View Full Version : Tubes
michaelb
05-05-2008, 06:48 PM
I've always wanted to pick up a set of extension tubes, but I've been put off by negative comments that I've read about them. Most people make it sound like their only for wedding photogs to take their ring shots!
Not having a macro lens for the 5D yet finally pushed me over the edge and they arrived today. Its a set of Kenko tubes that I ordered off of Ebay from Hong Kong for about $120 shipped.
I only used them for an hour or so tonight, but I must say I'm quite impressed and I wish I had picked up some of these along time ago.
20mm of ext tubes with the 24-105 is like macro with IS!! I also used the 70-200 with a full set of tubes, which is trickier to use.
I'll always keep the 20mm ring in my bag for use with the 24-105 when I don't want to carry a macro lens.
Here's a few from tonight. They aren't great shots as I only had an hour or so to play with them, but I'll definitely be experimenting more with these....(all on the 5D)....
24-105, 20mm tube, 105mm, f/7.1, ISO 200, 1/13, tripod....
http://brownphotography.smugmug.com/photos/290437036_rGyoF-L.jpg
70-200, full set of tubes, 159mm, f/16, 1s, ISO 200, tripod...
http://brownphotography.smugmug.com/photos/290437080_BG2QH-L.jpg
24-105, 20mm tube, 88mm, f/5, 1/30, ISO 400, hand-held, focus on center of leaf...
http://brownphotography.smugmug.com/photos/290437229_RCznE-L.jpg
24-105, 20mm tube, 102mm, f/5, 1/30, ISO 400, hand-held..(focus on pink bud)...
http://brownphotography.smugmug.com/photos/290437081_sXj5H-L.jpg
24-105, 20mm tube, 85mm, f/4, 1/15, ISO 1600, hand-held....
http://brownphotography.smugmug.com/photos/290437035_5Z2er-L.jpg
JMWallace
05-05-2008, 08:01 PM
I have to admit...
I actually looked over my shoulder to make sure my wife wasn't in sight of the monitor before I clicked.
Bummer.:eek::o:p
i;d like to know who the negative comments are from. tubes rock.
TheWengler
05-05-2008, 09:00 PM
Maybe one of you geniuses can help me understand this. I saw somewhere recently that the formula for calculating the magnification of a lens when paired with extension tubes was this:
Magnification = Extension length / Focal length
Is that right? This doesn't factor in the current magnification ratio of the lens being used. So if you put a 25mm extension tube on a 50mm 1:1 macro lens would it reduce the magnification to 1:2? So does it only make sense to use extension tubes with non-macro lenses?
i dont know the formula but putting exten tubes on a macro lens gives you larger than life size results. a full set of tubes on a macro lens significantly increases your magnification. i just dont know how to work out the numbers.
drama
05-05-2008, 11:46 PM
The maths works out like this
Each lens at a given focal length has a fixed magnication, to which you have to add the extension tube length / the focal length
for a 50 mm lens with a magnification of say .5, if you add a extension tube the total magnification becomes .5 + (25/50) = 1
TheWengler
05-06-2008, 12:02 AM
Thanks drama that makes much more sense.
michaelb
05-06-2008, 05:11 AM
i;d like to know who the negative comments are from. tubes rock.
I've always heard people say that tubes were a pain to use and focusing was very difficult with them, etc, etc.
I had no problems with them however; I even used AF with most of these shots in order to obtain initial focus, without a problem. Once focus was achieved, I then switched to MF so the camera wouldn't keep trying to reacquire focus.
The only thing that was a little tricky was using the full set of tubes on the 70-200, only because the set-up was so long that it was a little unsteady. I had to wait for it to stop shaking before I took the shot :D (using MLU as well).
I would admit though that using this set-up to shoot moving subjects like bugs would probably be very difficult, but for the stationary objects that I like to shoot it works like a charm.
I have to admit...
I actually looked over my shoulder to make sure my wife wasn't in sight of the monitor before I clicked.
Bummer.:eek::o:p
Now you sound like me. :D
My wife was commenting last night about all the boxes that have been arriving lately. ;)
adam75south
05-06-2008, 06:13 AM
weird. i was looking at extension tubes just the other day.
don't really have a need for them...except for the occasion ring shot haha.
FLiPMaRC
05-06-2008, 07:45 AM
My wife was commenting last night about all the boxes that have been arriving lately. ;)I had my most recent lens purchase shipped here at work :D No boxes, not questions :p LOL
24Peter
05-06-2008, 08:44 AM
I use those tubes - they work fine, though like any macro set up, shallow DOF and precise focusing issues are to be expected. I almost bought a Canon 100 f2.8 macro but decided to go with the extension tubes instead. I think the only issue with tubes instead of a dedicated macro lens is the loss of light with the tubes, though I remember reading someplace that macro lenses also suffer from that at macro distances?
FLiPMaRC
05-06-2008, 09:18 AM
How about reverse 50mm+100mm macro+25mm ET ... bbbwwaaahahahahahahaaa!!!! :D :D
http://farm3.static.flickr.com/2332/2470006494_e611426b1d.jpg
That's not mine btw :) Here's the user's flickr page: http://www.flickr.com/photos/philippinosaur/
cwphoto
05-06-2008, 10:25 PM
I think the only issue with tubes instead of a dedicated macro lens is the loss of light with the tubes, though I remember reading someplace that macro lenses also suffer from that at macro distances?
Correct. :)
drama
05-06-2008, 11:47 PM
The canon 60 f2.8 unfortunately cant use tubes with AF, cant use my 1.4X TC either
I think the only issue with tubes instead of a dedicated macro lens is the loss of light with the tubes, though I remember reading someplace that macro lenses also suffer from that at macro distances?
i'm yet to experience that problem to any magnitude, if at all, and i've mounted them to the tamron 90mm/ sigma 150mm/ nikkor 105VR macro lens' and non macro on the 300/f4. i also have AF, metering and VR without any dramas.
if there is any light loss, then it must be pretty insignificant cos like i said, i've never noticed it.
TheWengler
05-07-2008, 12:59 AM
What do you guys mean by light loss? Something similar to what happens when you pair a lens with a TC?
yes, light loss in the way you described. also heard issues with vignetting style loss in the corners of the frame. but again, i've not seen it.
michaelb
05-07-2008, 07:03 AM
yes, light loss in the way you described. also heard issues with vignetting style loss in the corners of the frame. but again, i've not seen it.
With the full set of tubes on the 70-200 I noticed the light loss (darker VF), but with 20mm or so of tubes I really didn't notice any light loss or vingetting.
cwphoto
05-07-2008, 06:36 PM
What do you guys mean by light loss? Something similar to what happens when you pair a lens with a TC?
In simple terms, when photographing at reproduction ratios of 1:1 (ie; life-size) there is a light loss of two f-stops.
However, most macro lenses employ a floating optical system, meaning that the effective focal length is reduced as magnification is increased. This results in there being less light lost than would normally be the case.
The Canon 180/3.5 is like this. At 1:1 this lens only loses 1.3 f-stops from memory.
TheWengler
05-07-2008, 09:06 PM
Thanks for explaining guys.
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