Posted by beth summer on September 17, 2009 at 5:32 PM
I know this is a silly question but here goes. I have a 72mm size lens and I'm thinking of getting the Vari ND Singh Ray filter which is 77mm. So...do I need a step up adapter ring of 77 to 72 or a step down adapter ring of 72 to 77? I can never remember which way I'm supposed to go!!! Even after looking at B&H description, I'm still confused. Obviously, I need help Thanks....
Beth, if the lens is 72mm and the filter will be 77mm, you will need a step up ring. Most products will list the sizing accordingly and not just by step up or step down. It should say step up from 72mm to 77mm.
In most cases it is better to have to step up instead of down to prevent any vignetting that might come from additional items being stacked on the front of the lens.
Posted by Buck Ward on September 17, 2009 at 9:39 PM
Beth
I have a couple of these. A B+W and a B&H General Brand, 72mm to 77mm step up rings. I didn't expect quality to be an issue, but I can't screw the General Brand onto one particular lens but I have no trouble with the B+W. With some difficulty I can screw it onto another lens. The B+W fits both with no hint of a problem.
Posted by beth summer on September 18, 2009 at 9:05 AM
Thanks Paul and Buck. I was pretty sure it was a step up so now I just need to decide whether to buy the Vari ND or not.
Go with the B+W brand Beth. They're brass and more expensive, but worth every cent. The cheaper aluminum rings are badly prone to binding and sticking, especially with even a tiny bit of dust in the environment. You'll become much too familiar with SFS (stuck filter syndrome) when using the cheaper versions. And if you think it's hard to get a stuck filter off a lens, try getting a stuck ring off a filter!
Posted by beth summer on September 23, 2009 at 3:14 PM
There is supposed to be a logic to the naming. The lens has a filter thread size. If you want to put a larger filter on it, you step up to a larger size with a step-up ring. If you want to put a smaller filter on it, you will need to step down. I used a 82/77 step down ring for mounting a macro diopter on a 300 telephoto, but otherwise I've never stepped down.
Grabbing a flexible ring from the sides and twisting harder is counterproductive. When a filter or a stepping ring seems stuck, a good approach is to put a grippy sheet (eg: jar- opening sheet or dental rubber) on a flat surface and push the stuck thing face-down on the sheet, then try unscrewing it. This has worked well for me.
Discussion
6 repliesIn most cases it is better to have to step up instead of down to prevent any vignetting that might come from additional items being stacked on the front of the lens.
This should be the one you need.
B&H General Brand 72mm to 77mm
I have a couple of these. A B+W and a B&H General Brand, 72mm to 77mm step up rings. I didn't expect quality to be an issue, but I can't screw the General Brand onto one particular lens but I have no trouble with the B+W. With some difficulty I can screw it onto another lens. The B+W fits both with no hint of a problem.
Grabbing a flexible ring from the sides and twisting harder is counterproductive. When a filter or a stepping ring seems stuck, a good approach is to put a grippy sheet (eg: jar- opening sheet or dental rubber) on a flat surface and push the stuck thing face-down on the sheet, then try unscrewing it. This has worked well for me.
Pete D.