Need help with step-down filter ring.


Status
Not open for further replies.

ArchRival

New Member
Sep 17, 2006
559
4
0
#1
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

Senior Member
Nov 28, 2005
19,105
12
0
#2
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

New Member
Sep 17, 2006
559
4
0
#3
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

New Member
Jul 23, 2008
521
0
0
Upper Bukit Timah
#4
As long as you're using a step-down ring, vignetting will occur - you're effectively "blocking" the lens.
 

Rashkae

Senior Member
Nov 28, 2005
19,105
12
0
#5
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

Senior Member
Mar 24, 2006
883
3
18
www.sgwriter.com
#6
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.
 

Rashkae

Senior Member
Nov 28, 2005
19,105
12
0
#8
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

Moderator
Staff member
Sep 27, 2004
21,903
46
48
Punggol, Singapore
www.foto-u.com
#9
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??
 

Rashkae

Senior Member
Nov 28, 2005
19,105
12
0
#11
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

New Member
Jun 5, 2009
611
0
0
Singapore
#12
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

New Member
Sep 17, 2006
559
4
0
#13
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

New Member
Sep 17, 2006
559
4
0
#15
Perhaps i should mention the lens is on a 400D with APS-C sensor.
 

Reim1o

New Member
Jun 14, 2008
180
0
0
Melbourne, Australia
redbubble.com
#16
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?
 

jaRv1s

New Member
Jun 5, 2009
611
0
0
Singapore
#18
special effect filters? all my filters added up (3UV 1CPL 2 Step-up rings) also haven't reach 200 le... :sweat:
 

ArchRival

New Member
Sep 17, 2006
559
4
0
#20
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.
 

Last edited:
Status
Not open for further replies.
Top Bottom