Canon or Kenko tubes?

John_B wrote in post #2417375
Dchemist,
Plastic?
Hmm... mine are solid metal

Mine were plastic also, the barrels that is, the mounts are metal. But so are the Canon ones.

In fact they look almost identical, the Canon ones just lockup tight.

I suspect there is a lot more tolerance variation on the Kenos thus my problem. I guess I could have returned them but I am not sure I would have trusted replacements. Besides it was right in the main season for using them so I needed them right then.

If you're going Macro, why hold back:

http://www.canon.co.uk …5844&SourcePage​ID=26387#1

Thanks AdamJL. I definitely considered the MP-E65 lens for a while, but I don't believe I'll be going THAT macro anytime soon. I just want to dabble a bit with a few ideas here and there. If it's something I decide I want to delve into, I'll then give more consideration to the the MP-E65, as it sounds like an impressive lens.

WT

RE: Kenko Vs. Canon,

the time that one really must consider the extra $$ for the Canon tubes is when the intended use includes the long telephotos.

I was very happy with my kenkos on all my lenses up to the 100-400mm,.
But when hanging a 1D off the back of a 500mm prime, the much more substantial Canon tubes are definitely a worth while extra cost.

For all else, I would still be happy with the Kenkos

William Taylor wrote in post #2419962
Thanks AdamJL. I definitely considered the MP-E65 lens for a while, but I don't believe I'll be going THAT macro anytime soon. I just want to dabble a bit with a few ideas here and there. If it's something I decide I want to delve into, I'll then give more consideration to the the MP-E65, as it sounds like an impressive lens.

WT

Yes, the MP-E is a fantastic lens. In fact most bugs (at least in the UK) are small enough that the MP-E is the lens of choice even with a crop camera. The smaller working distance does put tighter constraint on stalking however.

Tubes will be useful for lots of things so its worth getting a set. As I have a 100mm macro and a MP-E I mostly use the tubes with the 300 f4L IS.

Must admit I've had no problems with my Kenkos, and I've used them a lot. I must also admit, I haven't used them with heavy zooms, only with a Sigma 105 macro.

I had problems with the Kenko tubes not locking the lens in....never a problem with the Canon tubes....

Thanks again for all the information!

I've noticed a number of people mention that they've used their tubes with their telephotos, many of them being the 300mm. Is there a way to calculate the new minimum focusing distance when attaching the various tubes to your telephoto? For example, my 300 f/2.8 has a MFD of just over 8 feet. What new MFD can I achieve using the Kenko tubes (I assume stacking them together improves this value as well, though I would be hesitant to do this using my 1D Mk2n with the mention of the possible loseness of the attachments).

Thanks,
William

William Taylor wrote in post #2424326
Thanks again for all the information!

I've noticed a number of people mention that they've used their tubes with their telephotos, many of them being the 300mm. Is there a way to calculate the new minimum focusing distance when attaching the various tubes to your telephoto? For example, my 300 f/2.8 has a MFD of just over 8 feet. What new MFD can I achieve using the Kenko tubes (I assume stacking them together improves this value as well, though I would be hesitant to do this using my 1D Mk2n with the mention of the possible loseness of the attachments).

Thanks,
William

Cannon privide magnification, focus distance and working distance for their tubes but only with one tube connected at a time. There are equations but they are difficult to apply accuratly to internal focus lenses away from infinity focus.

I have a table on my macro page of rough measurements made with the kenko tubes before I switched to Cannons here

http://www.zen20934.ze​n.co.uk …ent.htm#Extensi​on%20Tubes

Select "Extension Tubes" from the TOC if the link does not take you direct there.

For example the max magnification with the 300mm was ~0.58X

Thanks Lester. Nicely done page, btw.

William