WTB: Lee Big Stopper

[Tony B]

Do you have a Big Stopper that you would like to sell because it gets little use? Please PM me.

Thank you

[Paul Mitchell]

I could probably count on one hand the amount of times I've used mine... sadly my son has pilfered it for his A level photography project and it would be more than my life's worth to extract it from him (added to the fact he's over 6ft!). If it's the ridiculous waiting time putting you off buying one new you could try these http://www.7dayshop.com/catalog/product ... _id=111260 (there's many other filter sizes)

Paul

[Joanna Carter]

Due to the long back order times from Lee, I have checked with Formatt Filters and they have a resin 10 stop filter for around £60 + VAT. They are also quite busy but only have a 2-3 week waiting time. Unfortunately, I can't do any discount, like I could have done on Lee.

[AlexeyD]

Due to the long back order times from Lee, I have checked with Formatt Filters and they have a resin 10 stop filter for around £60 + VAT. They are also quite busy but only have a 2-3 week waiting time. Unfortunately, I can't do any discount, like I could have done on Lee.

The Formatt one is not quite the same. Apart from having a more noticable cast, unlike Lee it does not have a light sealing rim that helps a lot to avoid light leaks during long exposures. At least that was my previous experience - if that has changed and they do it now then I'd be very interested to know.

[Joanna Carter]

Apparently, in speaking to them yesterday, they have produced a newer, better version. But, as they won't let me have a sample without paying, I cannot say whether it loses the problem of colour casts that seemed to affect their ND filters. As to the light seal, I tend to use a compendium hood anyway and then drape my focusing cloth over the filter slots.

[AlexeyD]

I could probably count on one hand the amount of times I've used mine... sadly my son has pilfered it for his A level photography project and it would be more than my life's worth to extract it from him (added to the fact he's over 6ft!). If it's the ridiculous waiting time putting you off buying one new you could try these http://www.7dayshop.com/catalog/product ... _id=111260 (there's many other filter sizes)

From the previous experience using those kind of variable ND I would really advise against them. They are constructed from 2 polarisers twisted against each other so that they block the light. The idea is good but it does not work very well with a wide angle lenses and higher ND levels. And not even very wide angles - on 35mm formats the uneven effects could be seen on 24mm. Those seem to be a bit more dependent on a lens rather than focal length and affecting the wide angle lens with larger front element where it sits closer to the filter. Basically you get dark cross pattern from corner to corner at higher levels of ND - it gets more pronounced as the focal length gets wider as well.

[AlexeyD]

Apparently, in speaking to them yesterday, they have produced a newer, better version. But, as they won't let me have a sample without paying, I cannot say whether it loses the problem of colour casts that seemed to affect their ND filters. As to the light seal, I tend to use a compendium hood anyway and then drape my focusing cloth over the filter slots.

Cast is not as critical for me as the light sealing solution. I use compendium as well but I'd prefer not to fuss with the cloth every time. Considering that exposures can be very long, a permanent and reliable sealing solution would be better imo. Lee approach is quite simple in this respect - I don't understand why Formatt can't easily do the same...

[Joanna Carter]

The majority of my colour correction filters are Formatt and they are a lot thinner than the Lee ones; which may make it more difficult to fit such a seal. OTOH, I guess you get what you pay for I just wish I could afford to replace my NDs with Lee

[TimH]

Hi Tony et al - I went for a 6 stops - I reckoned if I wanted more, I could add the dark bit of an ND to the light path (as I carry 1,2 and 3 stop anyways). Moreover as 77mm is my current biggest filter size, I bought one that size.. SRB GRITURN supplied step up/down rings give me a good fit to all my lenses for waaaay much less cost than separate filters !!!. Note I bought one of the earlier ones thats uncoated - cant say it seems to be an issue tho I did use dark cloth as a drape over hood. (same as when shooting I/R). I cant find receipt for it so I cant remember where I got it but twas flebay shoppe somewhere.
Could even be these people as they have such a shop too as well as this normal one.

http://www.fotosense.co.uk/b-w-106-1-8- ... ilter.html

Regards Tim.........

[AlexeyD]

The majority of my colour correction filters are Formatt and they are a lot thinner than the Lee ones; which may make it more difficult to fit such a seal. OTOH, I guess you get what you pay for I just wish I could afford to replace my NDs with Lee

The seal is a foamy substance that compresses (as least from what I have been told by the chap owning it) so my guess is that it would not be awfully expensive nor difficult to make it slightly thicker. I do wish I could afford all NDs to be Lee as well - so far only managed to afford a set of Lee grads

[Tony B]

Hi TimH

Thanks for your comments.

The link you gave advertised the B&W filter. The new magazine, Advanced Photographer did a survey of 10-stop filters and concluded they all have colour casts except for the Lee. I have a Lee filter holder so want to stick with them. Also, the price is similar, actually.

I take your point about using the dark end of ND grad filters to achieve a ND effect. I have used this trick, and it works. So much better to have the full 10 stops on one piece of resin, though.

I've decided to order and wait.......

Thanks for all your comments, everyone.

Regards

[AlexeyD]

Hi TimH
The link you gave advertised the B&W filter. The new magazine, Advanced Photographer did a survey of 10-stop filters and concluded they all have colour casts except for the Lee.

Not to disappoint you but their tests were done on ND Grads - Lee is known to be well tested by various photographers and neutral in the exposures you are likely to make with those ND grads (i.e. not very very long exposures). This cannot really be applied to all other NDs albeit made by the same manufacturer. Big Stopper is known to give a slight cold cast and it gets more pronounced as exposure gets longer. Lee tests their filters manually and measures densities and neutrality on each of them individually but they still fall within some tolerance limits. I also doubt that they measure neutrality using very long measuring times on their equipment to check if any casts accumulate as this will hold up the whole production line. Their casts are less noticable then anybody else's though in long exposures. B+W 10 stop ND also gives a warm cast which may or may not be desirable if you use it for colour photography.

[dave_whatever]

Big Stopper is known to give a slight cold cast and it gets more pronounced as exposure gets longer.

This sounds a bit dubious to me. Surely any difference in colour cast perceived in photos would be a function of sensor/film response to long exposures, not the filter somehow magically changing strength during the exposure. Unless I'm going crazy, how can a filter give a different colour over different exposure times?

[AlexeyD]

Big Stopper is known to give a slight cold cast and it gets more pronounced as exposure gets longer.

This sounds a bit dubious to me. Surely any difference in colour cast perceived in photos would be a function of sensor/film response to long exposures, not the filter somehow magically changing strength during the exposure. Unless I'm going crazy, how can a filter give a different colour over different exposure times?

The filter is dense, measuring its neutrality and density is done in a finite amount of time (the measuring equipment shines the light through and the sensor measures the qualities of light on the other side). This measuring is done withing the acceptable margins of error. The problem is when you increase your exposure, those margins will grow and error will accumulate resulting in a stronger casts. This has nothing to do with the sensor/film (well the cast recorded will be different for different films but that's the colour film property). If you would want a truly neutral filter say on 40 mins exposure, producing this would mean that it has to be dipped, dried, then placed in the measuring equipment for 40 mins then back again to correct for inequalities. Which will take an awfully long time to produce each of them - they would cost a fortune. Then the dipping dye has to be maintained more neutral (with greater control over its chemical properties) which makes it also more expensive.

The Lee ND Grads are also not truly neutral in very long exposures - the problem is though they are quite weak to test in daylight conditions where you can see the cast more easily. You can still setup a test with grey card in a very dark room taking Lee ND 0.9 grad or something like that for say a 40 mins exposure - the cast will be slightly bluish/cold (that's the property of the dye Lee is using). You would need of course to take 2 long exposure shots - one with ND and one without and if using digital set WB for both based on the one taken without ND.

[Tony B]

Thank you for your interesting posts, AlexeyD.

The Advanced Photographer article I referred to was in either the first or second edition, several months ago, not the ND report recently published. They measured the actual light stopping power of several competing 8-10x filters. Interestingly, apart from the reported colour casts, all filters fell short of their claimed light stopping power by typically half a stop. I can't check the details; I no longer have access to the magazine.