Filter sizes

[Syx]

Is it worth me getting a specific 72mm CPL filter, or should I just get a 77mm and a step up ring? 77mm is far more popular, and I'm thinking it might save me some cash in the long run, rather than having lots of the "same" filter?

 

[Wail]

Personally, if the size is one stop lower, I would go with the stepping ring. Put the price of the 2nd CP towards getting a better one in the first place.

 

[jerry12953]

If you're planning to use it on a wide-angle, the stepping ring method is more likely to produce vignetting, especially on full frame.

I had to get a new CPL when I converted to full frame format, because I had been using a stepping ring on cropped format.

 

[Syx]

Thanks guys. At the moment I've got a 72mm and a 55mm lens so was just wondering if it would be worth investing in the 77mm now rather than later due to their popularity.
As it stands I'll just stick with the 72mm CPL.

 

[Canon Bob]

If you're planning to use it on a wide-angle, the stepping ring method is more likely to produce vignetting, especially on full frame.

I can't quite see how. The stepping ring is shallower than a CPL so I would conclude that there's less likely to be vignetting than using a CPL of the correct size.

The downside of stepping rings is that the filter needs to be removed before fitting the lens cap (unless you get a cap for the CPL) and the hood won't fit.

Bob

 

[jerry12953]

I can't quite see how. The stepping ring is shallower than a CPL so I would conclude that there's less likely to be vignetting than using a CPL of the correct size.

The downside of stepping rings is that the filter needs to be removed before fitting the lens cap (unless you get a cap for the CPL) and the hood won't fit.

Bob

I assumed it was because the outer edge of the CPL is further from the outer element of the lens and therefore more likely to be visible.

Whatever, buying a new correctly sized low profile CPL when I went full frame did stop the vignetting at 24 on a 24-105 lens.

 

[Canon Bob]

I'll have to try a bit of trigonometry on that one Jerry. There's clearly an angle where the stepped up CPL would be visible in the fame but how wide that is, I'm not sure.

Bob

 

[jerry12953]

I'll have to try a bit of trigonometry on that one Jerry. There's clearly an angle where the stepped up CPL would be visible in the fame but how wide that is, I'm not sure.

Bob

I suppose it could just have been the lowprofileness of the new one?