[Closed] Can someone tell me about ND filters?

Sorry don't do cheap. You don't want to pollute the light path where possible - some cheap NDs can give a cast.

So Tiffen, Cokin or Formatt are what we've got for a cross section of cameras.

A 0.6 and 0.9 as a bare minimum.

Tiffen not too expensive. We've got a few of these for our GH4s. (M4/3)

I've got that 20mm lens too, nice lens. Use it loads.

OK thanks, a 46mm Tiffen is £25 which is manageable (although they seem to be $17 in the US!)

https://www.amazon.co.uk/Tiffen-46ND9-Neutral-Density-Filter/dp/B000BTYEHA

Would you really recommend against buying just one to begin with? I'd rather just get one to see if I even bother with the extra faff of using them, before investing in multiple..

One is okay. Get the 0.9 then but it will have to be relatively sunny to use it. That's 3 stops but at least it will be less than subtle.

If I'm out on a shoot (video not stills using with GH4) I find myself swapping with .6 and .9 a lot. That's the nature of the best. If you're half serious you will need an array of NDs to cover changing light.

But nothing stopping you starting with one.

Avoid vari-NDs, they're awful. Even £200 ones!

Thanks. You say it will need to be pretty sunny to use a 0.9, is that with a normal shutter speed? Will it be useable with a long exposure (more than 1 second) for sunsets?

Avoid vari-NDs, they're awful. Even £200 ones!

Do you mean graduated ND filters?

No I mean variable ND filters. Effectively two polarisers sandwiched together to block variable amounts of light. Often a cheap / quick way of changing ND filters. They're all pretty rubbish even decent ones (we have some Formatts).

Thanks. You say it will need to be pretty sunny to use a 0.9, is that with a normal shutter speed? Will it be useable with a long exposure (more than 1 second) for sunsets?

Actually fast shutter speeds it will be plenty - im actually in digital cinematography rather than stills and we tend to shoot 1/50 so for you it will be different of course. I think you're going to have to experiment as there are lots of factors. But you won't go too wrong with with a .9 as a start.

Talking about ND Grad filters though - for the sunsets, this is likely what you'll need. Then the fact you've got a couple of filters makes the Cokin system more appealing. The main reason I went Cokin, was due to having 3 lenses with 3 different thread diameters that I wanted the filters to work with.

Yeah Grads are great, but I would say get the basic NDs sorted as they're essential. And actually a kit may be better but OP was looking to get in with minimal spend.

Talking about ND Grad filters though - for the sunsets, this is likely what you'll need

I would prefer just to bracket exposures and blend in photoshop (or whatever) to ensure I got the correct exposure contrast and no risk of border effects.

No I mean variable ND filters. Effectively two polarisers sandwiched together to block variable amounts of light. Often a cheap / quick way of changing ND filters.

Generally a circular polariser and a linear one; the presence of the linear polariser will prevent through-lens auto-focus from working.

Yeah I would tend to favour not baking it in at the neg end. Different ways of doing the same thing.

However there is no substitute for cutting down light with a filter, as long as OP understands what he's buying. All good experimentation.

I would spend a bit more money now myself and get a system. For the micro 4/3 kit I use a Lee Seven5 set up which is a square filter system a bit like the old Cokin P - but much higher quality. Going that route would allow you not only to get some straight ND filters, but also grads - which is what you want for sunsets (and quite a lot of other stuff really).

You might not need a filter at all for stills photography.
Its worth watching Tony Northrup (youtube) on how to get an identical result with no filter. [google - tony northrup nd filter youtube]

His method is to take multiple exposures at relatively long shutter speed (1/6) and then stack and combine in photoshop by using "mean".
So e.g. 18*1/6 sec exposures becomes a 3 second exposure with the bonus of vastly reduced noise.

Exactly the same effect as ND but actually better results.

N.B. This won't work as well with _extremely_ long exposures or in _very_ bright conditions, or with anything involving continuous light streaks, but for "natural" movement in trees, water etc. its great (and free!)

I know some people have a fetish about getting effects "in camera", but for me the expense and hassle of carrying and using filters is a bigger ache than a bit of post processing.

On that basis, I also second the idea of using lightroom (or photoshop for combining multiple exposures) for avoiding carrying ND grads as well.

Knowledge weighs considerably less than stuff in your camera bag.

P.S. For the fetishists mentioned above, note that this method can also be used to combine multiple pictures taken _with_ an ND filter in order to extend the effect and avoid carrying multiple ND filters of increasing value.

for me the expense and hassle of carrying and using filters is a bigger ache than a bit of post processing.

Whereas I'd say the opposite. I abhor post-processing, I don't know what I'm doing and it bores the barnacles off me. Each to their own.

Absolutely, each to their own.
I go out mostly for wildlife photography and will occasionally take landscape pictures if something comes up, so thats where the "hassle" is (buying, carrying and maintaining kit that I'll only use a few times a year).

But its still useful to know that there are methods I can use if I need to.

I agree about post processing. After much faffing over the years most of my post processing is:
Select many similar images in lightroom,
auto-sync on,
change colour temp if necessary,
fix exposure, white and black point (make histogram go all the way across),
maybe poke vibrance and noise,
crop if required, and
done.
(Revisit best images later for tweaking, Sharpen later for export).

its still useful to know that there are methods I can use if I need to.

Totally agree there. If you know a bunch of different ways of achieving a result, you're better equipped to select an appropriate technique for the given situation. And TBH, if there was only one way of doing things we'd all be creating identical photos.

I would absolutely learn different methods. But would never go out without some form of ND to hand.

Likewise post-processing is essential if you want to get the best from your pictures. After all if you're outputting JPEG images you are at the mercy of your cameras P-Ping.

Rone out of interest, have you ever used a ND filter for a portrait? I'm looking back at my catalogue and even shooting wide open at f/1.4 I can't find an image with a shutter speed faster than 1/800s.

I can imagine that if I tried to make a portrait in the glare of the mid-day sun at f/1.4 I might run into the limit of the camera's fastest shutter speed but then I wouldn't ever make a portrait in those circumstances. I can see the need for other work, just not portraiture.

rone will be more experienced than me, but the only reason I can think of is if a particular shutter speed is a priority.
I've done a portrait where I wanted a tube train to have motion blur behind the subject.
I've also messed about on roundabouts, etc to get motion blurred backgrounds. You might also want traffic, walkers, etc blurred. Basically to replace lens bokeh with motion blur.

Obviously you run the risk of the subject being blurred too if not too careful.

Yeah you're right under those circumstances.

I'm a shooter for film production and we use 1/50 so we have to use ND to get the SDOF. (I thought the OP was into shooting the sun - which you've got be blocking light for.) So his exposure will be at the other end of the scale.

I'm not a stills expert at all but there is a cross-over. The shutter-speed changes everything.