Page 1 of 1

ND Grads

Posted: 21 Jun 2022, 18:44
by Oscar
In another thread I mentioned that I've previously had issues with overcast skies ending up blown-out, so I've been taking advantage of this week's weather to experiment with ND grads. To test, I shot an overcast (urban) landscape with no filter, 1.5 stops, 2.5 stops, and 4 stops of ND grad to get a feel for how much is "enough". Obviously that's a matter of taste and conditions, but it's good to know what to expect next time I'm out doing a proper shoot.

I've only scanned these negatives so far; I've run out of paper developer until Friday, so I'll print them on the weekend to better assess the results.

My current setup uses screw-in adaptors into the lens onto which is clipped the filter holder. Into the filter holder one can slide one or more 150mm filters.

So my question is, is it just me, or are ND grads all a bit of a pain to use? The results are good, but maybe there's a better way to get good results in-camera. Has anyone had any luck just hand-holding the filters perhaps?

Is there a better way or should I just harden up and get better at using what I've got? :)

Re: ND Grads

Posted: 22 Jun 2022, 14:26
by Barry Kirsten
Hi Oscar, I've pondered at times trying ND grads but so far haven't got around to it. I'm looking forward to seeing the results of your tests. I usually use contrast filters/polarizers, and printing controls, but admit there are often times when a ND grad would make life easier. Good on you for trying it out.

Re: ND Grads

Posted: 22 Jun 2022, 18:06
by Oscar
Hi Barry,

I won't post these test results because they show too much info about my house :) But I might re-do them differently soon and I'll post those. In this test I carefully metered for incident light falling on the scene, but forgot to measure the exposure difference between foreground and sky, oops.

Looks like the 1 stop ND grad is good for fairly minor tweaks, but a brighter overcast sky needs at least 2 stops, possibly more depending on the intent of the shot. So I might buy a 3 stop ND grad soon. Some brands are very expensive though!

I'm sure all the above is common knowledge for experienced landscape photographers, but until now I haven't done much in that realm, I'm hoping to do more soon.

One thing that caught me out was the ND grad filter values. I bought my filters online a couple of years back, but I'm pretty sure they're not the density I thought they were. For example, what I thought was a 2.5 stop ND grad is actually 1.6 stops. (Verified by comparing spot meter readings of a fixed tone both with and without the filter).

Re: ND Grads

Posted: 23 Jun 2022, 10:43
by Maris
ND grads can be a bit of a deep ocean. I have used "hard" and "soft" grads up to 2 stops in strength. The hard grads are ok for skies above a straight sea horizon and the soft grads for irregular land horizons. But it is a task of judgement to avoid the results looking artificial. Checking the effect of the ND grad with the lens stopped down to shooting aperture helps visualise the result.

An alternative technique with straight horizons and a tripod mounted camera is to slide a card into the filter holder and blank out the sky. First exposure is for the land. Then pull the card and the second exposure is for the sky. Tricky to get right.

In recent years I've practiced subtle burning in of blank skies to give a trace of tone in gelatin-silver printing. If I get it wrong I can re-print. The grad NDs hardly get used because their effect is permanently on the negative and difficult to undo if wrong.

The grad filter I use most in B&W work is a grad RED which darkens blue skies, makes the clouds pop a bit, but does not darken shadows at ground level.

Re: ND Grads

Posted: 23 Jun 2022, 12:41
by Oscar
Hi Maris,

Thanks for the great tips! I'll have to give some of those a try soon, especially the idea of blanking the two halfs and exposing twice.