Canon 20mm macrophoto lens

tpe · Post by **tpe** » Sat Apr 19, 2008 1:42 am

Does anyone have any experience of the Canon 20mm 3.5 macrophoto lens, and if so how much should i pay for one?

thanks

tim

Harold Gough · Post by **Harold Gough** » Sat Apr 19, 2008 2:02 am

I have had one from new for about 25 years. I used it to get pictures of the beelouse Braula on honeybees. It seemed to do a very good job but in those days I was using manual flash with this manual diaphragm lens and it was very time-consuming.

Since then, I have obtained the Zuiko 38mm auto diaphragm bellows lens, and, very recently, the 20mm version. Thus, I may never use the Canon one again.

A few years ago I saw the Canon one for a very low price and none since, until a few weeks ago, when a mail order dealer offered one for 200GBP. Such rare items are very diffcult when it comes to a fair price, as you have no reference point.

Also, you need the microscope threaded adapter to go with it, another rare and expensive item.

Harold

tpe · Post by **tpe** » Sat Apr 19, 2008 4:57 am

Ahh, thank you very much Harold, that is good to know, it does not have an adaptor, but i have bodged one together earlier out of plastic tubing that may still work so i can try that.

Another alternative is to ask a guy i know who makes camera adaptors to think aout making one. He does it commercially, and i had thought about asking him before but i did not know that they existed, i was just going to give him my 'bright' idea

.

Is there anything that should be taken into account other than getting them to fit the bellows and lens? He could probably make something like an af confirm version that actually delivers the maximum apperture information to the camera. Also if there are any hints on using this lens it would be great to hear.

Thanks again

tim

lauriek · Post by **lauriek** » Sat Apr 19, 2008 5:26 am

Is this lens an RMS thread like the older Olympus 38/20mm lenses? If so you could use the Olympus mount... I think its called the PM-MTOB (This allows an RMS microscope objective or the Oly RMS lenses to fit on an OM system) - they come up on ebay occasionally, I've seen three recently - and a Canon-OM adapter, I presume these exist?!

puzzledpaul · Post by **puzzledpaul** » Sat Apr 19, 2008 6:08 am

I also have one of these lenses - bought about 10? yrs ago ... probably new. I say 'probably' because it was labelled as new / old stock in a local shop when they were 'rationalising their inventory' ... ie dumping FD gear.

It came with its own FD mount in a clear plastic bubble container.

Haven't really used it since 'going digital' ... and have more recently noticed it didn't score particularly well in some review / tests compared to Olympus / Nikon equivalents.

(Same site also reviewed its 35mm brother - which came out better (from memory) ... so should poss. have bought that instead as the shop also had one of those ... but I didn't have the info then)

Any personal judgement(s) will have to wait until I feel the need to use it (not currently set up for or interested in stacking ... pc wouldn't cope anyway

) ... but I've seen at least one stacked image (here) by Charlie K done with such a lens ... and whilst it was upto his usual impeccable standard, there did seem to be a difference (to my eyes) somehow that I fould hard to quantify.

Maybe colour rendition ... can't really remember.

Luckily mine has the FD baseplate / adaptor (as previously mentioned) ... but am also fortunate enough to have an RMS tap for future 'bodging' if/when such things become necessary

As regards use - presumably the usual would be to run some tests for best performance, then use the appropriate aperture? (prob around the 4 - 5.6 region?)

Btw - can't remember what I paid exactly - but wasn't into 3 figs (£)

It might have been used for the highest mag (cropped) pic on linked page - but really can't remember.

pp

http://www.geocities.com/paulthepuzzles/aamemory.html

Harold Gough · Post by **Harold Gough** » Sun Apr 20, 2008 1:35 am

Yes, it comes as puzzledpaul says, with the FD mount.

The is the OM version. I had one made up, with a matching T-Mount for OM.

http://www.alanwood.net/photography/oly ... tml#pmmtob

Then, after spending over 80GBP on this, I found the OM one in my kit!

I used my Canon 20mm with f8 set on the lens, an effective aperture of f90 on the extension. As I was dealing with brownish insects the colour renditon was not really tested.

Harold