View Full Version : Neutral Density Filter Recommendations Please


Peter Moretti
July 12th, 2007, 03:08 AM
I should be getting my HV-20 next month and want to shoot wide open as much as possible, to get used to its shallow DoF capacities at different distances from the subject.

Since the HV-20 has a max shutter speed of 1/2,000th, I imagine some ND filters will be needed, esp for outside shooting.

Any recommendations on brands, strengths and how to best use ND filters?

BTW, I'm thinking of getting setpup adapter to go from 43mm[correction] to 52mm. This way I can buy a more standard size filters, that could even be used on a normal still camera lens attached to an adapter (thinking down the road).

Thanks a lot as always!

Peter

Mike Dulay
July 12th, 2007, 08:58 AM
HV20 has a 43mm filter thread, the HV10 uses 37mm.

Thomas Barthle Jr.
July 12th, 2007, 09:23 AM
I am by no means a professional, but recently read a thread about using 2 linear polarizers. I can't find it, but basically with one fixed and the other rotating, you can get a "variable ND filter" effect. WHILE IN CINEMODE AND 24P, the thread also says if you cover the lens for total darkness, lock the exposure, and adjust it to -11, that will give you:

iris-1.8
shutter-1/48
gain-0

Then use the polarizer as a "like" iris control. I hope I explained this well.

Thomas

Thomas Barthle Jr.
July 12th, 2007, 09:24 AM
I would suggest 55mm filter minimum to keep them out of the frame. This is the standard threading for the Canon 50mm.

Peter Moretti
July 12th, 2007, 02:44 PM
I would suggest 55mm filter minimum to keep them out of the frame. This is the standard threading for the Canon 50mm.Thomas, I'm pretty set on using a Nikon 50mm, that has a 52mm filter size, as my first adapter lens.

Oh and you explained using the two filters perfectly. I imagine it will have a different effect than using an ND if photographing through glass or with refelcted light. But it would be worth a shot.

Pieter Jongerius
July 12th, 2007, 03:41 PM
Hi Peter,

have you heard of the 2 built in ND filters? There's a thread on that somewhere here. Those built in ones may save you the expense and hassle of external filters, but you can't control them directly, I think they engage automatically.
What's worse: adding an external one may cause the camera to disengage its own ND filter, so there would be no effect of putting it on :))

I have my HV20 for some time now, and I suspect the NDs are used even before shutters get fast / iris gets closed, because motion signature and DOF are pretty constant in low to moderate light conditions. In my perception.

Much speculation here, but you have to start somewhere...
regs,
Pieter

Thomas Barthle Jr.
July 12th, 2007, 03:49 PM
I ordered a linear polarizer, my father had one already in excellent shape. Again, I am no way a professional (just a hobby for now) and can't justify spending all that money on multiple filters.

The reason I went with the 55mm is because 1) I already had one 2) I have a 43mm uv on the front of my HV20, which made the polarizers stick out more. You can always use a step-up ring from 52mm to 55mm if you need, you can't really step-down.

Thomas

Charles Papert
July 12th, 2007, 04:57 PM
Just remember, gents, that while a polarizer does function as an ND6 (cutting two stops), it also has a specific effect which is to polarize light! In a run and gun situation, if you don't get into the habit of regularly rotating it to check its effect, you may end up doing unwanted things to the image, such as killing the reflections in water or grass/trees which can "deaden" the look somewhat, or render surfaces that might already be polarized like sunglasses or cel phone screens completely black.

Thomas Barthle Jr.
July 12th, 2007, 05:30 PM
This is true. I, however, will be using this in a project in which I will be doing a lot of air-to-air stuff. This will help avoid blown out sky without underexposing the Stinson aircraft we will be documenting.

Charles Papert
July 12th, 2007, 05:41 PM
It can't hurt, as long as you are flying with the sun at your side!

Thomas Barthle Jr.
July 12th, 2007, 06:01 PM
Yeah. My father is a pilot and we are going to experiment with other aircraft before the big flight. Sorry for off-subject post.

Peter Moretti
July 12th, 2007, 10:06 PM
Hi Peter,

have you heard of the 2 built in ND filters? There's a thread on that somewhere here. Those built in ones may save you the expense and hassle of external filters, but you can't control them directly, I think they engage automatically.
What's worse: adding an external one may cause the camera to disengage its own ND filter, so there would be no effect of putting it on :))

I have my HV20 for some time now, and I suspect the NDs are used even before shutters get fast / iris gets closed, because motion signature and DOF are pretty constant in low to moderate light conditions. In my perception.

Much speculation here, but you have to start somewhere...
regs,
PieterHave you noticed if Portrait Mode uses the widest possible iris, or just a wider than usual one?

Also, couldn't I just manually set the iris to 1.8 and the shutter speed to 1/48th (for example) and see if the meter is in range. If it's reading over-exposed, then just start piling on the ND filters?

In the beginning, I would like to shoot wide open as much as possible. Edge resolution I could really care less about; I actually like some vignetting and corner softness. (Hopefully I won't be eating these words.)

Thanks for your help.

Thomas Barthle Jr.
July 13th, 2007, 08:34 AM
That would work. However, you can't truly manually adjust both settings. If you have a miniSD card in the camcorder, you can half click the photo button to view your iris and shutter. Just lock the exposure and move it up and down until you have to right settings.

Thomas

Pieter Jongerius
July 13th, 2007, 01:54 PM
Have you noticed if Portrait Mode uses the widest possible iris, or just a wider than usual one?

Also, couldn't I just manually set the iris to 1.8 and the shutter speed to 1/48th (for example) and see if the meter is in range. If it's reading over-exposed, then just start piling on the ND filters?

In the beginning, I would like to shoot wide open as much as possible. Edge resolution I could really care less about; I actually like some vignetting and corner softness. (Hopefully I won't be eating these words.)

Thanks for your help.

I also like to shoot as open as possible, however I never really tested this. I think the cam itself has a tendency to leave the iris open as much as possible (and even use its NDs for that matter). Portrait mode should do that even more.

About how to semimanually control the iris/shutter: others have much more experience, I saw some threads on that. Anyone?

Finally the optical quality, I tested this a bit. I noticed quite a lot of vignetting at full wide (visible as brightness falloff in vegas video scopes), but no edge softness. There was considerable edge softness at full tele however.

Pieter Jongerius
July 13th, 2007, 02:09 PM
Alright, here goes: I think I'm still on topic if I ask the following...

I read from the responses that many people are interested in external ND filters, even for the HV20. I seem to be the only one (cry ;) to mention te built-in ones in relation to external ND filters.

If you consider the built-in ones and some of the stuff I wrote above: Why do you still want to use them? No, honestly :))

tnx
Pieter

Peter Moretti
July 13th, 2007, 02:18 PM
Alright, here goes: I think I'm still on topic if I ask the following...

I read from the responses that many people are interested in external ND filters, even for the HV20. I seem to be the only one (cry ;) to mention te built-in ones in relation to external ND filters.

If you consider the built-in ones and some of the stuff I wrote above: Why do you still want to use them? No, honestly :))

tnx
PieterPieter,

From my perspective, I imagine there are times when the built in ND's are not strong enough, so I'm looking for a way to add even more ND w/o disengaging the built in ones.

But please realize that your posts were much appreciated! :) :)

Pieter Jongerius
July 13th, 2007, 02:43 PM
1st of all-Many thanks, wasnt worried...just yet :)

To take it one step further... assuming the built in NDs are engaged "when needed" according to the cam, adding an external ND filter would probably take away that "need". I can see no other way. You would have to go ND10 or something to compensate for the disengaged internal NDs!

Anyway, I'm guessing that... but if you read this http://www.dvinfo.net/conf/showthread.php?t=81516 for some pretty enhanced ND stuff, you'll get to read this quote from the patent by Mike Brown (thanks mike)

Combinations of the densities of the ND filter and the F-numbers of aperture control at individual EVs will be explained below with reference to FIG. 11B. In the region where the EV is 2 (inclusive) to 8 (exclusive), the shutter speed lowers in accordance with each EV, but the F-number of aperture control is fixed to F2 as an open-aperture F-number, and the number of ND steps of the ND filter is also fixed to 0. That is, the transparent portion 151a shown in FIG. 2 of the ND filter 151 is used in this region.

In the region where the EV is 8 (inclusive) to 11 (exclusive), the shutter speed is continuously variable from 1/60 to 1/125 sec, the F-number of aperture control is continuously variable from F2 to F4, and the number of ND steps of the ND filter is fixed to 0.

When the EV is 11 or more, the F-number of aperture control is returned from F4 to F2, and the number of ND steps of the ND filter is switched from 0 to 2. (Referring to FIG. 11B, the switching points of the F-number and the number of ND steps are different. In practice, however, the F-number and the number of ND steps are simultaneously changed.) That is, in this stage, the uniform-density portion 151b having an optical density of 0.6 shown in FIG. 2 of the ND filter 151 is used.

In the region where the EV is 11 (inclusive) to 14 (exclusive), the shutter speed is continuously variable from 1/125 to 1/250 sec, the F-number of aperture control is continuously variable from F2 to F4, and the number of ND steps of the ND filter is fixed to 2.

When the EV is 14 or more, the F-number of aperture control is returned from F4 to F2, and the number of ND steps of the ND filter is switched from 2 to 4. That is, in this stage, the uniform-density portion 151c having an optical density of 1.2 shown in FIG. 2 of the ND filter 151 is used.

In a region where the EV is 14 (inclusive) to 17 (exclusive), the shutter speed is continuously variable from 1/250 to 1/500 sec, the F-number of aperture control is continuously variable from F2 to F4, and the number of ND steps of the ND filter is fixed to 4.

In a region where the EV is 17 (inclusive) to 19 (exclusive), the shutter speed is continuously variable from 1/500 to 1/2000 sec, the F-number of aperture control is fixed to F4, and the number of ND steps of the ND filter is kept fixed to 4. The exposure control diagram described above is applied to single-shot photographing or photographing of the first frame in continuous photographing.

If this is accurate, thats the definitive answer. The cam keeps the iris as open as possible and adds up to ND4.

Colin Gould
July 13th, 2007, 07:16 PM
I'm a bit confused w/ the internal ND issue.
In regular P or auto modes, my HV10 still tends to be overexposed a few stops, unless I go to Av mode and crank the aperture all the way down, to like 8.0...
I lose any artistic control over aperture/DOF of course (luckily I don't normally care, but)...
shouldn't the ND filters help that?

I'm planning to buy a Tiffen 3filter kit w/ UV/MC filter (help some w/ sky/haze a bit), as well as ND 6, so that (if I want) I can get back Av control...
will the internal camera filters/controls defeat this?
Anyone comment on this particular kit/brand and how well it works on the HV10? I seem to recall someone commenting about chrome rings reflecting on closeup subjects sometimes :)
http://www.bhphotovideo.com/c/product/153144-REG/Tiffen_37DFK3_37mm_Video_Intro_DLX.html

Wish the kit came with a circular polarizer rather than FL-D (I use white balance control for that), but oh well...

Pieter Jongerius
July 14th, 2007, 03:00 AM
...shouldn't the ND filters help that?...
...will the internal camera filters/controls defeat this?


Well, translating all the tech talk above: The reason why you feel the image is overexposed is because the camera 'likes' it that way. It is not a technical limitation. It will do everyting in its power to keep it 'overexposed', unless you lower exposure by manual override using the joystick or set a brightness-1 in the menu settings (or indeed do a forced Av or Tv). This is exactly why simply adding ND almost certainly won't work. The cam will reduce its own ND, go 1/48th, open iris, beg the light to come in, even on a sunny day if it thinks it's needed and your skies (and mine :) will blow out anyway.

In practice, I always have the brightness setting at -1 and if needed add EV-2 with the joystick.

regs
Pieter

Peter Moretti
July 14th, 2007, 04:22 AM
1st of all-Many thanks, wasnt worried...just yet :)

To take it one step further... assuming the built in NDs are engaged "when needed" according to the cam, adding an external ND filter would probably take away that "need". I can see no other way. You would have to go ND10 or something to compensate for the disengaged internal NDs!...Pieter, but it's entirely possible, in some lighting conditions, to want a shutter and F stop combination that the built in ND filters aren't strong enough to prevent from overexposing. In that case, the camera won't disengage its built in ND filter if I put my own in front of the lens.

Pieter Jongerius
July 14th, 2007, 06:38 AM
So true... I guess that that thought didnt enter my mind because of the lack of a proper M mode on the HV20. It is totally feasable to trick the cam into locking in an overexposed situation and then add your ND. There's my answer, thanks!

Thomas Barthle Jr.
July 14th, 2007, 03:52 PM
About how to semimanually control the iris/shutter: others have much more experience, I saw some threads on that. Anyone?

Check this out:http://www.dvxuser.com/jason/hv20/

Peter Moretti
July 16th, 2007, 07:40 PM
Thomas, thanks, that's a very useful link!