Graduated Filter - Advice Required

[vault]

Hi guys

I'm after some advice on which filters I should buy as I've seen two different fitting types available.

The circular type that screw onto the end of the lens with a rotating element
The Cokin type [square] that sit in a frame screwed onto the end of the lens

Having borrowed a frame & filters [Cokin type] from a friend I found the biggest issue was focusing as none of my lenses focus internally, the end of the lens rotates, and, the frame/filter moves!

However, with the circular type the elemnt rotates, so I'm assuming focusing should cause any problems..

Am I right/wrong in my assumptions?

Colin

[vault]

Anyone?

[Soul Of Nature]

Anyone?

Sorry no one else has got back to you , I have got the frame type which you can fit more than one filter also you can adjust the filters up and down to suit the gradiant ( grads ) required for a given scene , I think the benefit of this type is that you can just buy one filter holder then buy the various adaptors to fit each of your lenses ie : 58mm 77mm and such like , saves having to buy all different sizes , also the Lee filters will fit the cokin Z holder , just gives you a lot more choice ....I tend to set my lens for the shot then just slide the required filter in , I'm no expert , but I hope this helps

[carronade]

I would have thought that if the front element rotates then so does the filter.
So if you have a graduated filter then where in the frame the graduation starts will vary according to how far round the element has rotated i.e the graduation may not be horizontal but any position.
Please correct me if I am wrong or if I have missed the point.
mark

[ST]

Colin

With the square style of filter (Lee,Cokin etc) you are correct with your description i.e. when attached to a lens which rotates during focusing the filter holde would also rotate. However once you have focused you can if you are careful rotate the filter hoder to the position you require (see 2 below). then recheck your focus, adjust if necessary (probably best manually) finally insert the filter and make the image. The following text is from the Cokin site:-

How the Cokin System works
The Cokin Creative Filter System consists of three main components:
A filter holder / Adapter ring and a Filter.

1. Screw the adapter ring onto your lens.
2. Slide the filter holder on the adapter ring until it snaps in place. The filter holder is now solidly attached to the lens, yet it can rotate both left and right.
3. Slide the filter into one of the filter holder slots. The one closest to the filter holder housing is the narrowest; it allows the use of round filters with notched edges (polarizer, star filters..). The two central slots are intended for square filters. The outer slot can be used either for an additional filter or for a coupling ring.