How to shoot long exposures for only $1

Jun 24, 2016

John Aldred

John Aldred is a photographer with over 20 years of experience in the portrait and commercial worlds. He is based in Scotland and has been an early adopter – and occasional beta tester – of almost every digital imaging technology in that time. As well as his creative visual work, John uses 3D printing, electronics and programming to create his own photography and filmmaking tools and consults for a number of brands across the industry.

How to shoot long exposures for only $1

Jun 24, 2016

John Aldred

John Aldred is a photographer with over 20 years of experience in the portrait and commercial worlds. He is based in Scotland and has been an early adopter – and occasional beta tester – of almost every digital imaging technology in that time. As well as his creative visual work, John uses 3D printing, electronics and programming to create his own photography and filmmaking tools and consults for a number of brands across the industry.

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I find long exposures to be great fun, especially once you start really stopping down the light and extending that shutter to ridiculous lengths.  The costs of getting started, however, can add up very quickly.

In Mathieu Stern’s latest video, which features long exposure photographer Thibault Roland, we are shown how we can get started very inexpensively using welding glass as a filter over our lens to cut down the amount of light hitting our sensor, and lengthening those shutter speeds.

YouTube video

I started off with a couple of inexpensive Cokin resin filters when I first wanted to have a go at long exposures.  I didn’t know much about them at the time, and they were on the shelf at my local camera shop.  So, I got a 2 stop ND grad, and a 3 stop ND.  On a dull day, they worked out pretty good for letting me get exposures of 2-3 seconds.

Then I read of this tip with the welding glass on a photography forum about ten years ago and decided to give it a go.  Again, I didn’t really know much about what I was doing with them then, but I was rather pleased with my results.

I’ve since upgraded my neutral density kit into Schneider 4×5.65″ and B+W 77mm threaded filters, but the welding glass really isn’t a bad way started getting into it.  In fact, I just ordered a couple of pieces of it from eBay so that I can test a few theories on how to correct the colour shifts effectively (and if any of those theories pan out, I’ll definitely be posting a tutorial for you guys).

At the very least, the welding glass is going to give you a good idea on whether or not you even like the process of creating long exposures, and will give you some practical insight before you spend a couple of hundred $ on something a little higher end.

One thing to note with welding glass is that they don’t come in “stops” like neutral density.  Instead they come with measurements called “Shades”, but the number can be converted.

According to The Astronomy Nexus, the formula breaks down a little something like this.

OD = -log T
SN = 1 + (7/3) OD

Where T is the amount of visible light that passes through the glass and SN is the “shade number” of the welding glass.  If you want to read more about the maths, go ahead and read the page at The Astronomy Nexus or the comments on this post at Stack Exchange.  For the rest of you, here’s a quick list of approximate equivalences.

  • Shade 1.7 = 1 stop
  • Shade 2.5  = 2 stops
  • Shade 3 = 3 stops
  • Shade 4 = 4 stops
  • Shade 5 = 5 stops
  • Shade 6 = 6 2/3 stops
  • Shade 7 = 9 stops
  • Shade 8 = 10 stops
  • Shade 9 = 12 stops
  • Shade 10 = 13 stops
  • Shade 11 = 15 stops
  • Shade 13 = 16 stops
  • Shade 14 = 18 stops

Remember, these numbers only apply to visible light.  Infrared and ultraviolet are treated a little differently, by both ND filters (especially the IR corrected ones) and welding glass, so some experimentation will be required.

Do you use welding glass for your long exposures?  Have you tried it and loved it?  Or hated it?  Let us know your thoughts and experiences in the comments, and show off some of your long exposure images.

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John Aldred

John Aldred

John Aldred is a photographer with over 20 years of experience in the portrait and commercial worlds. He is based in Scotland and has been an early adopter – and occasional beta tester – of almost every digital imaging technology in that time. As well as his creative visual work, John uses 3D printing, electronics and programming to create his own photography and filmmaking tools and consults for a number of brands across the industry.

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18 responses to “How to shoot long exposures for only $1”

  1. Stephen Lenman Avatar
    Stephen Lenman

    very cool

  2. aleroe Avatar
    aleroe

    How’s the optical quality of welding glass?

    1. Sean Avatar
      Sean

      Did you not read the article or listen to the video? :) That was discussed.

      1. aleroe Avatar
        aleroe

        I read the article but I didn’t watch the video (it’s 13 minutes long). The article didn’t mention it. But if it’s in the video, I withdraw my question. The fact that I don’t care enough to spend 13 minutes to find the answer is, after all, my problem, not yours. ;-)

        1. Kaouthia Avatar
          Kaouthia

          The short version is that it varies, but it’ll never be as good as optical glass designed for this purpose. :)

          So, you get what you pay for, really.

  3. Wing Wong Avatar
    Wing Wong

    Welding glass isn’t exactly perfectly flat. Some glass has defects in it, so it’s a chance thing. My glass has a divet in one of the corners. Not really an issue, just reposition it out of your lens’ frame.

    Almost all welding glass will impart a color shift to the captured image, which you can mostly get rid of if you make a white balance profile against the glass for a specific exposure length of time. Part of the reason bw conversions look better.

    1. Kaouthia Avatar
      Kaouthia

      Yeah, but it’s a fun way for people to get started and give it a go without a huge outlay. :)

  4. Richard Joseph Avatar
    Richard Joseph

    Anish Kumar Palakunnel Sivadas

  5. Richie Schwartz Avatar
    Richie Schwartz

    I would charge more than $1 to shoot long exposures

    1. John Aldred Avatar
      John Aldred

      Would you charge by the second or by the minute? ;)

    2. Richie Schwartz Avatar
      Richie Schwartz

      To cover all bases I would charge for the second minute

  6. Vertex Avatar
    Vertex

    money for a expensive body.. but too cheap to buy correct filters…. a typical sony users.

    1. timothyf7 Avatar
      timothyf7

      Why spend the money, if you are not sure you want to invest more money. Like stated in the article and video, it is a good way to try out something without sinking up to $700 (as mentioned in the video) and find out it is not something you are really interested in doing long term. When I was wondering about micro photography, I started with some inexpensive tubes. When I realized that I really enjoyed it, I invested in more expensive equipment. Had I not cared for it much, I was only out $20. It isn’t all about blowing hundreds just so you can say “I have expensive equipment”, it is about a smart way to see if it is worth purchasing better equipment.

      1. Kaouthia Avatar
        Kaouthia

        Yup, absolutely. Between my Schneider & B+W ND filters, that’s well over a grand’s worth. That’s potentially more than the cost of the camera itself and the lens for some photographers who would like to try out long exposures.

        This is a good inexpensive way to give it a go without having to eat too much of a loss if you don’t like it.

  7. Garr8 Avatar
    Garr8

    I picked up on using welding glass several years ago and developed a preset for Adobe Lightroom to counteract the hue. Download link… https://www.ephotozine.com/download/use-welding-glass-as-10-stops-nd-filter-317/download-file/1339918445_john-garrett-10-stopper.lrtemplate

  8. Don Butler Avatar
    Don Butler

    I have yet to find a welding lens for a dollar.

    1. timothyf7 Avatar
      timothyf7

      He actually spent more for the pack, but divided the cost per piece. Amazon has has the glass for $5-6.

    2. Kaouthia Avatar
      Kaouthia

      I managed to pick up several pieces on eBay UK for £1 each, and I’ve seen quite a few for $1 on Amazon US, too.