Need help with step-down filter ring.

[ArchRival]

I'm looking for a step-down filter ring to attach a 67mm filter to a 77mm lens. Does anybody know where to get one?

The lens will be operating exclusively at 24mm, F4 with the filter attached. Will vignetting occur?

Thanks for any information.

 

[Rashkae]

The lens will be operating exclusively at 24mm, F4 with the filter attached. Will vignetting occur?

What is the focal length? I'm assuming 24-70. Yes, you will have very heavy vignetting.

 

[ArchRival]

The lens i'll be using it on is a Canon 24-105 F4L. At 24mm, F4, the effective aperture should be only 6mm. Will vigetting still occur?

 

[daniel0ng]

As long as you're using a step-down ring, vignetting will occur - you're effectively "blocking" the lens.

 

[Rashkae]

Yes it will. And you need to review the calculations a bit. It's not a perfectly linear formula in relation to the aperture size.

 

[Edwin Francis]

The lens i'll be using it on is a Canon 24-105 F4L. At 24mm, F4, the effective aperture should be only 6mm. Will vigetting still occur?

Not as simple as that. If you already have a 67mm filter handy, just hold it in front of your current filter (as an approximation of the step-down ring thickness) to get an idea.

 

[Daedalus Trent]

The lens will be operating exclusively at 24mm, F4 with the filter attached. Will vignetting occur?

Definitely.


Just a question though. Why do you want to attach a 67mm to a 77mm L lens? :dunno:

 

[Rashkae]

Definitely.


Just a question though. Why do you want to attach a 67mm to a 77mm L lens? :dunno:

Probably to save money on the cost of larger filters.

A bit of a waste to then invest in an L lens, really.

 

[catchlights]

The lens i'll be using it on is a Canon 24-105 F4L. At 24mm, F4, the effective aperture should be only 6mm. Will vigetting still occur?

the aperture is near the focal plant, hence it is very small.

if using a 67mm filter will not cause vignetting on a 77mm filter thread lens, why would the lens manufacture want to make this lens with 77mm filter thread in the first place??

 

[catchlights]

btw, if you insist, you still can use 67 filter filter, probably you will not have vignetting from 50mm onwards.

 

[Rashkae]

btw, if you insist, you still can use 67 filter filter, probably you will not have vignetting from 50mm onwards.

As he said, he's using it exclusively at 24mm.


So, TS... Why not just get a 24mm prime lens?

 

[jaRv1s]

definitely would get vignette bro...

frankly, i got a bit lucky that to know there's step up ring available before buying any filter... so i got only one polarised filter which is 77mm... other smaller ones just step up to 77mm then can use the polarised filter... while most lens got its own UV filter because too lazy to add step up ring and add UV filter when changing lens... and UV filter not so exp to save too...

TS, maybe you should consider selling your 67mm one and get the 77mm one plus other step up rings... since most of the higher end lens are with 77mm filter size (assuming you'll carry on to buy those higher end lenses)...

 

[ArchRival]

Not as simple as that. If you already have a 67mm filter handy, just hold it in front of your current filter (as an approximation of the step-down ring thickness) to get an idea.

Yes i did that and snapped a picture. No visible vignetting through the viewfinder and the image looked ok, but i'm not sure what happens at long time exposures.

 

[ArchRival]

Definitely.


Just a question though. Why do you want to attach a 67mm to a 77mm L lens? :dunno:

Well......the filter was about 1/3 the cost of the 24-105F4L.

 

[ArchRival]

Perhaps i should mention the lens is on a 400D with APS-C sensor.

 

[Reim1o]

Lets do the rough math:

77/67 = 1.149 < 1.6 crop

Most probably you won't get vignetting if your using cropped sensor
What kind of filter costs 1/3 of a 24-105?

 

[Daedalus Trent]

Perhaps i should mention the lens is on a 400D with APS-C sensor.

Oh...that explains a lot :bsmilie:
Well, if you tried it yourself then i guess it isn't a prob then.

and 1/3 the cost of your lens? :bigeyes: What filter is that?

 

[jaRv1s]

special effect filters? all my filters added up (3UV 1CPL 2 Step-up rings) also haven't reach 200 le... :sweat:

 

[Reim1o]

My most expensive filters are 77m IR and hot mirror, bought for 120usd each.
Even B+W 77mm CPL is only around 150usd

 

[ArchRival]

Thanks for the replies, dudes. Filter rings are cheap, so i went out to get a 77-72 and 72-67. Here are some test shots.
All are with the 24-105 F4L on Canon 400D body.

Top: 24mm F4 with 77mm UV attached.
Bottom: 24mm F4 with 67mm UV filter on the rings attached to 77mm UV filter.

Top: 105mm F4 with 77mm UV filter attached.
Bottom: 105mm F4 with 67mm UV filter on the rings attached to 77mm UV filter.

Conclusion is you can use a step down of 77mm to 67mm on this particular lens on an APS-C sensor body without much visible vignetting.