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05/15/2006 10:52:48 PM · #1 |
I have searched the forums, and found several threads on extension tubes, but none of them answered my question (please don't laugh too loud if it is a particularly dumb one).
I don't know if I understand this correctly, but here is how I see it.
Extension tubes are hollow, no optics.
There seem to be two types of extension tubes -
1) the more expensive ones which have all the electrical connections and contacts to let the lens and camera communicate.
2) a MUCH cheaper option that means everything needs to be set manually.
One example is here on ebay
Having to set focus manually isn't a problem at all.
The bit I don't understand is this: if there are NO electricals communicating between camera and lens, then how do you set the aperture and the exposure? Both require the lens to know what the camera wants it to do, so how can the cheaper set work?
Where am I going wrong in my thinking?
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05/15/2006 10:55:19 PM · #2 |
i would guess that you can't set the Av with that one in the link unless you have a full manual lens.
edit: a 20D will still meter even without the connectors. Just like using a lensbaby.
Message edited by author 2006-05-15 22:56:15. |
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05/15/2006 10:57:00 PM · #3 |
You're on the right track for sure! With those ebay cheapies, you'll need a lens that is completely manual, in other words it has an aperture ring with which you can set the aperture. You'll also need to focus manually. That second bit is really no problem, you'll be setting focus and and adjusting the subject distance to focus anyway. But that first bit, setting the aperture, that's the bugger. You really, really want to have the lens at full aperture until you press the shutter, and this setup won't do it.
My advice is, get the Kenko set from B&H. Cheaper than the Canon ones, every bit as functional.
Message edited by author 2006-05-15 22:57:38.
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05/15/2006 11:02:42 PM · #4 |
| Aha..... thanks, gentlemen :-) |
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05/15/2006 11:28:28 PM · #5 |
Wow! So I just realized that Canon has completely done away with apeture rings.
I know that Nikon is also going in this direction with their G type lens, but a lot of their lenses are still have have the apeture ring.
For me I prefer having the apeture ring. I just bought an old, manual Nikon film camera so that I can take a class on b/w darkroom stuff. I'm glad that I can use all my 35mm format lenses with both my D70 and my F3.
Btw, I'm just rambling... |
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05/16/2006 08:18:45 AM · #6 |
| Another vote for the Kenko tubes. I have genuine Minolta extension tubes now because that's what I was given by the insurance company when my Kenko tubes (and several thousand dollars worth of other gear) were stolen. But the Kenko tubes were every bit as good. If memory serves they even had the extra electrical connections used by K-M's (D) lenses. |
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05/16/2006 08:21:09 AM · #7 |
i'll second that
Originally posted by kirbic:
My advice is, get the Kenko set from B&H. Cheaper than the Canon ones, every bit as functional. |
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05/16/2006 08:26:50 AM · #8 |
Originally posted by hopper:
i'll second that
Originally posted by kirbic:
My advice is, get the Kenko set from B&H. Cheaper than the Canon ones, every bit as functional. |
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and I'll add a third.
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05/16/2006 10:01:45 AM · #9 |
| Dang it - I had hoped for a solution that would make the cheap set perfectly wonderful to use! :-) But thank you all for your advice, I'll just save up a bit longer. |
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