Extension Tube Questions 70-200

I was really wanting to buy a 100mm Macro...

But ive seen a lot of posta where people use the 70-200 f/4 and a Kenko extension tube set....

I also really want a 70-200, if you are on a budget, and or just want a good slick setup.

Do you think going with extension tubes is good?

Heck yes. The 70-200 is nice for tubes because it already focuses fairly close, so you don't need a lot of tube-length to get magnification. The f/4 is good since tubes cause light loss, but with a start of f/4 you'll still have enough light to allow a Rebel or 20D to AF well.

However, you probably won't get 1:1 with any kind of working distance, so don't expect 1:1 unless you're working on inanimate objects. Even then you'll be so close that lighting the subject will be tough.

All in all the 70-200 f/4 and a set of tubes is a very good way to get near-macro shots.

im wondering how different 200mm with extension tubes would compare to for example a 100mm True Macro lens...

I know u get very good f/stop with the true macro lens, but im not trying to spend HUGE bucks on macro...

Im getting because i have more zoom (200mm), it would make up for the 1:1 ratio???

Hey stealth,

I currently use this set up and it works faily well. It's a ccheap solution to get into macro, but eventually i would like to get a true macro lens. The working distance is pretty good on the short end but on the long end 200mm you get pretty close to the subject...also depending if you stack all three tubes.

here's some stuff i've done with the combo.
https://photography-on-the.net/forum/showthre​ad.php?t=103350
https://photography-on-the.net/forum/showthre​ad.php?t=113935
https://photography-on-the.net/forum/showthre​ad.php?t=112400
https://photography-on-the.net/forum/showthre​ad.php?t=104069


Also i should add that because I'm using a lens know to be fairly sharp, even at 100% crop the images are pretty good.

It works, the working distance is ok. You focus with the zoom ring.

But:
the quality won't be great
the light loss is huge
you've got to shell out another 100 bucks for the collar of 70-200

>>the quality won't be great the light loss is huge<<

The quality is not bad, it simply will not be as great as what you can obtain from a true macro lens which is optimized for macro distances and which is flat-field corrected.

As for light lost, if you use short extension tubes the light loss is insignificant. As you approach 1:2 reproduction ratio, you have a fraction of an f/stop, and at 1:1 (extension length same as focal length) you have a full f/stop of loss.

No. You'll still need 200 mm of extension on a 200mm zoom to get 1:1 reproductionon the sensor (it's 100 mm extension ona 100 mm macro). The gain is in working distance -how far you can back up from the subject and achieve a givenmagnification. But 200 mm worth of tubes will give you a pretty ungainly combination, and I'd be worried about one of the intervening lens/tube/body connections breaking under the strain.

To gain more magnification, try using a 1.4xTC as well. This set up would give you about 1x life size if not more. See the following thread:

https://photography-on-the.net/forum/showthre​ad.php?t=92618