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Question: Can I use this Macro flash with a Canon EF 50mm f/2.5 Macro Lens? (Thank's - in advance)
Document: It also provides two smaller lamps to aid auto-focusing in dim conditions. It can even serve as a master controller for off-camera Canon Speedlite flash units. It is powered by four AA batteries; rechargeable NiMH batteries are recommended.The MR-14EX mounts easily on theCanon EF 50mm f/2.5 Compact Macro Lens, theCanon EF 100mm f/2.8 Macro USM Lens(now discontinued), and theCanon MP-E 65mm f/2.8 1-5X Macro Lens.
After using my Canon EF 100mm f/2.8L IS Macro lens for a year without this flash, I was pleasantly surprised at how many more successful photos I can get with it. The flash enables me to use a fast shutter speed, small aperture and low ISO to freeze the movement of the petals when it is slightly windy outside. I can also use it handheld where I normally would only consider using a tripod.
A macro ring light like this is optional equipment if you use Canon's 50mm, 60mm, 100mm, or 180mm macro lenses. But either this flash or the more expensiveCanon MT-24EX Macro Twin Lite Flash for Canon Digital SLR Camerasmacro flash is really absolutely required equipment if you use theCanon MP-E 65mm f/2.8 1-5X Macro Lens for Canon SLR Cameraslens, especially if you do not always use a tripod.
Canon makes a Great product to be able to connect the Canon MT-14EX Macro Ring Lite to the Canon EF 100mm f/2.8L Macro IS USM L Lens. The adapters that Canon make are specific for certain Lenses, otherwise you coudn't use the Canon MT-14EX Macro Ring Lite on other lenses due to their different ring / filter size, because lens barrels usually differ.
However, it would have been nice to know ahead of time that to use it with the Canon EF 100mm f/2.8L Macro the &#34;Canon Macrolite Adapter 67&#34; is needed.so it was somewhat disapointing.
To mount it on theCanon EF 180mm f/3.5L Macro USM Lens, a Canon Macrolite Adapter 72C f/ML-3 is needed. On some other lenses, it can be mounted with reasonable stability simply by attaching an appropriate 58mm step-up ring to the lens. I have done this with aTokina AT-X 100mm f/2.8 PRO D Macro Lensusing aKenko 55mm Step-Up Ring to 58mm.
But I find the MT-24EX's light to be more harsh than this MR-14EX, unless you create your own diffuser setup for it.July 22 2010 update: Since my original writing of my review, I sold myCanon EF 100mm f/2.8 Macro USM Lens for Canon SLR Camerasand bought the newerCanon EF 100mm f/2.8L IS USM 1-to-1 Macro Lens for Canon Digital SLR Cameras.
This Macro Ring Lite offers a fairly reliable solution to the problem. You could also invest in theCanon EF 100mm f/2.8L IS USM Macro Lenssince the L-series comes with image stabilization and is very well reviewed, but there are many situations where I could see needing the Macro Ring even with the L-Series w/ IS. That and the L-series lens is almost $900. But that upgrade will probably come in due time.
The Canon MR-14EX was a perfect addition to my macro photo equipment. It snaps onto my 50mm compact macro lens quickly and easily and illuminates extreme closeup subjects that a regular on-camera flash could not reach, and it saves futzing with an off-camera extension flash.My only beef is that the inside diameter of the ring is too small to fit larger diameter lenses (I often like to use my sharp Canon 24-70mm lens with macro rings for extreme macros).
I bought the Canon MR-14EX Macro Ring Lite to go along with myCanon EF 100mm f/2.8 Macro USM Lensto be used on aCanon EOS 7D 18 MP CMOS Digital SLR. I really haven't explored extreme macro photography before, so I thought I might as well see if it is something I could love. So as I do with most things I get interested in, I went a little nuts and bought a ton of equipment, including the Canon MR-14EX Macro Ring Lite.
Answer: I know that you have to buy a ring adapter to fit in between.without it, it won't mount.  It depends on the lense. Look for a ring adapter that is compatible with your EF50. Good luck.