Welding glass help

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jimmy83

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Ive just got my hands a piece of shade 10 welding glass, and iam after your advice on the best way to attach it to my lens. I understand there are a number of different options, so iam not sure which would be best for me.
 
hi there.

I used expoxy glue to a 52mm cokin holder adapter.
just screws into place now, no fiddling with elastic bands.
 
Check out the tutorials section, I have made a tutorial with a guide of how to use the filter from start to finish. Hope it is of some use to you!
 
I've created a quick Excel spreadsheet that calculates the exposures (although worringly I end up with figures different from those in the tutorial, so that may be right, I haven't experimented with my timings yet, it's all hypothetical).

Link to screenshot (linky because it's a bit big for these pages) is:
http://www.fotothing.com/photos/8de/8debb89a23555c446a02267c9ef08fdf_ab7.jpg

If anyone would like a copy of the spreadsheet, please let me know and I'll happily email you a copy.

(Any comments appreciated as to why my timings are different from those J4mieP has in his tutorial would be appreciated. I suspect that I've done something blindingly obviously stupid, but I've no idea what!)
 
Could someone tell me on what filter ring adaptor I should buy?
 
If I were you, I'd put it on a 77mm Cokin Adapter. They're about 11 quid. Good old fashioned superglue should do the trick.

That way, you can use step-up rings to mount it on any lens you want.

If you glue it to something like a 52mm adapter, you're pretty much limited to only using it on lenses that have 52mm filter threads. If you use a step down filter on a 77mm lens to connect a 52mm filter, you're basically just going to have a circular view in the middle of your image and the outside of it all will be black.
 
That's the one, except that one's coming from China, so it could take a while to arrive at your door. :)
 
I just blu-tacked mine! Hehe! I am still not exactly sure what 'strength' my piece of glass is yet though. It gives even longer exposure time than in the tutorial.
 
Yeah thats cool I can wait. Dont you just use that adaptor and slot the welding glass into the adaptor and then attach that to the lens?
 
You can do that, the problem is you get light leaking in. Because the glass is so dark, it basically acts like a mirror, so you can see the lens itself reflecting in the glass. That's how I first tried it the other day when I realised it would fit.

Once I actually held the glass directly onto the end of the lens, all that went away and welcome back all my lovely contrast, goodbye light leaks and flares. :)
 
Ah right I see, so what do I actually stick the welding glass to? :thinking:
 
The adapter with the 77mm thread on it. Not the plastic bit that the filters normally slide into. :)
 
Ordered, many thanks
 
Ok ive got all my goodies...I was planning to cut the glass down to size so it slides into the adapter. Will this be ok?
 
Warning: the edges of the glass with be very sharp if you cut it. Best to try and file it down and duct tape the edges like I have.
 
Ok thanks for the warning. What did you mean about the duct tape?
 
As mine were a little sharp, I put tape around the edges. To attach the glass I actually stuck it to an old UV filter with Blutak then taped any excess around the filter from catching any light.
 
I recently bought 3 different pieces of welding glass (shades 8, 9 and 10) and already had a cokin p type adapter ring to fit my main lens... a long sausage of blue tack about 5mm thick is enough to stick it together (but dont leave any gaps).

I have only tested the shade 8, but i have found it correctly exposes the photograph at about 10 stops assuming the WB is correctly set (about 3100k with mine)
 
I got what amounted to an 11 stop welding glass off ebay for £1.50 and a correct thread filter holder converter for £2 off ebay and gluesd it onto that. Works a treat if a bit fiddly at times getting rid of the green cast.
 
I'm seriously considering trying this with my Nikon 14-24mm. Trouble is.... there is not a filter holder in existance for that lens (Lee have not yet released theirs) so I may be off to B&Q for a length of drainpipe to fit over the whole lens. Sick the welding glass over one end and slip the whole thing over the lens. Some of that draught excluder foam round the inside of the pipe should cut out light leaks. I figure it's the best way of doing this without damaging the lens. Expect to get a bit of vignetting as the original built in lens hood is a petal. Can someone please point me in the right direction for the nice guy on ebay selling the welding glass and I'll get glueing!
 
I wonder Alison, if you might be better making one up out of black foam board & gaffer tape rather than drain pipe (sort of like a matte box on a video camera, but with your welding glass on the end).

That way you can mount the welding glass horizontally to match your framing, and be able to shoot at a wider angle.

I don't know how wide that'd let you go, but I imagine it wouldn't be as limiting as using drain pipe.
 
This link was where I bought mine from:
http://cgi.ebay.co.uk/Glass-filter-...tem&pt=LH_DefaultDomain_3&hash=item2a085987a6
a long time back.
If it does not work do a search for darkmutton welding glass. I did not bother cutting mine down so it is his standard size but I have a pack it goes in. I see he does 9,10 and 11 sizes now and has gone up to £2.50.
When I bought he was wonderig what was going on with a sudden influx of orders as he did not realise people were using them in photography. As I said you need to use colour adjustments in software to correct green tones - look really cool in black and white. Must get mine out again as I have not used it for ages
 
jinky said:
As I said you need to use colour adjustments in software to correct green tones - look really cool in black and white. Must get mine out again as I have not used it for ages
Click to expand...

An example of Cardiff Bay yesterday.

F10
30sec
35mm



How did you work out how many stops the glass reduces the amount of light by? I just used the info someone posted on here which is generally ok but can overexpose slightly.
 
Trial and error.

Best bet...

Stick your camera on a tripod, point it at a plain evenly lit section of wall in your house. Let the camera meter it and take a shot.

Put your welding glass on the end, add 10 stops to your shutter speed and take a shot (shoot raw). Compare the histograms, then adjust your shutter speed up or down til you get histograms that look right.

Then, once you've got a shutter speed that gives you appropriate results, work out how many stops that is, then you know how many to add "on the job", so to speak.

If you have an iPhone or an iPod Touch, grab an app called LongTime (it's free). You just enter your normally metered shutter speed for a scene, tell it how many stops you wanna add, and it tells you what you need to set your shutter speed at.
 
Ok ive got all my goodies...I was planning to cut the glass down to size so it slides into the adapter
Click to expand...

warning! do NOT try and cut the glass! a few people on here have tried it and failed miserably, with it cracking through the middle.

You are not trying to slide it in the filter holder anyway - the best way to do it is to stick it DIRECTLY onto the 77mm adapter ring. forget trying to slide it into the filter holder, there are too many light leaks.

but don't make the same mistake as i did! i just stuck the adapter ring on with Araldite (which worked a treat) but when i screwed it onto the front of my lens and tightened it up it isn't level! screw the adapter ring on first, mark off the top of the adapter ring and line the top of the welding glass up with that BEFORE you glue it on! It's no big deal, it just looks wonky.
 
As I said you need to use colour adjustments in software to correct green tones
Click to expand...

WRONG..

You need to set the custom white balance on your camera! There's a good tutorial in the Flickr "welding glass" group. Once it is set all you need to do is select the pre-set custom white balance in camera and all your shots will be corrected. in cam.
 
Custom white balance alone doesn't always work. It doesn't just shift the white balance, it actually blocks certain colours from getting through.

There aren't the strict optical quality controls for photographic purposes on welding glass that there are on something like the B+W 10 stop or the Lee big stopper, and there are MANY MANY manufacturers of it with varying standards.

The PP for one piece of glass might be VERY different from the PP for a different piece of glass made by a different manufacturer in probably another continent.
 
The PP for one piece of glass might be VERY different from the PP for a different piece of glass made by a different manufacturer in probably another continent
Click to expand...

I think you getting the wrong end of the stick. You put YOUR piece of welding glass on the front of the lens, take the picture, go to camera menu and select custom WB, select the image you just took and hey presto - every image you take under that setting is then corrected.
 
bomberman said:
I think you getting the wrong end of the stick. You put YOUR piece of welding glass on the front of the lens, take the picture, go to camera menu and select custom WB, select the image you just took and hey presto - every image you take under that setting is then corrected.
Click to expand...

I did that but still get a green'ish cast to the shots which I have to PP.
 
No, I think YOU'RE getting the wrong end of the stick.

That method doesn't work for every different manufacturer of welding glass out there. :)
 
OK well, it works for me and it's a lot easier than trying to PP them from scratch.

Tim
 
You mean it works for your welding glass. :)

I don't have to PP from scratch, I simply load the image up into ACR, and click a preset I made the first day I got the welding glass, job done.

Just that white balance alone doesn't always work.
 
realmofconfusion said:
I've created a quick Excel spreadsheet that calculates the exposures (although worringly I end up with figures different from those in the tutorial, so that may be right, I haven't experimented with my timings yet, it's all hypothetical).

Link to screenshot (linky because it's a bit big for these pages) is:
http://www.fotothing.com/photos/8de/8debb89a23555c446a02267c9ef08fdf_ab7.jpg

If anyone would like a copy of the spreadsheet, please let me know and I'll happily email you a copy.

(Any comments appreciated as to why my timings are different from those J4mieP has in his tutorial would be appreciated. I suspect that I've done something blindingly obviously stupid, but I've no idea what!)
Click to expand...

Thank you so very much for this, last time I was knee deep in the clyde, kit all over the place, not enough fingers ...
 
Kaouthia said:
I wonder Alison, if you might be better making one up out of black foam board & gaffer tape rather than drain pipe (sort of like a matte box on a video camera, but with your welding glass on the end).

That way you can mount the welding glass horizontally to match your framing, and be able to shoot at a wider angle.

I don't know how wide that'd let you go, but I imagine it wouldn't be as limiting as using drain pipe.
Click to expand...

Hmmm get the idea John but the pipe would be capable of rotating so getting it horizontal should not be a problem and I plan on sticking the welding glass to the pipe so it fits flush to the lens hood so that, in theory, should be as wide as you can possibly get? The length of the pipe and the foam inside it should be long enough if I cut it to length so it comes right back to the camera body so it should have some stability.
 
AliB said:
Hmmm get the idea John but the pipe would be capable of rotating so getting it horizontal should not be a problem
Click to expand...

Yes, but a pipe is cylindrical. No matter how you spin it, it's still going to be a circle at the end. :)

Edit : Ooooh, never mind, I get what you're doing now. See, I was thinking replace the lens hood completely, because otherwise I think the longer bits at the top and bottom are going force you to have it stuck out too far, and cut into the sides a bit.
 
The 14-24 has a built in lens hood because it is essentially...a dome! So Nikon figured (quite rightly) that we are not safe to be let out without something to protect it and filters don't fit so they gave us a nice built in petal :) If I can get the glass snug up against the lens hood it will be as close as I can physically get it but I still think I'll get a bit of vignetting at 14mm. I'll give it a go :)
 
ahhh I gotcha. I haven't actually played with the 14-24. Looked at a bunch of sample images shot with it when I was looking at a UWA but went with the Sigma.
 
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