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Homebrew Welder's Glass Filter

====== UPDATE as my 'Club' membership has expired in the uncertainty of the IMA takeover many of the images in the article are not in my most recent 200 and thus will not be visible in the article ======





I've posted a couple of images on ipernity using ND filters made from welder's glass, a cheap way of emulating a Lee Big Stopper filter, and you can go to much higher ND factors too, I've made 900x and a 9600x ND and another which I guess is around 100,000x but I've not found a use for yet.

I originally made the filters when I was using a 'point and shoot' and really didn't want to spend as much on an ND as I had on the camera. If you buy the bits off eBay the total cost of a filter is around £3

London Eye through #8 Welder's Glass.

Log Fire through #8 welder's glass

Motorway, normal and through welder's glass, using a 'point and shoot' compact

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Here's how to make a welder's glass filter for a camera with screw in filters

what you need:
a piece of welder's glass: #8 welder's glass is around 900x and #10 welder's glass around 9600x exposure, so #8 glass is similar to a Lee Big Stopper (1000x). The welder's glass can be bought from eBay, normally around £2, various grades, darknesses, are available and various sizes.

a mount for the glass

I used a step up ring (approx £1 from eBay) for the screw in filter and a small cut off piece of waste pipe,spray painted matt black, for the point and shoot (£0 from the scrap pile).

check the ring alignment


screw the step up ring on to the camera, and note where the top of the ring is, you need to do this so when the glass is fixed it lines up square when screwed on to the camera. Here the inscribed 77mm is at the top.

cut the glass to size

I used a 77mm-82mm stepup ring which is just the right size for the 3.25inch wide size the glass comes in, is too long. Mark the glass at 85mm, and score with a glass cutter.





snap the glass to size by resting it on a couple of matchsticks on a firm surface and press down along the score using something like a block of hardwood the glass, and you should get a clean break . . .

smooth the sharp glass edges


I used 280 grade wet or dry paper


glue the ring to the glass


I used contact adhesive to do this as it gives a good light seal, which is very important, as the slightest leak will cause problems.


Coat the ring all the way around, and lower the glass on, press lightly and leave the glue to dry.

here's the finished thing.


Note the 77mm marking is aligned with the edge of the glass, so that when it's mounted on to the lens the glass will be square on the camera.

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Colour Correction

Welder's glass has a very strong green cast, too green to be corrected by most auto white balances, and quite difficult to remove satisfactorily in post. There are three work arounds for this:

1) Shoot in / convert to mono, lots of people work this way, and the mono suits a lot of long exposure images.

2) If you have a camera with custom white balance take a shot through the filter and use this as the WB reference. Great results.

3) If you don't have custom white balance you can use a piece of magenta gel over the welder's glass to bring the colour cast within range of the AWB, the image below was taken with a point and shoot with #8 welder's glass and a magenta gel:



Milky Water taken with a point and shoot




Point and shoot filter with the colour correction gel

This filter is simply a snug fit over the P+S lens barrel.

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here's an Ipernity group with more images: www.ipernity.com/group/weldingglass

thanks to Alby Oakshott www.ipernity.com/home/albyoakshott for the original inspiration in 'the other place'

11 comments

Amazingstoker said:

Any questions or feed back, please let me know . . .

and here's some others of mine: www.ipernity.com/doc/amazingstoker/album/448647
5 years ago

LutzP said:

Thanks for sharing, Stoker. Very interesting indeed.
5 years ago ( translate )

Amazingstoker replied to LutzP:

thanks LutzP
5 years ago ( translate )

Dutt Changgle said:

I am all over this! Great way to kick out the long exposures.
Thanks for the idea.
5 years ago

Amazingstoker replied to Dutt Changgle:

Look forward to seeing some results, the thanks are all to Alby Oakshott really
5 years ago

The Limbo Connection said:

I'm not going to do this, but I rejoice in the knowing how and applaud the clear and concise directions. In a time characterised by imprecise and long-winded English, how good it is to find purity.
5 years ago

Amazingstoker replied to The Limbo Connection:

Thanks for your very kind comments on the article; puffed up, padded out hand wavy writing annoys me too . . . .
5 years ago

Erhard Bernstein said:

Great idea and implementation ...
5 years ago ( translate )

Amazingstoker replied to Erhard Bernstein:

thanks Erhard
5 years ago

Roger (Grisly) said:

I'm off to the shed for a bit of DIY, great info many thanks.
5 years ago

Amazingstoker replied to Roger (Grisly):

:) gotta do something with the shed, now it's no longer a darkroom. . . .
5 years ago