extension tubes

yooperdooper

I plan on shooting flowers and incects this summer.Extension tubes were recommended to me.For lenses I have a Cannon 1:3.5-4.5 10-22mm,A Cannon 3/5-5/6 18-200 mm and a sigma 1:3.5-5.6 18-50mm.The person at the store said I would be better off buying a macro lens for $490.Any recomendations? I have a Cannon eos 30d. thank you

pathfinder

Macro shooting has been discussed extensively here over the last several years.

A quick search for "pathfinder macro lenses" spit out these threads among others. Enjoy.



http://www.dgrin.com/showthread.php?t=25164

http://www.dgrin.com/showpost.php?p=357620&postcount=7

http://www.dgrin.com/showpost.php?p=410825&postcount=10

Specifically about extension tubes, which for me are in addition to a macro lens, not a replacement for one.

http://www.dgrin.com/showthread.php?t=16632&highlight=macro+Greaper

There is a thread specifically about extension tubes here --> http://www.dgrin.com/showthread.php?t=45746

Tim Kamppinen

I have a set of extension tubes that I got for $15. The work well within certain limitations. The good part is that there is no additional glass between the lens and the sensor so the optical quality is very good. The things to be aware of are:

1. Depending on how long the tube is, you will be able to focus extremely close to the front element... 1:1 reproduction is easily attainable. My tubes are stackable so I can vary the length. The problem is that when using the tubes you will no longer be able to focus the lens farther than about a few feet away, maybe only a few inches with the longer tubes. You have a very narrow range of focusing options available to you. This is usually not a problem as you'll be doing strictly macro work most of the time if you need the tubes and not switching between macro and normal shooting. Just something to be aware of.

2. The depth of field becomes razor thin at the close working distances, but as far as I know this is true when using a normal macro lens at very close distances as well. I don't know if there's really a difference.

3. The most important thing to note is that they will not work with all lenses (this is coming from my experience with Nikon lenses but I'm guessing it's the same with canon). They only are useful if your lens has an aperture ring. Many new Nikon lenses and I'm guessing canon lenses as well do not have this, and aperture is controlled strictly by the camera. What this means is that when you take the lens off of the camera the aperture is no longer adjustable and on the lenses that I have used it automatically stops down to the smallest aperture available. So you could use it with the tube but you'd be stuck at f-22 or whatever with no adjustability. A lot of times you want to use the smallest aperture possible to maximize the extremely narrow depth of field, so this might work out ok, except that when your lens is stopped down that far you probably won't be able to see much in the viewfinder and will have huge problems focusing, if you can see anything at all. Again, if your lens has an external aperture ring that you can set this isn't a problem because you can adjust it yourself. You'd probably want to focus at your largest aperture and then manually switch to whatever aperture you desired for the shot before hitting the shutter. Obviously you'd need a tripod to do it like this.

I haven't done much macro work, so I didn't want to spend the money for an actual macro lens, but for $15 to try it out I couldn't resist. It works great with my nikon 50mm 1.8 and I've got some cool shots. That lens has an aperture ring, so it works pretty well. Of course, with that lens I need to get really close to the subject to get a 1:1 reproduction, which means it wouldn't work for some things, like insects or anything where you need to be back a bit. It's the only lens that I own that has an aperture ring, however, so I haven't been able to try the tubes with a longer lens.

Hope this helps!

BTW, what part of the U.P. are you from? I'm from Bruce Crossing... went to Michigan Tech, and now I'm teaching at Ewen-Trout Creek (where I went to school). Nice to see another yooper around.

Tim Kamppinen

I should also add that, Canon or Nikon, the 50mm 1.8 lenses are a huge value at $130 or less, and you should probably get one regardless of whatever else you do. Toss in some $15 extension tubes and you have both a great fast, sharp lens as well as a way to experiment with macro work before you decide if you want to go further. Just something to consider. Even if you end up buying a dedicated macro lens you'll still be glad you have the 50 1.8 in your bag whenever you have to shoot indoors or in low light.

yooperdooper

thanks for the info.i graduated fro michigan tech and have traveled extensively in the UP,it is my favorite place to do photography.actualy my favorite place in the world.thanks again

hugoender

Tim Kamppinen wrote:

3. The most important thing to note is that they will not work with all lenses (this is coming from my experience with Nikon lenses but I'm guessing it's the same with canon). They only are useful if your lens has an aperture ring. Many new Nikon lenses and I'm guessing canon lenses as well do not have this, and aperture is controlled strictly by the camera. What this means is that when you take the lens off of the camera the aperture is no longer adjustable and on the lenses that I have used it automatically stops down to the smallest aperture available. So you could use it with the tube but you'd be stuck at f-22 or whatever with no adjustability. A lot of times you want to use the smallest aperture possible to maximize the extremely narrow depth of field, so this might work out ok, except that when your lens is stopped down that far you probably won't be able to see much in the viewfinder and will have huge problems focusing, if you can see anything at all. Again, if your lens has an external aperture ring that you can set this isn't a problem because you can adjust it yourself. You'd probably want to focus at your largest aperture and then manually switch to whatever aperture you desired for the shot before hitting the shutter. Obviously you'd need a tripod to do it like this.

This is incorrect. The camera can control the aperture of the lens even with extension tubes. I have the Kenko extension tube set and they allow the camera to control the lens just as if the lens were mounted directly on the camera. I don't know what extension tubes you are using but normally they come with the contacts so as to allow the signal from the camera to reach the lens.

pathfinder

Both of you are correct I suspect.

The Kenko digital tubes for Canon does make the electrical circuits for aperture and exposure, but some older extension tubes were simply that - tubes that extended the lens further from the image plane/camera body and did not make any electrical connections, hence the lens aperture had to be set manually, as some Nikon older lenses still require.

Tim Kamppinen

Yeah, my statement about the aperture rings on the lens was in reference to the cheap $15 direct-from-hong-kong rings that I have. The much better (and much more expensive) kenko rings will work with G series lenses and whatever the canon equivalent is. Sorry for the confusion, when I posted that I don't think I even knew about the kenko rings.

Art Scott

If you are truoy serious about getting into the world of Macro and can afford it.....a good long macro lens of 100-180mm would be the way to go.....as they allow a larger working distance from subject......I am sure one of Pathfinders articles he linked to expalins all that also......as for which lenses to buy.....your Canon lenses will cost you the most.....but since you already own Sigma....well I would look into the Siggy 105-180 ...... I know I hated working nose to nose with my macro subjects when i was shooting with tubes.....just did not give me the room for flash or reflectors to work easily....at least not for me.........now if you had a lens suvhas a 70-200 macro (not a true macro but most are 1/3 lifesize instead of 1 to 1) then an extension tube set would be good as most of the 70-200 zooms have a close focusing of around 36-40 inches and a tube set would bring you in closer to that 1 to 1 true macro shot................A good macro prime will also make for a good portriat lens down the road if one decides to swing that way also.

pwp

Sorry, off topic, but another MTU alum here as well! I'd love to see some shots of the final results. I miss the UP terribly and imagine it would be a great source of inspiration!!