Stup-up and step down filter rings

<p>So I thought this was easy but apparently I got it wrong so I need help.<br>

I have an 82mm tiffen nd filter which I use on my canon 24mm tse. I wanted to use the filter on my 70-200 which requires a 77mm filter so I bought a step down filter thinking it would make it fit but FAIL. the adaptor ring does on fine to the filter but is to big to thread into the 70-200. What should have I gotten?</p>

<p>Thanks<br>

Felix</p>

 

<p>Step rings are always LENS -> ACCESSORY. A smaller lens thread to a larger accessory thread requires a step-<strong>up</strong> ring, and a larger lens thread to a smaller accessory thread requires as step-<strong>down</strong> ring.</p>

<p>So if your lens filter thread is 77mm, and you want to attach an 82mm filter, you need a 77->82mm step-<strong>UP</strong> ring, since you are stepping <strong>up</strong> from 77mm (lens) to 82mm (filter).</p>

<p>Hope that makes sense. :)</p>

<p>Felix-you need a step up filter ring; in this case, a 77 to 82 mm step up ring. I use a 49 to 52mm step up ring which allows me to use a 52mm filter on my 49mm lens.<br /> I know it can be confusing! regards, cb :-)<br>

Edit: posted at the same time as Michael.</p>

<p>Unless I've missed something, it sounds like the lens side of the adapter ring is not actually 77mm. Are the thread sizes marked on the ring at all?</p>

<p>Thanks guys so I basically did it backwards. thanks</p>

<blockquote>

<p>Unless I've missed something, it sounds like the lens side of the adapter ring is not actually 77mm. Are the thread sizes marked on the ring at all?</p>

 

</blockquote>

<p>Normally the step-up ring will be marked something like the one below:</p><div></div>

<p>For what it's worth, filter adaptor rings are almost always step-up. That's for the simple reason that a bigger fiilter is big enough to cover the front of a small lens, but not the other way around.</p>

<p>"Stepping down" is likely to cause vignetting, but there are reasons and conditions where it is necessary or useful. Places like http://www.adapterrings.com/ sell both.</p>