Neutral Density Filters

http://www.filterdepot.co.uk/index.php?cPath=54_57

The above link is to a site where I want to order a set of 3 ND Grad Cokin Filters (ND2, ND4 & ND in the 'P' series, only trouble is I am confused as to which ND8 I should order as there seems to be three ND8's to choose from
does anyone have an idea or cd clarify for me please?

Mucho gracias, Lilly

I can't tell you why there are three, but ND grads are usually described as 'hard' or 'soft'. This is not a comment on the material used but the transition between grey and transparent. The soft ND grads have a much less defined change between the two. In hard grads, the transition is much more abrupt.

Looking at the Cokin site www.cokin.com, I'd say the P-121 is the normal Hard ND8 Grad, The P-121S is the soft transition variant, and the P-121F is maybe 'Fine'. The P-121F certainly appears to have a very gradual change from grey at the top to transparent at the bottom.

If you take a look at the Cokin site, they show the effect that each filter has on a scene.

HTH.

Rregards,

Thanks Peter, Cokin site takes a bit of digging around but got there in the end.
For anyone else interested in this subject, I found this helpful .pdf doc on just the Neutral Density Cokin Filters.

http://www.cokin.co.uk/pdf/COKIN%20ND%20Chart.pdf

Hi Lilly
The following may be useful in helping make a decision as to which sort you need from FORMATT web-site (Hitech filters):
http://www.formatt.co.uk/stills-filters/filter-kits/graduated/grad-kit-4-nd0-3-n...

"Graduated NDs are available in Soft Edge or Hard Edge varieties. Soft edge grads have a smooth transition from clear to ND. Hard edge grads have a more defined hard lined transition and should be used for longer lenses. For extremely long focal lengths a razor edge grad providing a very highly defined transition, may be ordered."

The 85mm size fit in the COKIN 'P' holder
Hope this helps

Andy

When I look at some different websites about ND grad filters they claim that "cheap" filters like the Cokin filters are not actually Neutral Density but that they let the red blow out a little.
How are the experiences here with different ND and ND grad filters?

My past experience using a 2stop Cokin grey-grad with film, made the 'grey' sky look slightly pink!

Andy

I've used Cokin P and HiTech P-sized.
Both tend to accentuate red/magenta - especially if you stack two or more filters.

I now have Cokin Z-Pro sized and they are much better than the P-series. However, there is still a very faint tinge of red when stacking two. I understand that the Lee filters don't suffer from that.

But, as I've said before, the Z-Pro filters are delicate and very easy to get marks and scratches on. I've already scuffed £45 worth of filters But I can live with the marks... they generally don't get in the way. (I've heard the Lee's are harder... but of course they are probably THE most expensive!!)

Actually, for some images the red tinge helps somewhat And of course you can always Photoshop it out very quickly and easily

Matt