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View Full Version : macro lenses + extension tubes = working distance? and hand holding


dia-lt
27th of August 2008 (Wed), 08:08
Hi,

I searched, and searched, and cannot find a clear answer :confused:

Can someone having these lenses and a set of extension tubes (12mm, 20mm,36mm) check this and write down the numbers in cm?

what is the working distance in each case (at maximum magnification)?:

Canon EF-S 60mm ------- 9cm
Canon EF-S 60mm + 12mm tube ------- ?
Canon EF-S 60mm + 36mm tube ------- ?
Canon EF-S 60mm + full set of tubes ------- ?

Tamron 90mm ---------------- 9.9cm
Tamron 90mm + 12mm tube ----------------?
Tamron 90mm + 36mm tube --------------?
Tamron 90mm + full set of tubes -------------?

Sigma 105 mm ------------- 12.2cm
Sigma 105 mm + 12mm tube ----------------?
Sigma 105 mm + 36mm tube --------------?
Sigma 105 mm + full set of tubes -------------?


Canon EF 100mm -------------- 15cm
Canon EF 100mm + 12mm tube --------------
Canon EF 100mm + 36mm tube --------------
Canon EF 100mm + full set of tubes -------


Another question:
Do extension tubes make hand holding significantly more difficult? (will be using 450D)

Mike
27th of August 2008 (Wed), 08:12
Golly, this looks like homework! ;)

dia-lt
27th of August 2008 (Wed), 08:13
Golly, this looks like homework! ;)

I'd be really grateful if someone could do it :oops:

Mike
27th of August 2008 (Wed), 08:19
I don't know the answers but I do know that the working distance shortens quite a bit when you use tubes.

I use an old pentax 50mm lens on a set of cheapo tubes handheld and have had some good successes with it: http://photography-on-the.net/forum/showthread.php?t=475517&highlight=mallorcan+macros

dia-lt
27th of August 2008 (Wed), 08:32
I do know that the working distance shortens quite a bit when you use tubes.


Right, I use 50mm 1/8 II with Kenko tubes, and the working distance is reduced dramatically

Just measured (if anyone is interested):

50mm 1/8 II ------------------------------ 33cm (?)
50mm 1/8 II +36mm tube --------------- 7,5cm
50mm 1/8 II +36mm +20mm tubes ---- 5,5cm
50mm 1/8 II +full set ---------------------4,5cm

I usually use 36mm+20mm, handholding is difficult, but possible.

dia-lt
28th of August 2008 (Thu), 03:58
Anyone? :)

Almost every time someone asks a question about macro lens choice, most answers are "go for more working distance". But sooner or later most people want more magnification, so extension tubes seem to be the most popular first step.

I'm mainly interested to see how does the WD of these macro lenses compare with extension tubes on. Do longer lenses still offer much more working distance, or do they become more or less the same with the tubes?

John_B
28th of August 2008 (Thu), 06:30
dia-lt,
You do loose some working distance, and the smaller the focal length the less working distance to start with.

Canon 100mm f/2.8 at 1:1 focus the subject is 6 inches (152.4mm) from glass.
Canon 100mm f/2.8 at 2:1 focus with a full set of Kenko extension tubes the subject is 5 inches (127mm) from glass.

Hand held photos are very possible as long as a flash is being used ;)

dia-lt
28th of August 2008 (Thu), 08:49
So.. with full set of Kenko tubes on Canon 100mm you lose only 16 percent of the WD (roughly), not too bad at all. I expected a worse result (esp. considering that on my 50mm 1/8 with full set of tubes there's about 86 percent WD loss). Interesting.
Wonder how other lenses compare.