Extension Tubes

[Paul_O]

I just recently purchased a 50mm 1.8 and absolutely love the sharpness. On my previous camera (Sony DSCS85 with a Carl Zeiss F2-2.8 lens) I was able to take great closeup pics, what effect would the Canon EF12 and 25 extension tubes have when used with the 50mm 1.8 and what are the minimum focussing distances ? Also, are they something you can leave on all the time or are they unsuitable when taking regular walk around style photos of nature etc. Can they be used with a Zoom, especially the 18-55 EF-S ?

I look forward to any info you can provide

Paul

ps I have the 300D and am interested in closeups of flowers, insects etc

[Scottes]

I don't know about the minimum focus distances, but the 12mm would have quite an effect and the 25 would be almost insane on the 50mm. You'd drop the min - and maximum - focus distances substantially. The tube is so close to the lens length that it will change things substantially.

You'd also get high magnification, and incredibly small depths of field. A 300D does not produce as much DoF as your Sony did because the sensor is much larger.


I threw my 12mm tube on my 50mm f/1.8 on my 20D and took a look at things. Max focus distance was about a foot, minimum was about 5 inches. I achieved approximately 1:1.58 at minimum focus, which would comes out to about 1:1 considering the crop factor of the 300D. I'm afraid to try with the 25mm.

In my opinion this is not a workable option for flowers and definitely not usable for moving insects.


They can be used with zooms, but not with the 18-55 becuase that has an EF-S mount and the tubes just won't attach to that.

[Paul_O]

Scottes,
Thanks for the reply, very informative. If that's the case (which I believe it to be) what do people mainly use them for, are they designed for laboratory work or something ?

[Scottes]

I use them a *lot* but on longer lenses. I think my test shows how limiting they can be on a short lens like the 50mm.

I have a 105mm f/2.8 Macro that does 1.1 on it's own. (Or 1.6:1 considering the crop.) It doesn't *need* tubes, but I could get down to about 2.5:1 if I wanted to do so. But then I have to put up with getting very close to the subject (2-3") and that results in very small DoF. OK for static subjects, useless for live insects.

I use them very frequently on my 100-400 L IS for magnification purposes and they decrease the minimum focus distance. A 36mm tube when at 400mm gives me about 27% magnification. Very handy for the small birds I often shoot. And I often shoot butterflies with this lens, so they also allow me to focus this lens closers - which gives magnification - and they give magnification on their own. Double bonus.

And I have a new lens, a 400mm Prime, which has a minimum focus distance of 11.5' - not very good for the small birds I like to shoot. A 12mm tube would allow me to get within the 8' range that I like for small birds.

[MrKickalot]

what effect would the Canon EF12 and 25 extension tubes have when used with the 50mm 1.8 and what are the minimum focusing distances ?

Tons!!! Check out this picture... I put all 68mm of tubes on my 50mm f1.8 and put the UV filter against the glass. The mosquito is on the other side of the glass. The min. focus is less than 1/2". Unfortunately the glass was dirty but it's still a neat picture:

http://www.fotop.net/allmanphoto/Insects/IMG_5493

Also, are they something you can leave on all the time or are they unsuitable when taking regular walk around style photos of nature etc.

No. There is a very finite distance that the lens will focus with it on.

First off!! Don't but the Canon ones. There is no glass in extension tubes so the expense is not justified. The set that Kenko make is only $129 and Comes with a 12, 20 and 36mm tubes that can be stacked. Personally I find the 50 f1.8 to do rather well with flowers. I put the 12mm tub on with it and have had a lot of luck. Haven't put many pictures of flowers on the web but here are a few examples:

http://www.fotop.net/allmanphoto/Flowers

I put all 68mm of extension tubes on my 75-300 f4.5-5.6 and take pictures of insects!! The spider it my favorite so far!!

http://www.fotop.net/allmanphoto/Insects

Like I tell everyone else, if you think you will like macro then get a set of Kenko's and have fun!!!