Posted on 11 Comments

The Magic Cloth Technique – DIY Graduated Neutral Density Filter

I came across the magic cloth technique a few years ago when researching graduated neutral density filters but never actually got around to trying it. Recently a friend linked me to the stunning work that Tony Brackley-Prower had achieved by using this technique and was itching to try. The technique is a DIY neutral density filter that costs you nothing to try.

What are Neutral Density Filters?

Most photographers (myself included) use neutral density filters when shooting seascapes. These filters normally come in a rectangle size with black/dark at the top and clear at the bottom. Photographers use these filters when there is different levels of brightness in a scene. This is common when photographing seascapes on sunset where the sky can appear slightly brighter than the surrounding foreground. If photographed without filters this can result in the sky being over exposed as the camera attempts to compensate the darker foreground. We use neutral density filters to avoid this problem by placing the darker part of the filter at the top of the frame to capture a more even and natural exposure. Most neutral density filters are expensive with a Cokin set and a Lee kit . I was curious to how the magic cloth technique would compare to these more expensive neutral density filters.

Fast forward to December this year when I was visiting family and friends in my home town of Hobart, I gave the technique a try at Park Beach with some long exposures.

Magic Cloth Technique

The technique is appealing as it’s so simple and costs nothing. No surprises that the technique is based on using a cloth or even as Tony suggests, you can also use a sock, wallet, or cap. Really the possibilities are endless but the most important thing is finding an object which you can easily hold over the front over the camera to cover a certain part of the image. Once you’ve found a suitable object to use for the magic cloth technique, you’re now ready. The technique is best used for long exposures as this gives you greater control and flexibility over the image.

It is suggested to meter the image in your camera around 2 stops over exposed when using the technique to get the best possible exposure. Begin by starting the exposure and covering the lens with the object. Over time, gradually move the object up (towards the sky or the top of the frame). The slower you raise the cloth results in a darker grad. In simple terms this means your sky will receive less exposure and be considerably darker. If instead you raise the magic cloth faster, this will result in a less darker grad and brighter sky.

And really that’s all there is to the magic cloth technique. Experiment with the technique and you will slowly get a feel for how it works and how it might be beneficial for certain scenes. Now that I’ve tried the technique with seascapes I’d love to try with photographing waterfalls up close to avoid sea spray going all over my lens and to capture greater detail of the surrounding foliage areas.

You might also be interested in my waterfall photography guide. A thorough guide that covers waterfall photography, the ideal weather, equipment you’ll need, visual examples of how shutter speed works and other bits.

If you’re new to long exposures, my guide on daytime long exposures might also be of interest.

Hopefully this was helpful! 🙂

 

Posted on

Neutral Density Reference Chart

neutral density reference chart
neutral density exposure chart
One of my favourite long exposure photographs taken at Mortimer Bay, Tasmania

neutral density reference chart

A common question I receive from people is about how long they should set the shutter speed when using strong neutral density filters such as the 10 stop B+W 110 filter or NiSi Long Exposure Kit.  It’s a hard question to answer and I often point them to a chart (see end of post).

Rather than point you to a pdf file all the time I thought it would be more useful to point the information into a WordPress table to act as a quick reference for long exposure photography.

My Step by Step Process for Long Exposure Photography

I must be honest and tell you I’ve never used the chart and prefer to photograph a scene based on general feel for the scene. Over time you’ll learn how different conditions will need certain settings. For example the early stages of a sunrise (when it’s still dark) or the late stages of a sunset (when light is quickly fading) will require a significant exposure with the 10 stop attached. I’ll generally shoot around the 10 minute mark at F9 with a 100ISO. But if shooting during the sunset when there is more light available I’ll shoot more around F13 with a 2-5 minute exposure at 50ISO.  If on the other hand you’re shooting day time long exposure photographs around noon, I’ll crank the F stop to around 20-22, lower the ISO to 50 and shoot a test shot around the 1 minute mark and adjust accordingly. But to rehash these are my rules of thumb when shooting with the B+W 110 10 stop neutral density filter:

  • Early stage of a sunrise or late part of a sunset (when there is limited light available) – 10 minutes, F9~ with a 100-200 ISO (never any higher  due to a higher ISO increasing noise)
  • During sunset or sunrise when there is plenty of light available – 2-5 minutes, F13~ with a 50ISO
  • Day time light conditions (this can vary based on the scene being overcast or sunny) – 1~ minute, F20~ with a 50ISO

It’s not the most calculated way of doing things by any means but it’s a method that has worked well for me.  My best advice would be to play around in these scenes (early stages of a sunset, late stage of a sunset and day time) noting the settings for each scene and use these as a guide for when shooting scenes. It will mean less stuffing around when you arrive at a scene which is important when shooting a sunset and great light is disappearing quickly.

More Long Exposure Guides on this Blog

If you’re starting out in long exposure photography you might want to have a read over my free guide that looks at taking super long exposures (even during the daytime) that includes a guide on long exposures with before and after photographs and some equipment I recommend.  Also my waterfall photography guide also explores long exposures with the effect which long exposures can have when photographing waterfalls.

If you still have any questions after reading these articles please feel free to email me and I’ll be happy to help.

Free Neutral Density Exposure Chart

long exposure calculatorIf you want a copy of this neutral density exposure chart to carry in your camera bag,  attached is a PDF form that helps calculate long exposures with different neutral density filters. This will make a nice addition to any camera bag especially if you’re playing around with new filters.

Click (PDF 187kb)

Bare Meter Reading =1/80001/40001/20001/10001/5001/2501/1251/601/301/151/81/41/21s2s4s8s15s30s
ND2 (1)1/40001/20001/10001/5001/2501/1251/601/301/151/81/41/21s2s4s8s15s30s1m
CPL (1 2/3)*1/25001/12501/6401/3201/1601/801/401/201/101/52.51.31.6s3s6s13s25s50s1.66m
ND4 (2)1/20001/10001/5001/2501/1251/601/301/151/81/41/21s2s4s8s15s30s1m2m
ND8 (3)1/10001/5001/2501/1251/601/301/151/81/41/21s2s4s8s15s30s1m2m4m
2X ND4 or ND2 + ND3 (4)1/5001/2501/1251/601/301/151/81/41/21s2s4s8s15s30s1m2m4m8m
(5)1/2501/1251/601/301/151/81/41/21s2s4s8s15s30s1m2m4m8m16m
2X ND8 or ND64 (6)1/1251/601/301/151/81/41/21s2s4s8s15s30s1m2m4m8m16m32m
ND100 (6 2/3)1/801/401/201/101/52.51.31.6s3s6s13s25s50s1m 40s3m 20s6m 40s13m 20s26m 40s53m 20s
(7)1/601/301/151/81/41/21s2s4s8s15s30s1m2m4m8m16m32m64m
ND4 + ND64 (8)1/301/81/81/41/21s2s4s8s15s30s1m2m4m8m16m32m64m128m
ND400 (8 2/3)1/401/201/101/2.51/1.31.6s3s6s13s25s50s1m 40s3m 20s6m 40s13m 20s26m 40s53m 20s1 hr 47m3h 33m
(9)1/151/81/41/21s2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m
(10)1/81/41/21s2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m
(11)1/41/21s2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m
2X ND64 (12)1/21s2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m
ND10000 (13)1s2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m
(14)2s4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m
(15)4s8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m
(16)8s15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m22d 18h 8m
(17)15s30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m22d 18h 8m45d12h16m
(18)30s1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m22d 18h 8m45d12h16m91d 32m
(19)1m2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m22d 18h 8m45d12h16m91d 32m182d 1h 4m
ND1000000 (20)2m4m8m16m32m1h 4m2h 8m4h 16m8h 32m17h 4m1d 10h 8m2d 20h 16m5d 16h 32m11d 9h 4m22d 18h 8m45d12h16m91d 32m182d 1h 4m1 year