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Reverse Rings and Extension Tubes

chrisboyne

New Member
I am interested in getting a set up for doing some macro work. I cannot afford the CZ 60mm macro right now and am looking for alternatives. I have a CZ 50mm 1.7 and a CZ 28mm 2.8 so I have been looking at reverse rings and extension tubes.

All I am really looking for is a 1:1 ratio. Can I achieve this using my 50mm and a reverse ring? Are their benefits to using reverse rings over extension tubes or the other way around?

I noticed that extension tubes come in different lengths. It seems possible to buy them in sets too. What are the different lengths for? Like would one be 1:1 then another 1:2 then another 1:3 or that kind of thing? If so, what length tube with a 50mm lens would allow for shots be taken with a 1:1 ratio?

Thank-you in advance for your information.
 
> [Chris, Check on a Yashica ML 55mm macro lens. Superior results & much lower cost than CZ. I prefer extensions over reversing rings. Another way to go is with a bellows set up.]
 

swoolf

Well-Known Member
The Contax ext. tubes come as a set with 13/20/27mm tubes - you can use these or various permutations of these to give different magnifications . Used together you can get 1:1 , I use mine with my 50mm all the time[and get excellent results] although sometimes a longer focal length would be nice to give you more working distance between lens and subject . You can also get a 7.5mm tube but this does not have automatic stop down functionality etc - as a result I hardly ever use this , or the reversal ring which I also have.... Steve
 

bobbl46

Well-Known Member
Further to last post

My experiments with Zeiss 50mm f1.4 MM and extension tubes show that results are acceptable in the center at 1:1 (50mm of extension) but have noticeable lower performance at the corners, This is why Zeiss and all other lens manufacturers limit the standard lens minimum focus to about 0.5m! They are computed to perform at their best near infinity down to their normal minimum focus. Macro lenses are designed to produce optimum performance at “macro” distances!

Short extensions like 13 & 20mm give good results with the Planar, but we are not talking 1:1 ratio he... beyond (the critical will say including!) that, it’s the law of diminishing returns! Regard bellows as variable extension tubes!

The results using a reversing ring were very good all ove...but the range of magnifications (i.e. range of focussing) is very limited... and, of course, you have no automatic functions. The working distance is quite short too!

The Yashica 50mm and 100mm macro’s are very good... but what about the often forgotten , and inexpensive, 2x Macro converter?

See post above for links about 2x Macro convertor.

Cheers, Bob.
 
J

John_bird

Hi Chris,
How about being a bit more specific about what kind of macro work you are interested in, as for different situations I use the following in this order 300mm 5.6 tamron SP2 with or without extension tubes 90mm 2.5 tamron macro again with or without extension tubes Contax 85mm 2.8 with extension tubes and 28mm 2.8 with extension tubes.
I have expermented with reverser ring but that was not suited to my working method and subjects
I use the 300mm for butterflys mainly the 90mm for wild flowers and insects if there is sufficiant light I prefer the CZY 85mm with extension tubes, the 28mm CZY with extension tubes I only use when I require its exagerated prespective. remember if you use a reverser you will loose all automatic diaphram control but I think with extension tubes will produce a highly corected high res system mainly of use for copying flat originals ie stams coins ect.
Hope this is of some use John
 
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