The following are some of the practical aspects of choosing and using ND filters. This will hopefully be accompanied by a more in depth print article, but for now, here’s a summary!
What are they?
- Dark glass (or resin) which allow a photographer to lengthen the shutter speed.
- Screw on (circular) vs Square (slot in) – see below in accessories
- Light blocking terminology:
|Stops blocked||1 stop||2 stop||3 stop||10 stop|
|No filter = 1 sec||2sec||4sec||8sec||1024sec|
- Tripod : MUST be firm and steady
- Cable release : essential to achieve exposures of greater than 30 seconds. Some firmware changes such as ‘magic lantern’ and some camera applications (such as for the sony A7r series) offer an alternative to a cable release but I prefer the former.
- Filter holder and square filter set up. Allows 2(Lee default) to 3(Nisi default) filters to be stacked in front of the camera. Lee requires an additional slot for a 105mm CPL, Nisi system has a CPL attached to the default sized adaptor ring itself. Insert ND filter on the closest filter slot with padding firm against edges of the holder to prevent light leak.
- Screw on filters need no filter kit. Minimises light leak but unable to ‘stack’ with other filters. Can be used with CPL but could lead to vignetting.
- Optical view finder cover (to prevent more light leak). Can be on the camera strap itself (canon) or can be anything invented ! eg. Blue-tac, duct tape.
Density recommendations (approximate)
- 2-3 stop : for waterfalls, seascapes in bright light : target shutter 0.5-5 seconds
- 6 stop : for fast moving clouds, seascapes in low light: target shutter 5-60-seconds
- 10 stop: for elimination of water textures, slowish clouds: target shutter 1-5 minutes
- 15 stop: same target as 10 stop except in brighter conditions: target shutter 1-20 minutes
- Vari-ND: limited by screw on setup and some brands have bad cross polarisation artefact.
Camera setup :
- Turn off long exposure noise reduction. (noise reduce in post processing)
- Turn off autofocus . Leaving it on may result in the camera hunting in the dark for and lead to an out of focus image
- Keep iso low. This is within camera limitations. I like to keep iso <400. (if going much higher, could you just achieve the same results with camera settings alone or less dense ND filter?)
- Activate expanded iso (eg. Iso50 for canon users)
- Adjust aperture according to given scene. At your lens’s sweet spot at f8, the exposure may not be long enough after minimising iso and placing your densest ND filter.
- Usual rules of composition apply
- ND filters allow simplification of ‘chaotic’ elements eg random water motion, unattractive clouds. Use these to emphasise areas of detail within your image
- Compose without ND filter on to achieve your desired composition and to find your focal point manually.
- Don’t let the ND filter dictate the shutter speed. Use ND filters to achieve the shutter speed you desire for the scene.
- For every stop of light blocked, exposure duration doubles. (See first table)
- Use apps if you don’t mind bringing devices into the field
- Alternatively, use this approach outlined in this link: https://everlookphotography.wordpress.com/2016/05/24/quick-tips-live-view-simulation-and-long-exposures/
How long do I want?
- See the above section in ‘density recommendations’
- Start with that filter and adjust iso/aperture accordingly to achieve the exact shutter that you need for the scene.
- During your test exposures without the ND filters, take some dedicated shots with shorter shutter. You might like them more!
With or without filters?
- Think about combining filters to achieve a single exposure result
- Using an additional GND for the sky
- Avoid stacking ND filters as the filter in the 2nd slot will almost certainly let light leak in
- Think about taking an image for dark areas of the scene without the ND filter on as the ND filter will require a very long exposure for deeply shadowed areas. Blend them in post processing.
Ultimately, repetition leads to reflexes and if the routine is a reflex, more thought can go into the art of achieving a result instead of the mathematical and technical processes of using filters. Enjoy!
Disclosure: I am a Nisi brand ambassador who tries to write neutrally and objectively. If you are interested in purchasing filters after reading this article, feel free to email us dm@everlookphotography and I will be able to give a discount code for Australian customers.
Adelaide goes crazy in March. Adelaide is a sunset city. Its coast faces west and experiences some amazing conditions , particularly when the weather turns stiflingly warm and muggy. This happened for an extended period at the start of March madness this year and rather than being dbreezied* at home, I headed out a couple of times make use of the ongoing late sunsets offered by a prolonged daylight saving period.
*dbreezied : a term invented by USA photographer David Thompson : adj. The feeling of having the wind taken out of your sails when amazing light occurs and you, as a photographer, are nowhere near a landscape shooting possibility. Possible uses : “OMG did you see that nuclear sunset, here is a #dbreezied shot taken from my backyard”
Since returning from my last trip to Tasmania, I had been waiting for my metabones to return from BH. I might add that the returns process to BH was 100% painless and administration free. During this period, I had not been doing any shooting but the beckoning light lured me back toward the perfectly functional 6D sitting in a drawer waiting for use. Those who follow us may have realised that I have been doing a lot of complaining about the sony A7r2 in the field and loving it in the post process portion of image creation. The chance to go ‘back’ to a canon body was a real acid test in terms of whether it would feel like ‘going home’ or whether in actual fact, the sony did have its good points. I have mixed feelings.
In the field, the reliability of not having to play around with the metabones was a definite bonus. I did however notice a few things I preferred about the sony in the field. First was the ability to change iso directly through a dial (one button less than the default canon settings). Second , was the ability to have easy access to timed bracketed shooting. I know I could probably do this with the canon with some setting up but it’s nice that sony included that option in their default shooting modes. Lastly, I definitely prefer the Hejnar L bracket set up which places the camera and lens in a similar position that a lens collar and footing would. This is particularly relevant for me since I shoot with a remote which can get in the way when setting up an L plate attached to the camera body for vertical images. In reality, shooting with sony in the field wasn’t as bad as I had made it out to be , particularly since I now have an almost 100% foolproof ‘fix it’ routine for metabones errors. My main anxiety in the Tasmania trip was that I would have no backup should the sony fail in the wilderness.
Strangely enough, going back to canon raised another issue with post processing images. Sure the sony has the clear edge on resolution and dynamic range over my 6D but colour optimisation is not its strong point (particularly in the red spectrum). I’m not 100% sure why, but they seem much easier to ‘extract’ from canon RAW files than playing around with white balance and tints on the sony files. It just seems that much harder (albeit definitely possible) to portray a real golden colour or intense reds working with the sony files.
On the filter front, I’ve now acquired a Nisi 15 stop filter to experiment with. So far the conditions have been unkindly grey since I received this dark and cool piece of glass so I’ll probably have to wait until an upcoming weekend away to Kangaroo Island before I can reliably report back on its utility. As ever, watch this space!
In other random thoughts , I’ve been wondering why landscape photographers seem to act in a self destructive manner? I can’t imagine anything good coming of the quarrels that exist (mainly to do with post processing but some even to do with ‘turf wars’.) It’s OK for people to have different opinions. It’s OK for people to debate. It’s not OK to assume that your opinion is somehow more valid than the next person’s even if that opinion is the oft quoted ‘do what you like’ stance. Like it or not, whatever we as individuals do has an impact on the collective group , be it a tiny ripple or a tidal wave. Food for thought 🙂
Next update after a 4 day quickie to Kangaroo Island, then it’s time to hunt for some autumn colours locally!