Using graduated filters - what's your technique?

[newmoon2night]

I'm fairly new to LF and am having trouble seeing where to position my graduated ND filters (viewing through the ground glass).
Last week I sat by a pond for half an hour in sub zero temperatures, waiting for the right moment, got the transparency back yesterday and am really pleased ...except I think the grad should have been slightly lower (where the sky met the land). So it's time to sort this out!
I use Lee filters, and have possibly made a mistake in buying soft rather than hard graduated filters ... I'm suspecting that most people opt for hard because it's easier to see the 'join'.
I've tried putting a piece of paper on the filter, aligned to the area where the filter graduates, but am really having trouble seeing the paper accurately through the ground glass.
A friend suggested buying a bright orange graduated filter and using that as a measuring device.
Before spending any more money, is there a generally accepted practical technique that works please? Thanks.

[Justin Black]

The hard edge grads are indeed easier to position, but with practice, soft filters can be handled easily too. My approach is to stop the lens down to the aperture at which I plan to shoot, and gently slide the filter up and down and rotate it back and forth until it appears to be in the right position. That's about it. A good dark cloth really helps.

[anchored]

Hard edge grads my indeed be easier to position, but I rarely (really just about never) use them. If you use a wide angle lens and small aperture the dividing line shows up harshly in the image. The only time I use hard edge filters is for shots with a clearly defined horizon with nothing sticking above.

I use Lee, Singh Ray. and HiTech filters. If you are wanting to use hard edge filters, you might consider using HiTech hard edge grads instead of Lee's (I have both). You'll find the HiTech hard edge grads are a bit softer on the transition than Lee's.

As for placing... you're right... they are a bit hard to place the transition accurately on the soft edge filters. Since I've screwed up a few shots by placing the filter too far down, I have a tendency towards keeping the transition a bit further up than at first I feel it should be. As for "technique"... since the transition is so hard to see on the GG, I simply look at the placement of the grad in reference to the holder and "eyeball" it's placement.

Glenn

[Eugene van der Merwe]

I find myself using hard grads far more often than soft ones, and the soft ones do make seeing the start of the graduation much more difficult. I agree with jason about stopping the lens down for final positioning, the graduation gets a bit more defined at smaller apertures and may appear to shift a little as you stop down, particularly with shorter lenses. Practicing by viewing a brightly lit, white wall while adjusting the filters, may help you get a better feel for how to position them. Good Luck!

[vinny]

stopping the lens down is a must. were you using black paper? get some black construction paper an fold it over the top of the filter where you want the line to be. make one for each filter. almost foolproof.

[newmoon2night]

I haven't been stopping down the lens to view the filter, so I'll do that from now on.

I tried some white card initially, and then some red card. I'll try black next.

I'll also do some practicing against a white background - that's a good idea.


stopping the lens down is a must. were you using black paper? get some black construction paper an fold it over the top of the filter where you want the line to be. make one for each filter. almost foolproof.

[Darren H]

I have used an old cheap red Cokin filter to see the line but diffraction (I think) make the line less hard edged than I would like. So it helps some but not enough.

For a soft edge I use the above mentioned eyeball method. As a soft edge it is less important for exact placement.

For the hard edge I stop down to at least f/11 and the jiggle it to help see it. My 2stop and 3stop hard edge seem to be fairly easy to spot.

[timparkin]

The hardness of the edge is affected by a couple of things, one of the main ones is the distance from the nodal point of the lens to the filter.. Some filtermounts and lenses mean that the filter ends up a long way away from the nodal point and hence the result is a harder edge. In some SLR designs, (canon 16-35 for example) the nodal point is right next to the filter and it's very wide; this ends up with a softer edge.

I'm presuming that if you are working close up, the graduation will get softer also (you are only using a portion of the available circle).

Personally I very rarely use soft graduateds but having moved to large format only recently and using Velvia 50 a lot, those small amounts of density make a big difference so I may use soft more often.

As a final note, Lee make a standard hood with a slot at the front of the hood. In this case the filter is a long way away from the nodal point and hence will be a very hard line..

I hope I got that all the right way around :-)

Tim

[Justin Black]

I forgot to mention that a handy substitute for a grad is a matte black card that can be used in front of the lens to dodge highlights during longer exposures of, say, two seconds or more. That's how I made the attached image, which required a twelve second exposure for the foreground, but only two seconds for the sky:

[Mark Carney]

Vinny

Thats brilliant. I can never get the line right with the soft grads and my eyes are getting worse. The construction paper will be great.

[ljb0904]

Hmm, I'll have to try the matt black card.

I mostly guess and don't worry to much with the soft grads. Hard grads I place, stop down almost as far as the lens will go, rotate the grad in the holder and reposition. It's easier to see the transition if you rotate the grad.

[QT Luong]

Justin's tip could be handy in a situation where GNDs are difficult to use (such as extreme wide angles or shooting into the sun), but how can you position accurately the transition when using a card ?

[Justin Black]

Justin's tip could be handy in a situation where GNDs are difficult to use (such as extreme wide angles or shooting into the sun), but how can you position accurately the transition when using a card ?

That is a really good question, and sorry that I didn't describe the technique in greater detail. Basically, I stop the lens down to shooting aperture, look at the ground glass, and position the black card at the bottom of the part of the composition that I want to dodge. Then I hold it in place against the front of the lens, pull my head out from under the dark cloth, and look at it to see where it falls in relation to the lens itself. Then meter the exposure and decide how long the dodge for the bright part of the scene will be relative to the exposure for the dark part. Start the exposure, dodging with the card in front of the lens and counting down the seconds. Pull the card away to allow the necessary time for exposure of the bright part of the scene. Close shutter. That's it.

It takes a little bit of practice to get this right, but it is really much easier to pull off well than it might sound. Unfortunately, it doesn't really deal with the potential benefit that Tuan mentions with regard to eliminating the need for a grad filter when shooting into the sun, because if you're shooting into the sun, your exposure would be too short to use this technique.

[newmoon2night]

Justin. That is a really good idea - thanks, and I was wondering what your technique was also, and had thought that maybe you were using multiple exposures.

I was scratching my head wondering what construction paper was! A quick search on Wikipedia and I see its sugar paper, which I think is the name used in the UK. My wife's an artist so I'm pretty certain there'll be some readily available.


That is a really good question, and sorry that I didn't describe the technique in greater detail. Basically, I stop the lens down to shooting aperture, look at the ground glass, and position the black card at the bottom of the part of the composition that I want to dodge. Then I hold it in place against the front of the lens, pull my head out from under the dark cloth, and look at it to see where it falls in relation to the lens itself. Then meter the exposure and decide how long the dodge for the bright part of the scene will be relative to the exposure for the dark part. Start the exposure, dodging with the card in front of the lens and counting down the seconds. Pull the card away to allow the necessary time for exposure of the bright part of the scene. Close shutter. That's it.

It takes a little bit of practice to get this right, but it is really much easier to pull off well than it might sound. Unfortunately, it doesn't really deal with the potential benefit that Tuan mentions with regard to eliminating the need for a grad filter when shooting into the sun, because if you're shooting into the sun, your exposure would be too short to use this technique.

[lostcoyote]

in a pinch, you can use your sheet film slider... but you have to be careful that it doesn't reflect light if held at the wrong angle. most of my slides have a dull black finish.

you can use your own eyes and line of sight with respect to the subject line, the lens, and the displayed image to determine where to hold the filter as well.

i sorta made a crude diagram. the lower image shows a 50/50 split between bright and dark areas (red is say, 2 stops brighter and the camera is positioned so that the bright and dark areas cover 50/50 film area as well. the slide is positioned 1/2 way across the lens to dodge thge bright area... say, the sky.

in the upper diagram, (sorry, i didn't get the black lines drawn in) i tried to show a diagram of the camera pointing down so that the bright area is only 25% of the image area. of course, when doing this, you might tilt the film plane backwards to keep it parallel with the object and secure the focal plane depth of field/focus... but if you draw a line between red and green splits, intersecting the lens center point, you can see the card gets placed higher up on the lens 25% down from the top of the lens.

this imaginary line of sight (hand-drawn red line) is shown in the third diagram and holds for all camera/lens orientations with respect to the subject and the image displayed on the ground glass.