I recently got a 10-stop ND filter and wanted to share some tips about shooting with it. As time goes by and I gain more experience or get more hints from other people, I'll re-open this page and add to it. Check the version number here to see if there's new information you haven't yet read.
This is the initial post, version 1.0 on September 27, 2011
Updated: October 3, 2011 (bottom of post)
Background:
I had a variable (up to 10 stops) ND filter that I was really unhappy with. Not only was it extremely unsharp but also it generated a terrible interference pattern when used with my wide angle lens. The concept is interesting, because you can screw it onto the lens and change exposures just by rotating it, so you could focus, meter, compose, etc., then spin it. But the results were just too unacceptable. There are better brands available: Singh-Ray and Fader are well-thought of (the former apparently is clearly better, but pricey). But I realized that there was no real reason to use in-between values, like 6-stops or 7-stops, so I might as well go whole hog and get the 10-stop filter.
I bought a B&W brand filter made in Germany, and you can get it at B&H Photo —
click here to access the page in their online store. This link takes you to the 77mm single coated version, you can find different sizes from there. The first thing you realize when you pick up this filter is that the build quality is superb. It's heavier than most other filters that I've had, for example.
There are a number of tutorials around. One of them is by Scott Kelby and there's a YouTube video
here. If you're reading this on an iPad, I'm sorry but it's in Flash so you may not be able to view it. As usual, Scott gets quickly right to the point and his tutorial is great, but if you're new to using these filters, you may want a bit more information, so here goes!
There's LOTS to think about!
Here's what you can do with the filter, shooting fast water in the middle of the day:
Before:
This was shot without the filter. The exposure was 1/30 sec at f/11, ISO 100. The lens was the Nikkor 70-200mm f/2.8, set at 70mm.
After:
Exactly the same setup, except the filter was screwed on the lens. The shutter speed was now 61 seconds (I was trying for 1 minute!). This was in the middle of the day and the sun was shining brightly, by the way!
One thing you have to realize when you shoot these kind of shots: It's not like your usual digital experience: you know, we live in a world where people complain about how long it takes to heat something up in a microwave oven! This is more like the old days, where you have to consider carefully what you're doing and go through a whole bunch of steps and a mental checklist to capture an image. It will probably take you 5 or 10 minutes just to set up the shot!
For those of you who remember the old days: essentially what you're going to do is set it up, compose it, take a few "Polaroids" to make sure you got it right, then finally do your image. If you're shooting long dawn or dusk shots, it could be 2 hours before you're done with just ONE shot — so make sure everything is right so you don't waste your entire time!
What you need:
- Your camera, with a fresh battery and suitable memory card
- A sturdy tripod
- A cable release, preferably with a locking button
- Your Neutral Density filter
- Something to cover the viewfinder eyepiece to keep light from leaking in.
That last one is important (well, they all are!). Normally, your eye is blocking the viewfinder and of course exposures are shorter. Scott mentions gaffer's tape, which I don't like because I don't like leaving sticky residue on the camera. I usually just throw an opaque cloth over the camera, folded a few times. Brings back the old days shooting under the hood with a 4x5!
Remember also that holding the shutter open takes battery power. Don't run out in the middle, and if you have a Nikon with noise reduction, you'll have to keep it powered up for twice the length of the exposure.
If it's windy, even a dangling camera strap can move the camera too much. Weight your tripod if you can. Do it right — you're investing a lot of time to make it right!
Composition is up to you, but you need to think about how much of your image contains moving things (water, clouds in the sky...) and what's not moving (rocks, structures, old shipwrecks). There might be stuff that is moving that you didn't think about, such as trees, branches, leaves, grass, people... I like to try to think about the fixed, motionless things first and remember that anything that is moving is going to be soft and out of focus so it can't be the 'subject' of your image.
Set everything up without the filter.
Focus carefully, then switch your camera to manual focus — your autofocus won't work through the filter, so the camera will hunt back and forth and maybe never find the right focus setting.
Take some
test shots at the aperture you will be using to evaluate the depth of field. Use
Aperture-Priority. Also find the
right exposure for your shot. The metered setting may not be right. Note what the shutter speed is. You will need this for your starting point.
Most modern DSLR's are set up to default to 1/3 stop per click. Assuming you haven't changed this, you will need to click 30 times when you put the filter on. That can be any combination of stopping down the aperture, decreasing the ISO and lengthening the time the shutter is open.
30 clicks. Learn to count to 30 and try not to go the wrong way!
I find myself trying to calculate all this stuff in my head. Taxing for this tired old brain, even though I'm used to using the left half a lot! To make life easier for you, maybe this little "cheat sheet" will help. I created a .pdf file for you to download and print, it fits on both sides of a 3x5 file card which you can laminate and put in your bag. I did it in Excel, so you can also download the original spreadsheet and modify it for your own preferences.
Now carefully spin the ND filter onto your lens. I remove any other filters — skylight, UV, polarizing — the more glass hanging on the front of your lens the more distortion, reflections, etc. can creep in. Once it's on, you can't look through it any more so make sure everything is set the way you want.
Checklist:
- Focus (where you want it and on manual mode)
- Exposure mode: MANUAL
- Aperture set to the opening you want to use
- Shutter speed. Use 'bulb' and a timer like a stopwatch if it's over 30 seconds
- VR OFF if you're on the tripod (the new VR-II is supposed to be better, but why introduce hunting if you don't have to?)
- Exposure compensation and bracketing off
- Shutter release: use "mirror-up" or "self-timer" and a cable release to minimize any camera shake
- Block the viewfinder to keep light from leaking in
- Long Exposure Noise Reduction ON.
Now shoot your image. Be prepared to wait for the Noise Reduction process to complete (if you have a Nikon. Not sure how Canon does it). This should take the same amount of time as your initial exposure.
Great! I hope you get some outstanding images! You may find that you have to color correct them (long exposures turn things blue) or tweak exposures in LR or PS.
You have not used the optimum exposure values for the fixed, non-moving components in your image. You may want to shoot them separately and merge images for the best results. In this picture, I took 5 bracketed shots without the filter, then I merged them to HDR (using Photomatix Pro), tweaked and corrected them, then I imported the long exposure image as a fresh layer, and carefully masked the layers manually.
Update: October 3, 2011
I had a disappointing couple of days in Algonquin Park this weekend, focusing on using my ND filter. I learned a few things (for I am but a grasshopper...).
- I said it in my original post but I guess I didn't take it to heart: you can't use the water or any of the moving things in the image as the focal point of the image. They only enhance the composition that is already there.
My friend Dr. Ron put it succinctly and really well: you need to have something in the foreground which is sharp and not moving. The above shot is a great example of that, somewhat by accident, though. Don't just shoot fast flowing water, it's meaningless.
Long exposures and milky, silky water isn't for every shot. For instance, a really fast waterfall probably looks better with much shorter exposures because you wipe out any vestiges of detail with a long exposure. Also the transition between water and fixed portions of the image have to look natural, or else it looks like you just snipped and pasted it together. Here's an example (look where the rock meets the water)
By the way, long ND exposures do interesting things to the sky as well. I copied and flipped the sky and pasted it at low opacity into the water.
- Don't skip the test exposures.
Your meter may or may not give you a proper starting exposure, depending on the settings, the lighting, the effects you're looking for. Shoot without the filter, find your starting exposure and calculate from there.
- Don't forget to switch all the stuff off that you have to on the camera.
More than once, I found that I forgot to switch to manual focus, and once I had 5-shot bracketing selected. Stop and think!
- The "cheat" sheet I created above is invaluable.
Counting clicks sucks. Especially if you also want to change apertures or ISO.
<end of update #1>
Drop me a line if you have any other comments or suggestions (or comment here). I'd love to see your results. If you found this useful and you feel like contributing to my lens fund (!), every little bit helps! I'm trying to spend more time and resources on these blogs and your encouragement will really help.
