Additional ND Filter for Nokton 25mm?

F

filmguy123

Veteran
I will be shooting a lot of outdoor documentary work on a Nokton 25mm (I will be in India in a couple weeks). I am wondering if there is a good, simple ND Filter I can attach to the glass (in addition to the AF100s ND filters). Perhaps in small increments so that I can fine tune the image. I would like to be able to shoot between f/.95 - f/2.8 for most shots and I have a feeling even at ND4 on the AF100 I might be overexposing.

Any recommendations for a gentle 52mm threaded ND Filter?

Also, would I be able to use a UV Filter on the lens + add the ND Filter on top of that? Or would the ND filter be in lieu of the UV Filter?
 
If your lens has a thread on the front...there are many ND filters available in increments .3,.6,.9 (1, 2,3 stops incrments).

There are even Variable ND Filters.

Whatever..dont buy cheap. You get what you pay for. Like lenses.

You then need to decide how you will mount any lens shade / hoods.
 
Do you have experience in what pairs well/what I'd need for daylight with the 25mm? I don't want to get one too strong.

What are the increments on the AF100? I'm wondering if I could get one that, when attached, would serve as something in between ND1/2, 2/3, 3/4, or add just a little bit past what ND 4 offers?

Can I put UV Filter + ND Filter on end of lens?

And do they make variable ND Filters that go from totally clear to .3 to .6?
 
You will find a single stop ND (.3) to be very handy in combination with the built in NDs. Most cameraman carry them all though because not all cameras have built ins.

FWIW: The built in NDs are actually designed for exterior shooting and can be a bit of a PIA in the studio. Its easy to get caught between the increments. Thats where an add on comes in. .3 or 1 stop is the one I use mostly. ( in studio)

Check your manual for the increments because they are not the same as .3 to .9 as per a "true" ND filter. They are described differently. and are much "coarser" increments.
 
Thank you for the help! I checked the Barry Green manual and the AF100 ND filters are about the following:

ND1 - N/A
ND2 - 0.6 (2 stops reduction)
ND3 - 1.2 (4 stops reduction)
ND4 - 1.8 (6 stops reduction)

So I think picking up a .3 ND Filter would be a good purchase as it would give me all increments (1-7 stops) of reduction when combined with AF100's built in ND Filters.

Just three more questions:

1.) Is it likely for most outdoor work that I would need more than 7-stops of reduction (basically, a 2.1 ND filter) to shoot at f/0.95-f/2.8 on that Nokton? For interview shots?
2.) Can I stack filters on a lens? I literally have never screwed on more than a UV Filter. Can I put on a UV filter, then an ND? Or must I remove the UV to screw on the ND filter? And/or - can I put on a .3 ND and then add another .6 screw on ND?
3.) In the case that I cannot stack. Do they make a variable screw on ND filter with a base setting of NO REDUCTION, that is variable and can be twisted to .3 and .6? Basically, so I could use the ND Filter as a clear filter for lens protection, and then rotate on any ND filters as I see fit?

Thank you again for the help!
 
It's best to minimize reflections caused by parallel glass surfaces by keeping the number of stacked filters to a minimum. There is an optical degradation as well as you're passing light through more material. Your best option is to remove the UV when using a ND filter. You can stack ND filters to get where you need to be, however you're risking the aforementioned issues. It's best to have a 'set' of ND's as Shooter mentions in order to minimize the amount of extra glass in front of the lens. The amount of money spent on a variable ND could buy you a set of standard screw in ND's. You'll probably find that a ND.3 and ND.6 will be all you'll need. Additionally, the variable ND filters (essentially polarizers) can present other issues as well such as uneven image brightness and vignetting under certain circumstances. I haven't used the variable, but continue to read about
these problems, especially when using them for stills.
 
I see, great info. Thanks spotts. I'll remove the UV first, unless I am worried about dust/dirt conditions (will be shooting a lot of 3rd world documentaries)

So how about 2x Tiffen ND Filters for $12 each - a .3 and .6 - think they'll suffice ($25 total)? Or is it wiser to spring for the more expensive B+W NDs for $30/ea ($60) total?

Tiffen filter:
http://www.bhphotovideo.com/c/product/58647-REG/Tiffen_52ND6_52mm_Neutral_Density_ND.html

I bought the MRC B+W as my UV and I figure the NDs will get limited use - only when I can't get a desired wide open shot in daylight or need a weird .3 increment in a sensitive condition. I don't want to compromise image quality, but i also don't want to spend too much on a filter that will see limited use.
 
Tiffen filters have always worked for me. They've been quite good in the past although I haven't purchased any in years. Give them a try and save some money.
 
1.) Is it likely for most outdoor work that I would need more than 7-stops of reduction (basically, a 2.1 ND filter) to shoot at f/0.95-f/2.8 on that Nokton? For interview shots?
Click to expand...

You can test this yourself.
 
Thanks spotts & Shooter! I ended up going with a Tiffen .3 and Tiffen .6 for a total of $25. In conjunction with the AF100's built-in ND Filters, hopefully this should work great.

if I am in a pinch I can add the .3+.6 + ND4 for even more though reduction, though I know I'd get some image degradation by stacking 2 filters.
 
You wont need to stack them.

Select and use an ISO that works for the shoot and your intentions...then use the internal NDs 1st...then externals if necessary.

Do some tests before you go.

BTW - I am not suggesting you use ISO to control exposure shot to shot.

How are you going to "lens shade"?
 
Filmguy....here's a little inexpensive French Flag you may want to take with you. Often if you're shooting alone you can run out of 'arms'. I have this model (14")....and use it all the time to minimize flares. It also is easily stowed in a camera bag. Very easily positioned and invaluable both indoors and out. Order the 19" model if you're using any long lenses. It mounts to the hot shoe on the carry handle.

http://www.barbertvp.com/products-14EZ.html
 
filmguy123 said:
... I would like to be able to shoot between f/.95 - f/2.8 for most shots and I have a feeling even at ND4 on the AF100 I might be overexposing.

Any recommendations for a gentle 52mm threaded ND Filter?

Also, would I be able to use a UV Filter on the lens + add the ND Filter on top of that? Or would the ND filter be in lieu of the UV Filter?
Click to expand...

To meet your goal, without stacking several filters onto the lens at once, get a 4-stop, a 3-stop, and a 1-stop ND. Here's how I calculate that:
An old photographers rule-of-thumb is that if you take the reciprocal of the ISO number as the exposure time, then f/16 would give the right exposure for a sunny day. (Although noon on a clear summer day, with light sandy ground reflecting light on your subject would probably be f/22; but let's ignore that possibility.) So the lowest ISO for the AF100 is 200, and the reciprocal would be 1/200. But you'll probably be shooting at about 1/50, a 2-stop difference from 1/200. So you need to stop down 2 stops from f/16; that would be f/32. Now if you wanted to shoot at f/1.0, that's 10 stops difference from f/32. The built-in filters will give you 6 stops, so you would need to add 4 more stops of ND (if you really really wanted to shoot f/1.0 in sunlight). If it's hazy sunlight, then 9 stops would work, so add only 3 more stops of ND to the already 6 stops of internal filters.

As has been pointed out, stacking multiple filters will tend to degrade the image some, so I would remove the UV when adding an ND (unless in a dusty or wet environment). B+W is a very respected maker of filters, and they have many which are multi-coated, which should reduce degradation. Tiffen, another respected maker of filters, says on their website that their tests show that multi-coating filters doesn't offer anywhere near the benefits that multi-coating lenses provides. Consequently, not many Tiffen filters are offered with multi-coating. Anyhow, I'd say get either B+W or Tiffen, they're both good. :thumbsup:

-- Ken
P.S. -- I'd just get the 3-stop, and if a situation arises where I have to shoot at f/1.4 instead of f/1.0, so be it. And if you're in shade or indoors, you could make a minor adjustment to the ISO setting to get the f/ stop you want. Upping the ISO from 200 to 320 or 400 should not make a noticable difference in video noise. Just remember to black balance and white balance.
 
Reality is...you can do your project without an external ND filter because of the AF100 internal ND feature.

Bet you hardly ever get round to fitting an external in the heat of the moment of documentary shooting.

Other thing I notice in your other post (thread)...variety of lenses. Propbably all with different filter threads! Hassle.

Good luck.
 
Shooter said:
Reality is...you can do your project without an external ND filter because of the AF100 internal ND feature.
Bet you hardly ever get round to fitting an external in the heat of the moment of documentary shooting.
Other thing I notice in your other post (thread)...variety of lenses. Propbably all with different filter threads! Hassle...
Click to expand...

To be honest, I've never used an external regular ND filter since I got my AF100; the internal ND filters are sufficient.
Instead of screw-in filters, I have 4x4 filters for use with a mattebox (so the different lens thread sizes are no problem). I've used my 1-stop graduated ND only once, and my polarizing filter only 2 or 3 times.:huh: I suppose I could have got along without them. Ah, but that mattebox makes a mighty fine lens shade!:) Oh, yes.... and I have a 2-stop ND (from before I got an AF100) which I don't use, but let a friend with a Canon DSLR use.

-- Ken
 
Same here.

In studio ..the mattebox facilitates an easy fit of a 4x4 .3 ND filter. That is our usual requirement to cover the tweens of the internal NDs
 
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