Blackmagic Forum

Does anyone know a brand or where to find a inexpensive IR filter, that can either work with my Cokin P Series filter holder (square filters) or a screw in filter. I'm finding alot of filters that ONLY ALLOW IR light through, but nothing that cuts the IR.

Watch this: http://www.ryanewalters.com/Blog/blog.php?categories=IR
Then go to eBay and search for "IR680"

Square ones (4x4 or bigger) seem to be 200$+, round ones 58mm/77mm/... seem to be around 10 - 30$ if you go cheap...

Yeah I saw that video, it's great, the reason I'm looking into ir cut filters.

Checked ebay, say a ridiculously inexpensive one, for like $10 from Hong Kong. Anyone use one of these?

52mm IR 680nm Filter Infrared Infra-Red Nikon Pentax
http://www.ebay.ca/itm/52mm-IR-680nm-Fi ... 4ab644991d

Make sure you go with a filter that is made out of water white glass and nor resin. Resin filters can distort colors and blur images.

My son, Ben Kadie, is a youth filmmaker who has used some prize money to order a BMCC. I've been helping him figure what accessories to get. Two tricks that I think that I've figured out:

If the lens in the picture is black, it's the wrong kind of IR filter (it's the kind that lets only IR in rather than the kind that keeps only IR out)

Searching for 'IR Cut filter' (no quotes) seems to work

Here is two 77mm filters we are looking at. I have no idea why the prices ($35, $50) are so different:

http://www.ebay.com/sch/i.html?_odkw=ir ... &_sacat=0#
http://www.ebay.com/itm/77mm-Optical-UV ... 27bb4ca101

- Carl
p.s. Ben's film website: http://benkadie.com

Traditionell IR filters and hot mirrors where invented for film. What you want with a digital camera is a "near IR" filter, that cuts out around 680nm.



I use the Heliopan Digitalfilter, BLF 1x, LW -0 religiously and get great results.

http://www.heliopan.de/produkte/digital-video.shtml

Frank

I've also been hearing that a Tiffen T1 is a good choice. I'm planning on getting one of these soon.

Here's a link: http://www.filmtools.com/tit1irfi.html

The magic words of the OP were "inexpensive", which neither the Tiffen nor the Heliopan really are...

I'd get a dirt cheap one first and if that doesn't work for you, get a more expensive one... throwing away 10$ isn't really a big deal...

Why anyone would buy a BMCC and then put cheap crap in front of the lens is beyond me. Why not buy a Gh2 in that case?

arknox wrote:Why anyone would buy a BMCC and then put cheap crap in front of the lens is beyond me. Why not buy a Gh2 in that case?

Well said, Minus the GH2 banter, Better to not have any IR filter than a $10 one off ebay,
You can get the Tiffen ND with IR or just the IR filter, but in most cases none of you will
know the difference seriously, Just go shoot, make videos, have fun, worry later, spend later!

Filters are a fairly large expense, one you should consider wisely, and one that is an investment
like lenses, take your time, save money, and only buy as you need them,
Not having a IR filter is not going to ruin your day, No ND might...But not having an IR won't.

You need ND, IR not so much!
2 cents spent

Is it correct that the more ND you use, the more important an IR filter becomes?

CarlK wrote:Is it correct that the more ND you use, the more important an IR filter becomes?

Yes. In general, ND .9 or more is when you may need an IR cut filter.

Since all my lenses have 77mm or smaller front filter threads, what I've done is put 77mm step-up rings (inexpensive) on all of them, and I use screw-on 77mm ND and other filters (including a Tiffen T1 IR cut filter).It's not as convenient as using flat filters in a matte box, but less expensive to buy. My filters are all Tiffen "water white" glass.

On the subject of popular cinema cameras and IR pollution, this video by Abel Cine is very informative:

Darryl Gregory wrote:Filters are a fairly large expense, one you should consider wisely, and one that is an investment like lenses, take your time, save money, and only buy as you need them,

Agreed. Same for lenses and adapters and rigs and other gear. Obviously if you know you can find the same quality and fit cheaper, you may want the cheaper product, but usually "you get what you pay for" is true. After watching that Abel Ciné video on filters on the BMCC sensor, the best screw-on filter in their comparison is the Tiffen IR ND family. There are also others that are very good, but it looked like Tiffen Sets the standard for our sensor.

Rick Lang
Sent from my iPad using Tapatalk HD

Can you screw the IR Cut filter on the lens and t h e n the ND-filter? Because this way I could just get a 77mm IR Cut-filter, other way round would need a 82 mm if you have to screw the IR cut on top of the ND filter.

Thanks for your input. And thanks for pointing towards good experiences with the Tiffen one!

gmf wrote:Can you screw the IR Cut filter on the lens and t h e n the ND-filter? ...

As far as I know, yes: It's OK to put the IR cut filter on the lens first (closest to the lens), and then put your ND filter on the outside of the IR cut filter. I've used Tiffen's T1 and ND filters that way & it seems to work.

The advantage of using combination filters that are ND + IR cut in one filter is that this reduces the chance for flares & reflections which can be caused by using multiple filters, especially in back-lit scenes. Of course, combination filters are more expensive ... another in a series of compromise/no-compromise decisions to make.

It helps to use quality, optically-coated, "water white" glass filters, and if necessary to prevent unwanted flares, flag the lens (using a french flag, matte box, or a black flag on a stand).

Thanks a lot, Peter!

I already own two Fader-NDs so I can't shelve out money on those combination-filters.

Thanks for the advise guys.

Looking into the Tiffen IRs.

Question though, is 77mm the standard for screw in filters? Do the Tiffen filters come in other sizes? I got the two slrmagic mft lenses, the 12mm, and the just released 25mm T0.95 and they are 52mm screw in and 49mm screw in respectively.

My 25mm came with a 49-77mm adaptor ring, combined with the fact that the Tiffen screw in filters are 77mm, was just wondering if this is standard.

I'm used to cam assisting with the traditional matte-box 6x6 filters, which I never had to own luckily :> So I haven't used screw-in filters much.

Jim DeLuca wrote:... is 77mm the standard for screw in filters? ...

No, screw-in filters come in many different diameters.

77mm or less is common for DSLR lenses, but there are exceptions.

And flat filters come is a variety of sizes, too.

For example:
http://www.bhphotovideo.com/c/browse/Ro ... 4207499377

The combo ND and IR is only $10 more than the IR alone:

http://www.bhphotovideo.com/c/product/6 ... nsity.html