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Archive 2007 · Reverse mounting info. Topic Name Change.

LordV
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p.2 #1 · p.2 #1 · Reverse mounting info. Topic Name Change.

Tom Hicks wrote:
Will, if the 105 you are getting is a macro lens then you are going to get 1to1, to get to 2to1 with that same lens you need to put 105mm of extension on it . if you have the standard 105 , to get to 1to1 you will need 105mm of extension, since most kits contain 68mm of extension the most you can get is 1.7 to 1 approx.
.

Tom , in practice he will get 2:1 with 68mm of ext tubes on the 105mmEx mainly due to the focal length shortening considerably at minimum focus. I get about 1.97:1 with 65mm of ext tubes with my 105mm Ex.
Brian V.

Dec 30, 2007 at 01:33 PM

Tom Hicks
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p.2 #2 · p.2 #2 · Reverse mounting info. Topic Name Change.

Thanks Brian , I knew that lens's varied from one to another in exacting power, but didn't think about the shortening effect. Are there any articles on this that members can read ? Good info Thanks .

Dec 30, 2007 at 02:31 PM

LordV
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p.2 #3 · p.2 #3 · Reverse mounting info. Topic Name Change.

Tom Hicks wrote:
Thanks Brian , I knew that lens's varied from one to another in exacting power, but didn't think about the shortening effect. Are there any articles on this that members can read ? Good info Thanks .

Tom I wrote a bit about this in a discussion point on Flickr here
http://www.flickr.com/groups/macro123/discuss/112332/

I gather that the real focal length of a macro lens at minimum focus approximates to the the minimum focus distance divided by 4.

Brian V.

Edited by LordV on Dec 31, 2007 at 11:54 AM GMT

Dec 30, 2007 at 03:38 PM

Will Hayward
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p.2 #4 · p.2 #4 · Reverse mounting info. Topic Name Change.

Brian, so going by your calculations using the "Nikon D50 + Nikkor 105mm + 68mm Ext. Tubes" setup, I would be shooting at nearly 2:1?

Ken Rockwell states that if the Nikon 105mm f/2.8 Micro was used with either a TC-200 or TC-201 teleconverter, it would make this essentially a 210mm f/5.6 macro lens and be capable of 2:1. I would loose the AF, however I'd think most macro shooters are using MF (Right?).

Theoretically, if one were to use a TC-201 teleconverter, then 68mm Ext. Tube set, then a Nikkor 105mm, it would provide almost 4:1 (3.94:1) or have I become confused.

Dec 31, 2007 at 04:08 AM

Dalantech
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p.2 #5 · p.2 #5 · Reverse mounting info. Topic Name Change.

The tubes will give you about 2:1, and then if you add a TC you just multiply the power of the TC to get the mag.

So a macro lens at 1:1 with a 1.5TC becomes a 1.5x lens, and the lens + a 2x TC becomes a 2x lens.

The same lens + tubes will give you about 2:1, then multiply that by the TC. If it's a 1.5x TC then the mag is 3x. If it's a 2x TC then the mag is 4x.

Auto focus, even at half life size, is problematic. I manually focus everything from 1/4 life size and higher.

Dec 31, 2007 at 06:18 AM

LordV
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p.2 #6 · p.2 #6 · Reverse mounting info. Topic Name Change.

Just one addition - you need to put the TC nearest the camera and then the ext tubes for the calculations to be correct

Brian V.

Dec 31, 2007 at 06:52 AM

Jody Melanson
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p.2 #7 · p.2 #7 · Reverse mounting info. Topic Name Change.

http://macrorings.com is where I bought all my stuff. Cheap and reliable, fast delivery!

Thanks for the props Will, here is a cool looking Jumping Spider for you, love the do! (YAY! Jumping Spider

)

http://jmelanson.smugmug.com/photos/180795601-O.jpg

Jan 01, 2008 at 11:54 AM

Will Hayward
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p.2 #8 · p.2 #8 · Reverse mounting info. Topic Name Change.

I could be speaking blasphemy, but do two TC's are once work? Is their multiplication added? ie two 1.5X would be 3x the 1:1.

Jan 03, 2008 at 12:21 AM

LordV
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p.2 #9 · p.2 #9 · Reverse mounting info. Topic Name Change.

Will Hayward wrote:
I could be speaking blasphemy, but do two TC's are once work? Is their multiplication added? ie two 1.5X would be 3x the 1:1.
Yes they will work like that but you will lose some image quality (IQ).
The best idea is to suck it and see if you like the result.

Brian V.

Jan 03, 2008 at 02:20 AM

Will Hayward
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p.2 #10 · p.2 #10 · Reverse mounting info. Topic Name Change.

The question is, what looses more IQ, Kenko ETs or Nikon TCs?

Jan 03, 2008 at 03:07 AM

LordV
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p.2 #11 · p.2 #11 · Reverse mounting info. Topic Name Change.

Will Hayward wrote:
The question is, what looses more IQ, Kenko ETs or Nikon TCs?

Ext tubes do not lose IQ whilst TCs do- it's a trade off of IQ vs working distance. You can also get some excellent results with Raynox add-on dioptres such as the DCR-250.

Brian V.

Jan 03, 2008 at 03:12 AM

Will Hayward
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p.2 #12 · p.2 #12 · Reverse mounting info. Topic Name Change.

Beat me to the follow up reply. I sat here thinking about how Tubes have no glass to degrade quality.

So the TC wonk make any need to work closer, but the tubes would. Hmmm interesting.

There are a lot of routes to increasing the 1:1 ratio aren't there. I certainly wish I had funds to try them all.

Jan 03, 2008 at 03:20 AM

LordV
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p.2 #13 · p.2 #13 · Reverse mounting info. Topic Name Change.

Will Hayward wrote:
Beat me to the follow up reply. I sat here thinking about how Tubes have no glass to degrade quality.

So the TC wonk make any need to work closer, but the tubes would. Hmmm interesting.

There are a lot of routes to increasing the 1:1 ratio aren't there. I certainly wish I had funds to try them all.

-

Exactly correct on the TC vs ext tubes. There is always a trade-off of different methods, the one thing that is constant is the DOF at a given magnification and aperture is exactly the same no matter how you achieve the magnification.
Yes there are a lot of ways of getting higher mags - as Tom has explained in some of the stickies you can get to 3:1 simply by reversing the kit lens onto the camera body set at about 28mm. Part of the fun of macro is trying them out. I actually first got to 3:1 by removing the front lens from an old 28-135mm pentax fit Tamron zoom lens and DIY fitting it to the front of my sigma 105 - turned out the lens was equivalent to a +20 Dioptre

. Reversing a 50mm lens onto the front of a 100mm macro lens will also get you to 3:1

Brian V.

Jan 03, 2008 at 03:29 AM

Will Hayward
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p.2 #14 · p.2 #14 · Reverse mounting info. Topic Name Change.

Is there a formula for knowing the closest focus distance with the addition of Extension tubes?

Jan 03, 2008 at 04:39 AM

Dalantech
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p.2 #15 · p.2 #15 · Reverse mounting info. Topic Name Change.

Will Hayward wrote:
Is there a formula for knowing the closest focus distance with the addition of Extension tubes?

Not sure about the formula, but there is a chart at Bob Atkins. It is a little old, since the data for the 100mm macro is the non USM version.

Jan 03, 2008 at 04:43 AM

john paskey
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p.2 #16 · p.2 #16 · Reverse mounting info. Topic Name Change.

ok i understand putting another lens on lens with stepping rings, how do you mount 1 lens to the camera reversed?

Jan 03, 2008 at 07:22 AM

LordV
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p.2 #17 · p.2 #17 · Reverse mounting info. Topic Name Change.

john paskey wrote:
ok i understand putting another lens on lens with stepping rings, how do you mount 1 lens to the camera reversed?

You need a camera body reversing ring such as this
http://cgi.ebay.co.uk/Canon-EOS-mount-Lens-reversing-ring-for-macro_W0QQitemZ350010207330QQihZ022QQcategoryZ106842QQrdZ1QQssPageNameZWD4VQQcmdZViewItem?_trksid=p1638.m124
You still need to match the thread size to the lens filter thread you want to reverse.

You lose all control of the lens doing this unless you get some very expensive reversing gadgets from novoflex. You have to preset the aperture of the lens before reversing by setting the aperture you want with the lens mounted normally and then remove it with the DOF preview button depressed. It's often easier to use an older manual lens to do this so you can manually set the aperture.

Brian V.

Jan 03, 2008 at 07:34 AM

Will Hayward
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p.2 #18 · p.2 #18 · Reverse mounting info. Topic Name Change.

Brian, Is there a formula for knowing the closest focus distance with the addition of Extension tubes?

Jan 04, 2008 at 02:22 AM

Justin Berman
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p.2 #19 · p.2 #19 · Reverse mounting info. Topic Name Change.

When using a lens as an extension tube, i get great results. I have been, with brian's prior advice, able to reverse mount a Nikon f/1.8D 50mm on my Sigma 150mm macro lens. Having come from using a Tamron 90mm, wow, the learning curve is tougher than i would have thought it would be.

Anyway, my question:
Should my Sigma 150 be set at 1:1 or at infinity focus? I have done some rough tests, but infinity focus does not seem to give the same level of magnification as setting it 1:1 and it seems to cause a bit of additional vignetting.

Thanks all you great people!

Jan 04, 2008 at 10:11 AM

Petecc
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p.2 #20 · p.2 #20 · Reverse mounting info. Topic Name Change.

Jody Melanson wrote:
http://macrorings.com is where I bought all my stuff. Cheap and reliable, fast delivery!

Thanks Jody

Thanks for the info

I just ordered a slew of adapters for my lenses. I can't wait to try this out

Pete

Jan 05, 2008 at 07:59 PM

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