303 wrote:
So to obtain a 1:1 magnification with a 200mm lens i would have to add on extension tubes untill i get 200mm. This would cost more than getting an extension tube of 50mm for my 50mm lens to get the same 1:1 magnification. But with the 200mm lens i wouldnt have to be as close to the subject to get the desired 1:1 magnification?
Is this correct?
But if it's a 80-200 lens, you'll only need 80mm of extension for 1:1 if it's zoomed all the way out.
You'll be able to get closer to your subject and get a closer image at 80. If you switch to 200mm, you gain working distance but will sacrifice zoom (how large the object apears).
I have the Kenko set and can use it with my 50 1.8 to pull out detail from sand. A pea would fill most of the image. When I use it with my 70-200, I can get gradually farther from the object but it won't be as close to 1:1.
Since it's 3 pieces, you can also create several levels of extension to get varying distances from your subject and thus changing how big the object appears.
I love them, they're great!
Also, with all of the problems I've had with the nifty fifty at 1.8 up close, that seems to go out the window when using these tubes. It seems (so far) that what I see is what I get when it comes to depth of field and focal points. Of course I'll do more testing, but so far I like the extension tubes.
As far as the Kenko tubes "not feeling strong enough" I haven't really found a problem. Even with the 70-200 on the end of all 3, it seems solid enough. That being said, I don't think I'd want to mount that on a tripod and use it for a while... unless I had a collar (which I don't).
The 50mm works great with it and you can get incredibly close. Take the big tube out and you're closer to the same results as the 70-200 with all of them on.