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View Full Version : Lens for reversing on 105 macro?


andrewcollier
20th of June 2008 (Fri), 05:04
I have a 105 Sigma macro lens which is fine for 1-1 but would like to go a little beyond that by fittting a reversed prime lens in front, hopefully through Freecycle.


The Sigma has a filter thread of 58mm and I expect most 50mm f1.8's would have a thread of 55mm (?) If I get offered a thread size 58mm with a focal length of say 35mm or 80mm is that worth getting, or am I better getting a 50mm f1.8 with a 55mm thread and suffering a cropped view?

Any comments appreciated.

LordV
20th of June 2008 (Fri), 05:58
I have a 105 Sigma macro lens which is fine for 1-1 but would like to go a little beyond that by fittting a reversed prime lens in front, hopefully through Freecycle.


The Sigma has a filter thread of 58mm and I expect most 50mm f1.8's would have a thread of 55mm (?) If I get offered a thread size 58mm with a focal length of say 35mm or 80mm is that worth getting, or am I better getting a 50mm f1.8 with a 55mm thread and suffering a cropped view?

Any comments appreciated.

You shouldn't get a cropped view with the 50mm F1.8 - I certainly didn't when using a 50/52mm filter size pentax 50mm lens
Brian V.

John_B
20th of June 2008 (Fri), 09:57
andrewcollier,
It depends on how much magnification you want to achieve. ex. a set of Kenko extension tubes will give you approx 2:1 with your macro lens. ex2. a reversed 50mm will give you approx 3:1 with your macro lens.

If your camera is a 1.6 sensor (I don't know as you don't say what you have) then you probably wont notice any vignetting with using the 50mm reversed, and with small apertures even more so. However if using a FF you probably will see strong vignetting.

SkipD
20th of June 2008 (Fri), 10:00
Any lens that you use in reversed position - especially if you reverse it on the body with an adapter ring (no lens mounted to the body normally) - should be an old manual-aperture lens. Otherwise, you'll have one heck of a problem setting the aperture.

John_B
20th of June 2008 (Fri), 10:16
SkipD,
I have found that using a 50mm reversed on a 100mm macro lens you don't need to set the aperture on the reversed 50 (assuming the 50 aperture is wide open). You can still control DOF with the aperture of the 100mm lens. :)

andrewcollier
21st of June 2008 (Sat), 04:39
Thanks for the advice everyone. I think I need a macro coupling ring rather than a reversing ring,

John_B
21st of June 2008 (Sat), 07:38
andrewcollier,
Yes a macro coupling ring is the ring used to mount the 50mm reversed on your macro lens

If you have the Canon 50mm f/1.8 I believe it takes a 52mm filter, so you would need a 52mm to 58mm coupling ring like this
ex. General Brand 52mm to 58mm Macro Coupler - For Mounting Lenses of 52mm & 58mm Face to Face for $7.95 at B&H <--click to see (http://www.bhphotovideo.com/c/product/102220-REG/General_Brand__52mm_to_58mm_Macro.html)

FlexiPack
21st of June 2008 (Sat), 20:05
I've reversed my 50mm 1.8 II on my old kit lens. DOF is intensely shallow at 1.8. You can set the aperture on the 50mm if you wish - mount the 50mm directly on the camera before attaching anything else. Set the aperture you want, hold the depth of field preview button and unmount the lens (keep the DOF preview button held down until the lens is unmounted). The lens will remain at that aperture and you can then go ahead mounting your other lens and reverse mounting your 50mm on to that.

Be warned though, f8 and below is like looking through a pin hole. I think Liveview (if you've got it) focusing is a must! If you get some extension tubes you could also reverse the 50mm on the end of those. I've done that with acceptable results