Infra-red filter for on-camera flash

[jaylynd]

Has anybody heard of covering the on camera flash with and infra-red filter to

avoid blinking issues when using remote flashes in Commander mode?

 

If so, can you let me know what material is used for such a purpose and how well

it works.

 

Cheers,

Jason

[pico_digoliardi]

1. The flash doesn't cause people to blink. It catches them when they are blinking. See, the flash is less than 1/1000th of a second. The human eye cannot respond that fast.

 

2. Your sensor might not be sensitive to IR light sources.

 

3. IR is very mean to skin; it emphasizes veins, anything blue near the surface of the skin.

 

4. IR as direct-flash tends to go into clothes and right back, making some clothes semi-transparen.

 

...and there is more.

 

Are we cool with the idea of forgetting that idea now?

[john schroeder]

Yes! Nikon makes a clip-on IR pass filter for the SB-50dx and also a clip on IR pass filter for the on camera speedlights. If you call Nikon's parts department you should be able to order the filter for the on camera speedlights. Nikon's new macro flash also ships with this filter. 1-310-414-8107 is the phone number for Nikon USA's parts department. I don't know the part number for the pass filters but they should be able to look it up.

[john schroeder]

SG-31R is the part number for the on camera filter. Nikon refers to it as "SG-31R IR Panel for Built-In Flash"

[fourfa]

it's not the flash during the exposure that causes the blink, you're right in that it happens way too fast for human reaction time. It's the pre-flashes, during which the master communicates with the remotes and establishes power settings, that cause subjects to blink or worse.

 

two easy options: use flash lock to pre-meter, then trigger when you're ready, or tape some kind of IR filter material over the master flash head. It'll still communicate with the remotes, but the subject will barely see any visible flash. The common material is unexposed, process E6 slide film. One thickness will leave a dim deep red flash, two thicknesses will be invisible to the eye but may reduce range. I never had a problem triggering a SB600 from my D70 with two thicknesses in a single room.

[stephen hazelton]

Are you intending to take the picture by IR? Or just use the on-camera flash as a master unit with no actual flash exposure from it?

 

The flash is real short, but there's got to be some delay between the time the finger moves and the shutter fires- is that long enough to develop a blink? I assume not, but have never heard.

 

Lee makes an IR filter that is fairly cheap that could possibly be cut down and used in a flash- check B&H's site.

 

IR being mean to veins and all- not applicable as long as you're not exposing for that IR- if you are, then you're also looking at B&W photography.

[fourfa]

oh and the Nikon accessory mentioned above is available <a href="http://www.bhphotovideo.com/bnh/controller/home?O=WishList.jsp&A=details&Q=&sku=410445&is=REG">here</a>. $12. I prefer the E6 film, simply for being less bulky in the camera bag.

<p>

and just in case anyone doesn't get it (as the first respondant didn't get what the question was), this only deals with the communication flashes between master and remotes. It's not lighting the subject with pure infrared; in fact the commander contributes nothing to the exposure (the one exception is with macros of shiny objects, in which case you use the same trick to block unwanted reflections from the master). And the remotes are obviously sensitive to IR, as the IR-only SU-800 commander proves.

[fourfa]

whoops, should be "unexposed, <b>processed</b> E6 slide film" in my first post.

[chris_vincent2]

The pre-flash can definitely cause blinking and directing flash at the subject, especially small children can unsettle them. The plug-in IR filter is designed for the close-up kit so I'm not sure what range it has.

 

My first solution to this was to use and SB800 as a commander and point the flash somewhere where it didn't pre-flash directly at the subject. There is still enough light to trigger the remotes - indoors at least. But this is a waste of a flash.

 

I now use the SU-800 and this solves all my problems. The IR preflashes are visible within the unit if you look closely but this does not affect the subject. Based on this experience a simple IR filter over the on-camera flash should work fine. It doesn't need to be too strong, just so long as it takes the 'sting' out of the flash.

 

In short, I think the on-camera flash works great as a commander for all cases except where portrait subjects are looking directly at the camera.

[shineofleo]

Interestingly, yesterday I just read this on <Advanced Photography>. This small filter for flash gun turn the flash into a IR version one.

 

It is not a trigger system, just a filter for flash.

 

Where can I buy such a toy?

[mark_sirota1]

I use the SG-3IR, as described above. I got it <a href="http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=410445&is=REG">at B&H</a>. Exposed film works too, I used that before I got the SG-3IR, but it's not as quick to add and remove. The range seems quite good, I've never exceeded it.

<p>

As you can see in the attached photo, without the SG-3IR, the on-camera flash creates a visible catchlight even when it is set to "--" (controller only). (My son was insisting that I had to flip up the SG-3IR. He's a control freak. :-))

<p>

Note that B&H, Adorama, and the post above all mistakenly call it the "SG-3<b>1</b>R" instead of "SG-3<b>I</b>R" (it ends in "IR" as in "InfraRed").<div></div>

[jaylynd]

Thanks everyone for your knowledgable responses. I believe I got the answers I needed. It's the pre-flashes in TTL Commander mode with subject looking at the camera that I am worried about.

Andy, I think the E6 film idea is what I was looking for. I'll try that first, and move on to the Nikon attachment or SU-800 if all else fails.

I'll report back any usefull findings.

Cheers,

Jason

[joseph_wisniewski]

A minor quibble, but the part number is actually SG-3IR (letter 'I', not number "1"). It's the successor to the SG-2.

[joseph_wisniewski]

Mark, didn't catch you post. Sorry.

[jamespjones]

For what it is worth; Nikon's marketing book lists it as SG-31R IR.