A 28 2.8 missing A lock button

**hman** · 02-01-2013, 08:20 AM

I have a Rokinon A 28 2.8. It is missing the button that locks/unlocks the A setting. If set as A, nothing actually moves, but I would like to know what I can use to keep it in it's A setting permanently without ruining the lens.

Another question: I also have a Focal M 28 2.8. The Rokinon diameter is 52, the Focal is 55. What effect if any does lens diameter have. I am trying to decide which to keep. Both are in great condition, and I like the A option on the Rokinon; image quality on both is fine, but I don't need both.

Thanks!

vladimiroltean · 02-01-2013, 09:21 AM

Originally posted by hman

Another question: I also have a Focal M 28 2.8. The Rokinon diameter is 52, the Focal is 55. What effect if any does lens diameter have

For filters. 52mm size is more common than 55mm, and the vast majority of Canon and Nikon lenses share this diameter. However, in the Pentax world, 49mm is even more common.

02-01-2013, 08:20 AM	#1
hman Site Supporter Join Date: Jan 2010 Location: WEST CHESTER, PA Photos: Gallery Posts: 299	A 28 2.8 missing A lock button I have a Rokinon A 28 2.8. It is missing the button that locks/unlocks the A setting. If set as A, nothing actually moves, but I would like to know what I can use to keep it in it's A setting permanently without ruining the lens. Another question: I also have a Focal M 28 2.8. The Rokinon diameter is 52, the Focal is 55. What effect if any does lens diameter have. I am trying to decide which to keep. Both are in great condition, and I like the A option on the Rokinon; image quality on both is fine, but I don't need both. Thanks!

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02-01-2013, 09:21 AM	#2
vladimiroltean Veteran Member Join Date: Dec 2010 Location: Bucharest, Romania Photos: Gallery Posts: 1,465	Originally posted by hman Another question: I also have a Focal M 28 2.8. The Rokinon diameter is 52, the Focal is 55. What effect if any does lens diameter have For filters. 52mm size is more common than 55mm, and the vast majority of Canon and Nikon lenses share this diameter. However, in the Pentax world, 49mm is even more common.