal length would be the focal length of the lens plus the length of extension. That distance determines the amount of lateral motion of the image on the sensor for a given angular swing or dip of the camera.

This is the correct answer. You probably won't notice much difference no matter what the setting is, as long as it's not way out in left field someplace.