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Finetunemoon

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Kevin
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Hello All,

Having got a dslr for Xmas (Sony a37) I've now had around 7months of trial and error with the settings and I'm getting some ok results, I've recently purchased some filters from eBay, only cheap ones for practice, the 2 I'm having difficulty with are the ND filter got a nd2 nd4 and nd8 and was looking to do long exposures, but the photos keep turning out white :( I've been reading online and I see there's an Nd10, is this the maximum and would the 10 differ much from the 8stop? What settings would be best to get a decent long exposure of a cloudy blue sky?

The other is the IR filter, when this turned up I didn't have a clue what to do :) after a bit more search and some playing about I've managed a few shots, which seem very grainy again if you could give me an idea of what settings would work for this filter or some advice that would be great

Cheers

Kevin
 
The ND8 filter only works out as a 3 stop filter, as an example if the shutter speed was 1/250 with no filter then with the ND8 it would become 1/30 so not really slow enough to do much in daylight, it would help at dusk and dark but a lot of photos you see with the smooth water etc are done with a 10 stop filter (this doesn't equate to an ND10)
 
Thanks Martyn

But now I'm even more confused, so what is a 10stop then :bonk:

Cheers
Kev
 
Finetunemoon said:
Thanks Martyn

But now I'm even more confused, so what is a 10stop then :bonk:

Cheers
Kev
Click to expand...

ND filters are marked in different ways - in stops, or filter factor, or optical density. Eg, one stop, or x2, or 0.3 - all the same.

So if you want ten stops, which it sounds like you do, then that would be x2, 4, 8, 16, 32, 64, 128, 256, 512, 1024. In other words, ten stops is x1024 (usually rounded to x1000) or 3.0.

On the IR filter front, that is difficult with a DSLR and results range from very mediocre to hopeless. The best way by far is to get a camera converted for IR use, which basically means removing the IR filter over the sensor so the camera is then unsuitable for normal photography.
 
Last edited:
Finetunemoon said:
Hello All,

I'm having difficulty with are the ND filter got a nd2 nd4 and nd8 and was looking to do long exposures, but the photos keep turning out white :( I've been reading online and I see there's an Nd10, is this the maximum and would the 10 differ much from the 8stop? What settings would be best to get a decent long exposure of a cloudy blue sky?
Click to expand...

But a 10 stopper won't solve the problem of everything being white if you're not setting the exposure correctly. Sounds like you're putting the filter on to cut out a proportion of the light and then using a shutter speed that is way too long to provide the right level of compensation for the light reduction.

With an ND8 - or 3 stops - you should still be able to use auto exposure and possibly autofocus with the filter in place so give this a go. Camera on tripod, ISO at lowest setting, in aperture priority set aperture to f/11 or the like and see what the resulting shutter speed is. Depending on ambient light and the amount of movement this could give you the effect you're after.

The 10 stopper's will allow you to get way longer shutter speeds if that's what you're after - but the 'turning out white' is down to incorrect exposure and not the type of filter you're using.
 
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