Need some ND filter advice.

Hi Guys,

thinking about getting myself an ND filter kit... something like this one

But im a little lost, Iv read a few things about venyetting if I get the wrong type etc. Can anyone confirm this?

BTW, im a 5dmk2 user and the filters would be used on a 17-40L and a 24mm prime. Both are 77mm lenses.

That kit gives you a good set of ND filters and is a good bang for the bucks. You might experience some vignetting with the 17-40 at the wide end. Maybe not. However, Cokin makes a wide-angle holder specifically for this problem:

http://www.adorama.com​/CKBPPW.html

I couldn't find it on that Cameraworld website you linked to, but you should be able to buy it elsewhere in the UK, I should think. I have tried the holder on ultra-wide lenses (for example, a full-frame equivalent of 18mm) and had no vignetting. Note that you cannot stack the filters, but with that kit you have a good selection without resorting to stacking anyway.

I think Cokin products are hard to find nowadays because I think they were recently bought by some other company. But after awhile it seems their products will be more readily available.

first, its a GND (graduated set) rather than ND Neutral density set. I know the website also calls it Nd, adding graduated later. Second, you do not want the P size for your set up, you need the Z size for the 17-40 on 5d2. third, Cokin filter quality is not that great with a stronger Magenta cast. If you are a stickler about image quality, look at Lee filters or the cheaper Hitech filters. fourth, the ND2, or one stop is pretty much useless. I would start out with just a 2 stop soft GND, and see how things work out. good luck.

cheers for the advice guys, plenty helpfull!

I use a different approach. I take a bracketed pair of shots and merge them in PSE or PS5 so that my final image had the full range of light. If I were to use a GND, I would be not capture the full range of light. Depending on the scene I might take 3 or more shots with the intent of putting them together in HDR Efex Pro. That product lets you select the way the final image looks....from heavy grunge...to smooth transitions.

I do use a VND for shooting moving water. The VND lets me dial in just enough loss to smooth out the water.

So in my bag, CPL and VND are the only filters I routinely carry. But, that is my approach. Each to his/her own.

kevindar wrote in post #13150082
first, its a GND (graduated set) rather than ND Neutral density set. I know the website also calls it Nd, adding graduated later. Second, you do not want the P size for your set up, you need the Z size for the 17-40 on 5d2.

Yes, as you say, the kit has graduated filters. He doesn't say if that is what he is looking for or not, but you do need to be careful with this stuff.

I'm wondering why you think that the Cokin P system will not work with a lens with a 77mm diameter. Their specs say it should work with "48mm-82mm filter sizes." I know that 77 is getting pretty close to that limit, but I have used the A system with lenses that are pushing its limit and not had a problem. I just recently acquired a Tokina 12-24 lens that has a 77mm diameter and was hoping to use my Cokin P system with it, so I have a good reason for asking!

5d2, 17mm, p system = severe vignetting/blocking.

kevindar wrote in post #13150246
5d2, 17mm, p system = severe vignetting/blocking.

I use the P system with my 10-22, no severe vignetting.

However, I do agree it is better to go for a larger system.

kevindar wrote in post #13150082
third, Cokin filter quality is not that great with a stronger Magenta cast. If you are a stickler about image quality, look at Lee filters or the cheaper Hitech filters.

I tried a Hitech ND last year, and even though the helpful folks at 2filter said it would be color neutral, I got an unacceptable-to-me magenta color cast. I can only imagine how poorly the cheaper Cokin filters would perform. To my knowledge Lee and Singh Ray are the only mfgrs that make truly-neutral nd and gnd resin filters. They're really expensive (Singh Ray) or difficult to find in-stock (Lee), but they are very reliable. I am not enthused about putting a cheap color-casting filter over my expensive lenses, so I prefer to either use none or use the best. In my view there is no place for low or medium quality filters.

The 4"x6" size is also preferred, not only to adequately cover the wide-angle lenses (like 17mm), but also provides ample surface area for handling.

Can I ask fro recommendation on ND filter strength? I've read the sticky post, guide to ND filters but still unsure what strength to get. I want a 58mm for the 18 - 55 kit lens, to get good silky blur effect on water - rivers, waterfalls, beaches. I'm assuming I need to go up to 4 or 6 seconds exposure max to get a good blur?
So if I'm typically looking at 1/125 at F8 for example, I'm going to need a 9 stop filter to get it dark enough to allow 4 second exposure - right? Do they sell 9 stop ND filters? What's the most popular number of stops for waterfalls and (subdued lighting) beaches?

al heeley wrote in post #13165075
Can I ask fro recommendation on ND filter strength? I've read the sticky post, guide to ND filters but still unsure what strength to get. I want a 58mm for the 18 - 55 kit lens, to get good silky blur effect on water - rivers, waterfalls, beaches. I'm assuming I need to go up to 4 or 6 seconds exposure max to get a good blur?
So if I'm typically looking at 1/125 at F8 for example, I'm going to need a 9 stop filter to get it dark enough to allow 4 second exposure - right? Do they sell 9 stop ND filters? What's the most popular number of stops for waterfalls and (subdued lighting) beaches?

You can get water motion blur from about 1/30 on... and at much over 2 second it can look more like fog than water, depending upon how fast it's moving, but that might be what you are looking to achieve.

Consider using several weaker filters, so you have some control over it. With several filters of different strengths, you can either use them singly or stack two or more to increase the loss of light, meeting more different situatiosn.

There are also variable ND filters, that work a lot like a polarizer... you turn them to increase the strength of the filter. They range between 2 and 8 stops of light. Here's an example (I haven't used so can't say anything about quality... there are much more expensive ones, too.)

The really strong filters are often used by videographers, might be overkill for you, and could be too strong in anything less than high sun. Video is limited to an effective shutter speed of around 1/50, so often relatively strong ND filters are necessary if they're going for a shallow DOF effect in daylight.

Depending upon the scene you are shooting, you also might want to use in combination with a Circular Polarizer, which loses up to 1.3 stops itself. Take that into consideration.

Someone mentions color casts, and yes that's a concern with cheaper filters. However, it's also often easily fixed either in post processing or by setting a custom white balance at the time you are shooting.

I use the Cokin P system for some things... It's good for rarely used filters that you don't want to spend a lot of money on, or when you want to experiment with several different inexpensively, to try to determine what you will find most useful before you invest in better filters for the long run. As a side note, I have used P series on 17mm lens (older Canon 17-35/2.8L to be specific, which has 77mm filter threads same as 17-40/4L) without any vignetting problems. However, the Cokin holder I have for wide lens use has been modified so that it only has a single filter slot, making it less likely to vignette.

Also, there are many manufacturers making all sorts of filters and other accessories to fit the Cokin holders. Lee, Singh-Ray, Tiffen and others make quality rectangular filters to fit different Cokin size holders. Adorama sells some house brand that's even cheaper to experiment with, than the Cokin filters. Lee makes a bellows type hood to fit them, too. Note that Cokin itself is currently in bankruptcy... Might effect availability of some items for now or in the immediate future. However I would bet that someone will pick up the company and restart it. And the system has been around so long that it's pretty easy to find stuff, still.

Thanks Alan - informative post. I have a CPL so maybe getting an ND9 is overkill for me to start playing with. I like playing with everything in photoshop anyway so colour casts and cheaper filters is not an issue with me.