UKC

I'm after a Neutral Density filter. Looking on Amazon I can spend between the extremes of a few pence to mortgaging my soul just for a piece of tinted glass.

Could somebody please explain what I should look for, or what brands I should consider, when choosing a round ND filter?

My lens has a 52mm diameter thread, however I have an expansion ring that goes to 72mm, which means that I'm after a 72mm diameter filter. I read somewhere on the web that it was a good idea to get a bigger filter than the lens to help cut out vingetting . I don't know if this is an old wives tail or somebody having a good laugh at my expense but the theory sounded plausible to me.

In reply to The Lemming:

I got these after reading a few reviews:
https://www.amazon.co.uk/Neutral-Density-Filter-Gradual-Adapter/dp/B009GTM6...
The filters are all plastic, I've had a bit of a play with them but not had a great deal of success yet (lack of going anywhere with running water since I acquired my tripod has meant I've not been able to make much use for my intended purpose). I've got a Sigma 10-20mm which has an 82mm filter thread, there is definitely considerable vignetting on the image when I use it at 10mm (unless I twist the filter around 90 degrees meaning I can only shoot in portrait with the graduated filters fitted).
If you want to see how severe it is at a couple of different focal lengths drop me a message and I can fish the filters out.

In reply to The Lemming:
Tried a cheap ND filter off amazon for my cokin z pro set up, wasn't too impressed with it and finally got a lee big stopper, for less effect I have a cokin nd that drops 4 stops.if you have the space the cokin/lee filters are very flexible but unless you go up too the 150mm set up (very expensive) vigneting will always be a bit of a problem at the widest setting. I always loose a couple of mm, so on my tokina 12-24 I will set it at 14mm with the filter holder on (20mm equivalent )and have no problem with vigneting.

In reply to The Lemming:
If you think you're going to want positional ND grads in the future (generally landscape work though other uses too) then bite the bullet now and go for the Lee system.

A good ND screw-on filter shouldn't suffer from vignetting problems. I would guess £25+ for one of those, but you've probably a much better idea than I have.

Edit: btw, 2nd hand lee system kit is usually very good and much cheaper, particularly the foundation set. It is good quality robust materials, and photographers (generally!) are a timid lot.

In reply to The Lemming:

OK, next question for a round ND filter. Is it better to get a variable ND filter or a bog standard ND filter?

My brain hurts from reading reviews from people with questionable technical expertise.

In reply to The Lemming:

Depends what you want to use it for? I would have thought if you're looking to get motion blur (water, clouds, traffic, whatever) in normal daylight conditions you'd want something pretty dark. Get the darkest you think you need, and then you can always (to some extent) work backwards from there. I can't see a variable being the same quality (including vignetting problems) as a standard ND for a given price.


Sorry to add to the pain!

In reply to Jon Read:

Yes, my bad.

I forgot to mention that the filter would be for video where I can not adjust the shutter speed but I still want a large apature to separate my subject from the background.

In reply to The Lemming:

Lee ND filters, Simple as that really.

In reply to The Lemming:

Ah! In which case I cannot offer any advice, I can't even figure out how to properly shoot video on my camera!

Unless your scenes are pretty constant light, I would have thought it would be very difficult to compensate dynamically with a variable filter for changing brightness?

In reply to The Lemming:
http://www.wexphotographic.com/buy-lee-little-stopper-bundle/p10002554

the big stopper might be to much for what you are looking for, the little stopper combined with another ND filter might give you the flexibility for video work or a combination of the below. Obviously stacking filters can effect the image quality especially with their propensity to collect smears and finger prints (always clean your filters when you get back, nothing worse than desperately trying to clean a dirty filter as the magic light disappears )

or alternatively some cokin filters

http://www.wexphotographic.com/buy-cokin-z-pro-full-nd-kit/p1606790

married to an cheap Amazon filter holder(I would get a Cokin or Lee set up but they are all interchangeable 100MM filters)

Cokin filters are pretty good and reliable but from my limited experience the Lee filters are a notch above

In reply to The Lemming:

What lens are you using . How wide it goes is an important factor in what system you will require.

In reply to john1963:

I'm using a micro four thirds camera with a zoom lens that goes from 12mm to 35mm. On a full frame this would roughly be equal to 24mm to 70mm, or there about.

In reply to The Lemming:

Have you got a polariser? That will double as a 2 stop ND for starters, which is a useful amount for opening up in bright light. Variable NDs are basically 2 polarisers stacked so that density varies from 2 to up to 20 stops.

For grads I ponied up for Lee system years ago and haven't regretted it, but the hi-tech ones are a decent alternative. They scratch easily so if you do go Lee look after them with a proper case and triple pouch-wrap thing.

>it was a good idea to get a bigger filter than the lens to help cut out vingetting .

True, but it only matters for very wide lenses <28mm equiv. For teles you can even get away with filters smaller than the filter ring.

In reply to Adam Long:


2 stops?? Really? My CPL doesn't seem to give anywhere near that, and of course it's only reflected light that's attenuated anyway.


Yes, the vignetting thing is only applies to ultra-wides.

In reply to Toerag:


+1.5- 2 stops has been the recommended filter factor for polarisers for at least fifty years. On digital you can of course compensate less and boost in post, but I've always needed to use +2 on film.


No it isn't, maybe read up on it. Are blue skies, for example, reflected light?

In reply to Adam Long:

Yes - reflected off particles in the atmosphere. How else do you explain the colour? All the gases that compose air are colourless.

In reply to The Lemming:

While reading and watching many, many, many reviews I read about using a ND Filter to remove people from urban scenes.

Anybody ever done this before?

In reply to The Lemming:
I have had the ND remove people from landscapes that I have shot this was more of a side benefit although I did wait till they started moving before hitting the shutter (once they had finished their selfie)

In reply to The Lemming:

I do it all the time for crag shots and for touristy (Tre Cime etc) landscapes.

A little long exposure video I made a while ago: youtube.com/watch?v=gwsMTRovXEQ&

In reply to James Rushforth:

I've been looking at a few YouTubes raving about Breakthrough filters but I just could not trust or believe the Talking Heads.

Now that I've seen you rate their filters, I shall give them a punt.

BTW, have you ever used any Variable ND Filters, and if so did you find any image quality problems with them when using wide angle lenses down to around 24mm or less?

Like the video

In reply to Toerag:

Right, agreed, so when you stated that 'only reflected light is attenuated', like it was a big limitation, what exactly did you mean? What are you photographing that isn't reflected light?

And even if you photographed the sun with a long lens, (direct light yes, not reflected?) would a polariser not 'attentuate' the light? Yes it would, and crossed polarisers would attenuate it almost completely.

In reply to The Lemming:

A bit of welding glass held on with some 'lacky bands?

I've actually got a piece that fits in my Cokin holder, it's about 10 stops but it's so green that you need a custom white balance to get anything close to usable.

In reply to James Rushforth:

I took a punt and placed an order for a 6-stop ND filter from Breakthrough. Done a bit of guessing and wishful thinking using the Sunny 16 rule to try and guestimate the amounts of stopping down.

Hopefully I have my sums right. I'd be most grateful if somebody on the forums with bigger brain cells than me can tell if I am close by thinking that on a sunny day with an aperture of f2.8 and a shutter speed of 1/50th would need to be stopped down by between 5 and 6 stops to get my footage accurately exposed?

I was thinking that a 10-Stop ND filter would be too much for a sunny day.

Just got to be patient and wait on the Backorder now. No date but I'm hoping by the end of January.

In reply to Adam Long:


Yes, but not all reflected light is the same is it, or polarisers would have the same attenuation effect regardless of orientation.


Agreed.

In reply to Toerag:

Anybody else clueless to what this argument is about?

In reply to Toerag:


In terms of overall light loss the attenuation effect is the same regardless of orientation - around 2 stops.

A noticeable 'polarised' effect only arises in certain conditions - blue skies or shiny surfaces - and with camera and polariser at certain orientations. In overcast light, with the sun inline with the camera, or by rotating the polariser to 'minimum' you essentially have an overall 2 stop ND - which was the original point.

What I think you've been trying to say is that polarisers affect reflections. Well yes they do, but not always and that's not all they do.

In reply to The Lemming:

If your sunny f16 rule 'version' is 1/100 f16@ISO100, then yes, it is 6 stops to get to 1/50 F2.8 ISO100:

f16-f11-f8-f5.6-f4-f2.8 = 5 stops
1/100-1/50 = 1 stop

Each stop down will halve the amount of light reaching the sensor, so a six stop ND will only let through 1/64 of the light.

In reply to ChrisJD:
Thanks for the confirmation. I spent ages and ages trying to work something so simple out.

I'm looking forward to my new filter so that I can try some videoing outside at 2.8.

Yay