UKC

Can anyone recommend/advise whose ND Filters to go for e.g Kokin, Hoya, Tiffen. Nothing too expensive at this stage as i'm just getting into photography (in a way other than point and press). If it helps they are for a Nikon D40X

In reply to Andy Hudson:
bump

In reply to Andy Hudson:

Sorry, can't speak from personal experience. But from what I've read

- Cokin ND filters have a bit of a reputation for having colour casts
- Hoya are probably fine

I'm not sure where HiTech come in price-wise but they are probably cheaper than Lee and if they're good enough for the likes of Ian Cameron...

In reply to Andy Hudson:

tangent alert...

I've never understood why ND filtering can't be done in-camera on digital cameras by varying the gain row-by-row and/or varying the exposure row-by-row. There would be an associated firmware and software development cost so it would be tailored toward the slightly higher end. I suppose HDR has circumvented the need and opened other creative avenues, but with electronic ND filtering you'd only have to take one shot for those standard ND scenarios

In reply to Andy Hudson:
Go for the cheapest you can get hold of then, any colour casts can be easily sorted out later with digital. (It was always over exaggerated anyway).

In reply to Blue Straggler:

it is, thats what programmable ISO is, just you can only turn the gain down so far. as for gradient filtering (which i think you go on to describe) that would be an idea but it would depent on the sensor allowing the gain to be altered for different rows (or done as an in camera post process, which would be limited given the limited dynamic range of the sensor hence)

In reply to Andy Hudson:
for a cheap and cheerful theres always DX http://www.dealextreme.com/details.dx/sku.23337~r.92395607 I have one of them, yes it has a slight colour cast (which can easily be accounted for) and probs not the best quality, but for what I use it for it suits me.

In reply to sm1thson:

Sorry, I got grad filtering confused with ND filtering there.

that would be an idea but it would depent on the sensor allowing the gain to be altered for different rows (or done as an in camera post process, which would be limited given the limited dynamic range of the sensor hence)

I didn't mean post-capture in the camera, I meant pre-capture. As you say, post-capture relies on the dynamic range of the sensor; the whole point of ND filtering is to overcome such a limitation.


Anyway that's enough speculative tangent Ta.

In reply to Blue Straggler:
>I didn't mean post-capture in the camera, I meant pre-capture

In the pro audio world, you have compressors and limiters. If the signal exceeds a set threshold, you attenuate the signal by a user defined ratio eg: 4:1. So 4 input units above your threshold equals 1 output unit. (You use them to stop short loud bits from overloading the system).
I don't see why this couldn't be done in camera, apart from the cpu requirements. I think Canon have something similar with their "highlight tone priority" feature, but not on a per pixel basis. Of course setting it so that it attenuated a stray sunbeam, but not a reflection in someones eye, may be tricky.

In reply to Andy Hudson: Whats your main subject matter ? I would always encourage ppl to buy lee filters though.

I'd buy Cokin and IF you notice any colour casts just change it in photoshop. Lee filters are very expensive.


RE: Why you're still having to use ND filters

Theres a couple of reasons why you can't keep turning the ISO down, one is that the higher the base ISO the better the high ISO's are and that's usually what people complain about. Going down below the base ISO usually starts making things worse (Look at the D3s, 200 (the base ISO) is better than 100). In the same way that you're amplifying the signal to get high ISO, you're doing the opposite to get the lower than base ISOs.

If you're really into long exposures buy a Kodak Pro SLR/n, the ISO goes down to about 12 or something daft.

In reply to Richard Carter:


<hijack> Noob question here, but how do you know what the base ISO is? I've just got a D5000 and IIRC, from 200, it goes to L0.3...etc. Does that mean 200 is my base ISO? </hijack>

In reply to Fraser:

It's probable that the 200 is your base, the base iso on my D300 is 200 but the reputed 'sweet' spot is 0.3.

In reply to Removed User:

Thanks.

In reply to Andy Hudson: Hitech filters are very good and have little to no colour cast even when stacking 2-3 filters on top of each other. I got mine from the place below, good price.

http://www.teamworkphoto.com/index.php?main_page=index&manufacturers_id...

Duncan