blanam Loc: Detroit

If you want to get 1:1 and greater magnification you can use a reversing ring.

This first two will connect your 50mm lens to the camera BACKWARDS. You will get best results if your 50mm lens is of the style with an aperture ring, so you can adjust the aperture. You will be shooting manual exposure and manual focus.

$8.00: https://www.amazon.com/Fotodiox-Filter-Thread-Reverse-Adapter/dp/B003Y6182Q/ref=sr_1_10?crid=R2KML2I0XLA7&keywords=49mm+reverse+ring&qid=1558478817&s=electronics&sprefix=49mm+rever%2Celectronics%2C155&sr=1-10
$15.00: https://www.bhphotovideo.com/c/product/82187-REG/General_Brand_AV49PK_Reverse_Adapter_Pentax_K.html

This second link is for multiple reversing ring choices. These type will backwardly connect a second lens to the first lens on the camera. Again, a lens with an aperture ring works the best, but on the legacy lenses that have an aperture lever, can be used and just tape the aperture open. The second/reversed lenses aperture will have no effect on DOF, so using it wide open is fine. For example (using a 49mm to 49mm reversing ring) you can use your 100mm lense as the first/camera mounted lens and the 50mm as the second/reversed lens, you will have a ~2:1 macro (100/50): https://www.amazon.com/BEESCLOVER-Thread-Reverse-Adapter-Provide/dp/B07PZ6TJWH/ref=sr_1_14?crid=R2KML2I0XLA7&keywords=49mm+reverse+ring&qid=1558479478&s=electronics&sprefix=49mm+rever%2Celectronics%2C155&sr=1-14

I've used this setup on a Nikon camera with a zoom 55-200mm and a Pentax 50mm for a ~4:1 macro. That's 4x larger than life. For $80 you can buy an old 50mm Pentax or Olympus or Nikon with an aperture ring, then just get the right size reversing ring and you're all set.

pminyard Loc: Bartlett, Tennessee

I have a set of excellent Kenko tubes that I use with my Canon. The first thing I did after the purchase was to clean the contacts with electrical contact cleaner and apply a very, very light coating of an anti-oxidant compound on the contacts. The anti-oxidant originally came into play to combat the galvanic corrosion behavior of the joining of dissimilar metals, such as aluminum to copper, but is excellent for any metal to metal contact. There are lots of choices. An excellent one is Nyogel 760G. Even with gold plated contacts, a thin film seals the microscopic pores of the plating and guards against scratches and substrate oxidation (blooming).

If I had purchased the canon tubes, I would have still done this same application. This practice is a holdover from audio builds.

Be prepared to learn "focus stacking" as extension tubes = very narrow depth of field!

OutdoorOldie

Thank you!
annie