Long exposure

[veros222]

Hi there guys,
I've been experimenting with long exposure shots lately. I have Hoya nd400 for my 50mm prime lens. I'm very happy with it. Here's an example:


My question is as follows. I'd like to get a neutral density filter for my wide angle sigma which uses a 77mm filter. I'm considering the B+W nd1000 filter. Can anyone tell me what the difference would be between a 400 and 1000nd filter, technically wise and what effect will it have on the images compared to nd400.

Thanks a lot in advance.

[OsmosisStudios]

The ND400 is a 9-stop ND filter; the 1000 is a 10-stop. You can DOUBLE your shutterspeed with that.

I don't know why you wouldnt have gotten a 77mm filter in the first place and simply gotten step-up rings.

[veros222]

Because I just got my new sigma lens about two weeks ago.

[OsmosisStudios]

Originally Posted by veros222

Because I just got my new sigma lens about two weeks ago.

I always try to buy the largest size (77mm) and simply get step-up rings for each size I may need. Regardless of what lens I have.

[dcclark]

Those are both very serious light-stoppers. I love the effect of the very long exposure in your sample photo -- so if you're planning on keeping that sort of thing up, go for the strongest ND filter you can (the ND1000, probably).

[navcom]

Another option is a variable ND filter. I've used one for some time and it makes long exposures extremely easy...no guesswork. Just set your aperture for the depth of field you want and dial in the ND till you get the shutter speed you need.

[mad editor]

Originally Posted by OsmosisStudios

I always try to buy the largest size (77mm) and simply get step-up rings for each size I may need. Regardless of what lens I have.

That's a very good idea! Thanks,

[veros222]

Thanks everyone. One more thing. Is is a step up or step down ring I should get. I looked into it and it's quite confusing.

[dcclark]

It's almost always called a step-UP ring, as in, you're stepping the lens's filter ring up to a larger size. They usually will be written as "72mm to 77mm step-up ring", meaning, it converts a 72mm filter size, to a 77mm filter size.

You generally don't want to step DOWN, because then you could start seeing the filter ring in your images -- not good.

Here's an example at Adorama.