ND filter options..

sunny2004

Hi folks,
I am interested in getting a ND filter with at least 10 stops... min and more if possible..

I really want a square filter if possible as I use a range of lenses..

Whats the options ??

oshead

Some of the lads on here use a welders mask to great effect. Cost only a couple of Euro. They have a green hue so If you shoot in RAW you'll be able to correct later in Lightroom or Aperture. You can search for posts by kjt, cambo_gueno and I think longshanks. The latter being the one to come here with the idea.

I use the Cokin P system. Apparently the filters are not the best. But you can buy Lee or Hi-tec glass, they'll fit and do a nice job too. The problem is you'll need to buy a ring adapter for all your different size lenses. A way around this is to buy the Universal Ring Adapter. It's a bit figity but works a treat.

stabo

Could be wrong but i think 10 stop is the highest you can get. Just got a ND and ND grad recently,pick them up in Gunn's for 21 euro each.

sunny2004

OSHEAD,, welding glass sounds like fun cheers man for the info

stabo, what strength where the filters you bought ?

stabo

The ND was 6 stop and the ND grad was 2 stop.

sunny2004

stabo wrote: »

The ND was 6 stop and the ND grad was 2 stop.

where they square ?

oshead

sunny2004 wrote: »

OSHEAD,, welding glass sounds like fun cheers man for the info

stabo, what strength where the filters you bought ?

Yeah, I gotta try it some time.

stabo

sunny2004 wrote: »

where they square ?

Yep.

PaulieC

you'll pay over 100 euros for a 'proper' 10-stop filter. welding glass costs about 3 quid, well worth getting one to play around and see if you like the effect a filter like this gives.

honerbright

Where would be the best place to pick up welding glass? I've the week off work and fancy experimenting

stabo

honerbright wrote: »

Where would be the best place to pick up welding glass? I've the week off work and fancy experimenting

Most hardware shops or engineering outlets.

ThOnda

I have two ND8 filters and I've used already both + ISO down to 50. It works a treat, but requires some patience. 5+ min. exposures are magical. If you are patient enough
The circular ND8 filters are quite cheap from 7dayshop, but you could find them on e-bay in stores that offer even free shipment.

smelltheglove

I only have the nd4, I use for weddings on very bright days when strong sun can cause issues. The filter itself cost around €60 last year.

I've seen some results with welding glass and the images look amazing. Just do a search on flickr with welding glass and youll see a great variety of results.

jpb1974

Square Slot In - Lee 'Big Stopper'
http://www.leefilters.com/camera/news/articles/ref:N4B8F96517C324/


Screw On - B+W 110 10 Stop Filter
http://www.warehouseexpress.com/buy-b-w-67mm-nd-110-3-0-sh-filter/p1013507

I can vouch for the welder's mask glass too... a friend tried it... probably best if you convert your result to B+W as the colour casts can be horrible.

PaulieC

this is taken with a welder glass (120 seconds at F8, ISO 100)


as mentioned, when using these black & white is best given the colour cast it gives. Even when corrected, the colour is still very 70's polaroid...e.g.

oshead

cambo_gueno wrote: »

Even when corrected, the colour is still very 70's polaroid...e.g.

The colour correction on this looks excellent. The greens have taken on a new strength in dept or something. Maybe a slight blue cast.

Have you tried to use a grey card to help correct in lightroom afterwards? I might pick one up today and do a few test shots.

sunny2004

how are you connecting the welders glass to the front of the lens ?
and how are you getting the exposure ?

PaulieC

sunny2004 wrote: »

how are you connecting the welders glass to the front of the lens ?

two big elastic bands each side of the lens

sunny2004 wrote: »

and how are you getting the exposure ?

guesswork really. On a bright day like today, I would go for F8|ISO100|120 seconds.

PaulieC

oshead wrote: »

The colour correction on this looks excellent. The greens have taken on a new strength in dept or something. Maybe a slight blue cast.

Have you tried to use a grey card to help correct in lightroom afterwards? I might pick one up today and do a few test shots.

how does one go about this ?

Ballyman

The easiest way to sort out the colour cast is to take a short exposure shot of the scene first. It should have a very bad green tint on it. Save this as your WB (if your camera allows)
When you take a long expoisure shot then use the saved WB as your WB in camera and it should do a pretty good job of sorting it out for you. You can do the final tweaks afterwards in Lightroom.

As regards the exposure times. I have a Darkness rating of 10 on my welders glass. From messing around with it, it's actually a 13 stop filter so the exposure times can be a bit mental, especially in lower light. If you are going to buy one then I'd recommend getting something less than 10 if you can so the exposures aren't as long.

I've attached a sheet for calculating exposure times that I can't remember where I got but the guy who wrote it has put his name on it.

1. Set up the shot as normal but with a fast shutter speed. Use this shot as our custom WB.
2. Now set the aperture and shutter that you would use to expose the scene correctly. Note the shutter speed and using the sheet, calculate a 10 or 13 stop difference. Dial in the new shutter speed and focus the camera.
3. Turn the AF off on the lens and attach the filter. Take the shot and apply your custom WB.
4. Bob is now your uncle.

You can also download an iPhone App if you scour the net!

sheesh

*runs to hardware store

oshead

sunny2004 wrote: »

how are you connecting the welders glass to the front of the lens ?
and how are you getting the exposure ?

I was down in Weldtech today and picked up some filters for €1 a pop. They fit the Cokin filter holders perfectly. Exactly the right size. You'd think they were made for it. I got three different density levels. They are marked 8, 10, 13. I'll have to test to see if they use the same f stop system for measuring the amount of light.

As far as getting the exposure, you could use the handy chart posted by Ballyman after you figure out, by trial and error of course, the density of filter you have on the lense.

cambo_gueno wrote: »

how does one go about this ?

Ballymans solution should work fine. The camera maker usually recommend that you shoot a white sheet of paper a couple of feet in front of the camera and use that.

I was thinking more like a Whibal card or something similar. I use this when I remember, especially if the lighting situation is a little bit funny.

Another is the Expodisc. You use this to set the white balance in camera and just shoot away.

I have both and it's a toss of a coin as to which will work better.

melekalikimaka

wheres this weldtech?

oshead

sunny2004 wrote: »

how are you connecting the welders glass to the front of the lens ?

Took a few shots of the Cokin Universal filter holder with my 24-70mm.

melekalikimaka wrote: »

wheres this weldtech?

It's in Just pass Glasnevin Cemetery in the industrial estate beside Woodies. But you should be able to get them somewhere on the southside easily enough in a large hardware type store or builders providers. If they don't have them they should be able to tell you where to get them in your area.
Try this. First link on Google.

.

Ballyman

oshead wrote: »

Another is the Expodisc. You use this to set the white balance in camera and just shoot away.

Does this thing actually work? It would be ideal for studio shooting I would imagine?

Where did you get it and how much was it?

And, would you recommend it?

melekalikimaka

Ballyman wrote: »

Does this thing actually work? It would be ideal for studio shooting I would imagine?

Where did you get it and how much was it?

And, would you recommend it?

just shoot in raw, edit in lightroom, and copy the edit wb setting on the first one to all images in set... simples

Ballyman

It's never as easy as that though.

When you fix the WB initially, to your eye it looks fine so you copy it to all the images. However when you look at it again a day later you sometimes notice a slight green or magenta tinge that you didn't spot originally as any change in WB can look better than the original and even make you think it's correct when in actual fact it isn't. This is the same with most processing for me. Every image when processed can look totally different a few hours later when you've been away from the PC for a while and your eyes adjust back to normality!

Anything that can help me get it right from the word go is good in my book!

melekalikimaka

http://www.dpreview.com/news/1004/10040802colorchecker.asp

saw this the other day.

oshead

Ballyman wrote: »

Does this thing actually work? It would be ideal for studio shooting I would imagine?

Where did you get it and how much was it?

And, would you recommend it?

Bought it off one of the stalls (probably Bakers) at Photofest Ireland two or three years ago. About €50 if I remember correctly. It does work, that's for sure. I don't always use it in camera. Though thats the preferred way. I usually just pop it on the lense and point it in the direction of the most light and take the shot. Then in Lightroom, I balance that as if I where selecting a grey area from a pic. As I'm going along, if the light changes significantly, I pop it on again and incorporate that into my workflow. So in Lightroom, it's simply a case of using each new Expo image as the current white balance sample. Couldn't be any easier. I've used it both in studio, outdoors and under mixed lighting. For mixed lighting, I would sample the light from a scene that was affecting the skin tones the most and use that as the sample.

Would I recommend it? Many a time I've gone out shooting and forgot to bring it with me. Didn't stop me shooting and didn't really affect the way I shoot. If you are looking to buy one, you can have a lend of mine for a while to see if it's something you'd add to your general practices.

oshead

Ballyman wrote: »

It's never as easy as that though.

When you fix the WB initially, to your eye it looks fine so you copy it to all the images. However when you look at it again a day later you sometimes notice a slight green or magenta tinge that you didn't spot originally as any change in WB can look better than the original and even make you think it's correct when in actual fact it isn't. This is the same with most processing for me. Every image when processed can look totally different a few hours later when you've been away from the PC for a while and your eyes adjust back to normality!

Anything that can help me get it right from the word go is good in my book!

I agree, There's no substitute for having a known value. In this case the light temp and being able to replicate it from one shot to the next. Any system that uses your eyes to judge colour is flawed.

charybdis

oshead wrote: »

I agree, There's no substitute for having a known value. In this case the light temp and being able to replicate it from one shot to the next. Any system that uses your eyes to judge colour is flawed.

You can put something that you know is white or at least middle grey in a setup shot to calibrate your color temperature. You can apply this correction to the setup shot's RAW file and then copy the white balance settings across to other photographs taken in the same light with the same filter.

PaulieC

melekalikimaka wrote: »

http://www.dpreview.com/news/1004/10040802colorchecker.asp

saw this the other day.

not sure how eyeshadow would help here

sunny2004

got another question, how sharp are the images ? as in how good is the glass in the welders filters ?

oshead

sunny2004 wrote: »

got another question, how sharp are the images ? as in how good is the glass in the welders filters ?

My first tests 60mm, f2.8 @ ISO 3200 for 120 sec and not as sharp as i'd like. I'll try some more settings after I get the little one off to bed.

PaulieC

ISO 3200 and f2.8? musta been verylow light?

Kbeg3

I've been experimenting with welding glass as well, using a Cokin P holder to attach it to the lens, but there is space between the filter and lens which lets light in and I get weird reflections. Must get some tape and fill in the gaps. Failing that I'll get some elastic bands:)

oshead

cambo_gueno wrote: »

ISO 3200 and f2.8? musta been verylow light?

Yeah, in the sitting room using only a shaded window for light. I might pop it with the studio strobes this evening to cut down the exposure time.

Kbeg3 wrote: »

I've been experimenting with welding glass as well, using a Cokin P holder to attach it to the lens, but there is space between the filter and lens which lets light in and I get weird reflections. Must get some tape and fill in the gaps. Failing that I'll get some elastic bands:)

The Universal bracket and P holder allow me to have the glass tight up against the lense.

Cover the eye piece too. I've heard you can get some weird looking light in from there on long exposures. Though, it's probably one of those urban myths.

melekalikimaka

oshead wrote: »

My first tests 60mm, f2.8 @ ISO 3200 for 120 sec and not as sharp as i'd like.

yeah with the filter over youd wanna close down the aperture, should sharpen up things a bit

oshead

melekalikimaka wrote: »

yeah with the filter over youd wanna close down the aperture, should sharpen up things a bit

Yeah, will do.

stabo

sunny2004 wrote: »

how are you connecting the welders glass to the front of the lens ?
and how are you getting the exposure ?

You could get an adapter ring and glue the glass onto it,this would stop light leakage.

PaulieC

oshead wrote: »

My first tests 60mm, f2.8 @ ISO 3200 for 120 sec and not as sharp as i'd like. I'll try some more settings after I get the little one off to bed.

Here's a full-size pic that I took on Saturday evening at F8 with a Canon 17-40 Lens. There is no sharpening applied. I find it to be acceptably sharp.

stabo

cambo_gueno wrote: »

Here's a full-size pic that I took on Saturday evening at F8 with a Canon 17-40 Lens. There is no sharpening applied. I find it to be acceptably sharp.

Cant view it unless your on Flickr. Would like to see it.

sunny2004

Cheers guys, great info and its bloody interesting !!

oshead

Can't view it either.

PaulieC

Sorry, here it is on Pix.ie

http://photos5.pix.ie/1A/08/1A08CDAF142A47F5872B887962CBD495.jpg

stabo

^ wow super shot.

oshead

That's bloody good. Super sharpness considering everything. Where did you get your filter?

I just tried shooting a gray card with the filter that I got today. Some more tests. This time, 60mm, f9 on bulb and I popped the studio flash (500 w/s) at it 16 times. It still came underexposed by 3 - 4 stops. It's just way too dark/dense. I'll have to get another one.

Another thing I was trying earlier. Balancing it out in Lightroom it seemed there wasn't enough magenta on the second color balance slider to knock out the greeness of the filter. So I decided to try and counter it using the in camera menu option, WB SHIFT/BK and set it to B3, M9/+0 (Blue 3, Magenta 9). This should go a fair way to help cancel out all the green hue of the filter.