Step up, step down lens adapotor help.

C

Chris seager

Messages
245
Name
Chris
Edit My Images
Yes
So buying a Variable ND filter but not sure what size to get. Biggest lens thread it needs to fit is a 72mm and second biggest is 67mm.

My question is would a 67mm Filter work on a 72mm(200L Prime so not exactly much zoom) step up or would their be any vignetting ?
 
Chris seager said:
So buying a Variable ND filter but not sure what size to get. Biggest lens thread it needs to fit is a 72mm and second biggest is 67mm.

My question is would a 67mm Filter work on a 72mm(200L Prime so not exactly much zoom) step up or would their be any vignetting ?
Click to expand...

Cut out a 67mm hole in a peice of card, hold it over the end of the lens and snap away and find out :thumbs:

I'd always go for the bigger filter though IMO
 
My guess is that it would probably clear okay, but those vari-NDs are not good for sharpness on longer lenses. And on wide-angles, you get a dark cross shape appear at higher ND settings :thumbsdown:

They use cross-polarisers, which is technology for dimming theatre/film/video lights. It's just not very good for lenses.

Is it a LightCraftWorkshops one? Their fixed nine stops ND500 is good though.
 
HoppyUK said:
My guess is that it would probably clear okay, but those vari-NDs are not good for sharpness on longer lenses. And on wide-angles, you get a dark cross shape appear at higher ND settings :thumbsdown:

They use cross-polarisers, which is technology for dimming theatre/film/video lights. It's just not very good for lenses.

Is it a LightCraftWorkshops one? Their fixed nine stops ND500 is good though.
Click to expand...

Yer it is a Light Craft one. And I would mainly be using it for film. Its Just id like to be able to use at least 2 lens hoods with the filter hence wanting a step up ring.

And is the reduction in sharpness noticible ?
 
Chris seager said:
Yer it is a Light Craft one. And I would mainly be using it for film. Its Just id like to be able to use at least 2 lens hoods with the filter hence wanting a step up ring.

And is the reduction in sharpness noticible ?
Click to expand...

You mean film, as in not digital, or video? Not sure what you're trying to do.

The reduction in sharpness depends on your needs, and how closely you look. 7D users with L lenses tend to look fairly closely ;)
 
Yer sorry i did mean video.
From the website.
"To avoid vignetting, we use 1 stop larger front glass. e.g. a 77mm Fader ND, equips with a 77mm back thread (attach to camera lens), and a 82mm front glass/ filter thread."

I think i might just go for the 67mm and risk the step up ring.
 
I may be slightly confused... but can't see why you'd want to standardise on the smaller filter size, rather than the larger one. Stepping up in size is always going to be less risky for vignetting etc, and gives you more space at the edges which means you don't have to clean all the way into the corners.

In your case i'd get the larger filter, and a step-up ring for your 67mm lens. I've got loads of stepping rings now, in all combinations for 52/58/72mm filter rings. Don't use them that often at the moment, but all my best filters are 72mm.

One other thing, i got all of mine from eBay, but would suggest it's worth paying an extra £2ish rather than getting the cheapest ones - the best one's i've got recently were sold as "Kood", from a seller called crookedimaging. Seems to be much better quality than some of the marginally cheaper HK/China imports - one i bought recently was reeally badly machined and finished, really wouldn't want to us it much as i can imagine it damaging the threads on the camera / filters.

David
 
Ah, good point about the hood. I only have a "proper" hood for my biggest lens, the 72mm. The others i use cheapie screw-in hoods for my 58mm lenses, so no problem using the step-up from 52-58mm. In which case, i'll get back in my box and be quiet ;)

David
 
You must log in or register to reply here.
Back
Top