I'm not sure if this is the right place to ask but I'm going to try. Could someone explain what an extension ring is used for? I have read that they are used in macro photography but I'm not sure just what for.
#1. "RE: Extension Ring?" | In response to Reply # 0Merlin Basic MemberWed 27-Sep-00 04:03 AM
This is an easy one. Have you ever focused on your coffee cup at breakfast time - very few wives tolerate this, by the way - and wished you could focus just a bit closer on that Garfield logo? You wind your lens out as you get closer, and - thump! You've reached the end of its travel, and it won't extend any more. You have not just the cup in the frame, but half the kitchen too.
What you need is something to make the lens extend a bit further. This is where an extension ring helps you out. It fits between the lens and the camera, allowing just a few more centimeters of forward travel for the lens. Now you can get just the Garfield logo framed.
Everything in photography involves compromises, and you have to accept a couple of trade-offs with extension rings.
First, unlike a bellows unit, which has one heck of a range, extension tubes are rigid. Only a limited range of extra magnification is possible. Another potential problem with macro photography without a macro lens is that most non-macros tend to distort the image a bit at short ranges. A Micro-Nikkor, for instance, is specifically designed for flat-field close up work, and gives its best performance at these distances. The fact that it also works well at infinity is a free bonus.
An extension ring is a cheap way of getting close-ups that wouldn't otherwise be possible, and generally a good investment.
Isn't this a great place to learn how to spend your money?
#2. "RE: Extension Ring?" | In response to Reply # 1frankie Basic MemberWed 27-Sep-00 08:55 AM
I've got an old M2 ring. I didn't know really what it was or what F line it was for when I bought it. I payed about 10$ US for it (maybe less - can't remember - Ebay)... They're usually no more than 60$ new... All you have to do, is if you have multiple lenses, you have to fiddle a bit to see which lens it works best with. I found mine to work best with my 70-210... The 28-80 was a bit wonky at really close range.
I had to remove the little armature that couples the aperature stop-down to the camera because it eliminates all meter couplings. So it basically works like by stop-down metering and it's great for the price!