IR and Flash Speedlight

[Francis247]

Hi All IR experts,

Not sure if this is a stupid question, but just want to discuss about this topic and hopefully you all can share your view and knowledge.

For normal photography (let's say for portrait), even in broad daylight, we may need to use Flash to do fill-in to eliminate shadows. My question is, when doing IR, what will be the effect if we use flash speedlight, will it works like a normal flash?

I did an internet search but all they shows is IR flashlight or IR filters for flashlight (it is those torch-type flashlight, not speedlight) which looks very interesting.

Hopefully someone can share their view on this. Thank you very much.

[teerex]

Originally Posted by Francis247 Hi All IR experts, Not sure if this is a stupid question, but just want to discuss about this topic and hopefully you all can share your view and knowledge. For normal photography (let's say for portrait), even in broad daylight, we may need to use Flash to do fill-in to eliminate shadows. My question is, when doing IR, what will be the effect if we use flash speedlight, will it works like a normal flash? I did an internet search but all they shows is IR flashlight or IR filters for flashlight (it is those torch-type flashlight, not speedlight) which looks very interesting. Hopefully someone can share their view on this. Thank you very much.

Francis,

From what I know:

1. Those torch type flashlights work for IR shoot at night. But then they may be short throw and of low intensity, the long throw more powerful ones are very expensive.

2. You can mod an external speedlight to fire IR spectrum of light. There are a few people here who already have it. Not difficult to mod if you have the materials. But you need a modded camera for this option.

3. IR lights like those used by video cams also allow you to shoot IR stills. I have used it once from Dennis, works. But then it's also the issue of distance.

[Francis247]

Originally Posted by teerex Francis, From what I know: 1. Those torch type flashlights work for IR shoot at night. But then they may be short throw and of low intensity, the long throw more powerful ones are very expensive. 2. You can mod an external speedlight to fire IR spectrum of light. There are a few people here who already have it. Not difficult to mod if you have the materials. But you need a modded camera for this option. 3. IR lights like those used by video cams also allow you to shoot IR stills. I have used it once from Dennis, works. But then it's also the issue of distance.

Hi Teerex,

Thanks for sharing the information.
Thought of getting one of those IR Flashlight to try out the effect.
As for the mod external speedlight, I was thinking, the speedlight comes with some Gel Filters that you can put over the speedlight for different colour effect, not sure if there is any filter for IR.

[deadpixel]

Originally Posted by Francis247 Hi Teerex, Thanks for sharing the information. Thought of getting one of those IR Flashlight to try out the effect. As for the mod external speedlight, I was thinking, the speedlight comes with some Gel Filters that you can put over the speedlight for different colour effect, not sure if there is any filter for IR.

Hee! Hee!

You can try, but it will be an expensive lesson...the heat from the speedlight is so intense that it will melt and warp the gel IR filters.

What I did when I started experimenting was to buy a Stofen Omnibounce, cut off the front of the Omnibounce and cover the whole omnibounce with developed-unexposed film. This cut off the visible light but allowed a modified camera to capture photos in complete darkness. I've photographed people in the dark without them being aware.

For a slightly more advance version, I got a piece of ELP filter, cut it and glued the pieces together to form an IR omnibounce.

To go completely to the extreme, you could modify the flash with an IR flash bulb. Not sure if these are readily available but know that they exist.

Cheers,
Matt

[Francis247]

Originally Posted by deadpixel Hee! Hee! You can try, but it will be an expensive lesson...the heat from the speedlight is so intense that it will melt and warp the gel IR filters. What I did when I started experimenting was to buy a Stofen Omnibounce, cut off the front of the Omnibounce and cover the whole omnibounce with developed-unexposed film. This cut off the visible light but allowed a modified camera to capture photos in complete darkness. I've photographed people in the dark without them being aware. For a slightly more advance version, I got a piece of ELP filter, cut it and glued the pieces together to form an IR omnibounce. To go completely to the extreme, you could modify the flash with an IR flash bulb. Not sure if these are readily available but know that they exist. Cheers, Matt

Hi Matt,

Thanks for sharing the information. This is really getting very interesting.
Please elaborate more.

Sorry to ask, what is an ELP filter? Can we put the Hoya R72 filter over the speedlight for it to emit IR lights only, by theory it looks possible.

Need to seek all the expert opinions. Thanks for sharing.

[deadpixel]

Originally Posted by Francis247 Hi Matt, Thanks for sharing the information. This is really getting very interesting. Please elaborate more. Sorry to ask, what is an ELP filter? Can we put the Hoya R72 filter over the speedlight for it to emit IR lights only, by theory it looks possible. Need to seek all the expert opinions. Thanks for sharing.

In theory...it can be done.

A better choice would be to use the Cokin P007 or ELP (Edmund Long Pass) filter as a piece of Hoya R72 large enough to cover the Speedlight would be more expensive than the speedlight.

Cheers,
Matt