Wednesday, November 11, 2009

Hey, Your Flash is Hawt

No, not as in the vapid, Paris Hilton sense. But rather the laws-of-thermodynamics sense.

Made-for-photography gels are meant to be used near theatrical light sources. So they can handle the heat. But even still, the front lens of your flash can get very hot with repeated cycling -- especially at higher power settings.

Don't believe me? Try this little trick:

Hold a piece of printer paper right next to the front of your flash and set off just one, full-power pop. Now smell the paper. That would be a burning smell. From just one pop.


Be Cool

When you gel, leave a little space between the flash and the gel for the super-hot air to escape. This helps with cooling.

And if you melt a gel, there is hope. I had not heard of either of two cool fixes before reading this thread, but apparently all is not lost.

And if anyone else has other methods of de-gelling your front flash lens, please share in the comments …
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FULL DISCLOSURE: The flash photo up top was not actually discolored by a gel. It was fried by being repeated triggered at 1/2 power from another shooter's nearby PocketWizard.

But it really came in handy as an illustration for a fun little April Fool's post we did back in 2008…


-30-


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31 Comments:

Blogger Phat Baby Photographer said...

I usually just lick my gel and stick it on my flash because it's fast, but now I can say it helps keep it cool.

November 11, 2009 12:35 AM  
OpenID pixeldarkroom said...

Good to know about this. I use a gel holder myself (home made, details here) and was thinking of getting extra gels to cut myself some new gels and maybe use straight velcro on them. It's good that I know about this now.

November 11, 2009 12:38 AM  
OpenID pixeldarkroom said...

Man, I only did that once because I did not have a velcro strap on that particular flash. I couldn't say it was my favourite solution.

November 11, 2009 1:01 AM  
Blogger Anshu said...

Both Rosco and Lee make High Temperature (HT) versions of their popular gels. Check those out too. Also note that if your using a free gel book, Rosco and Gam and deep dyed polyester and Lee and Appolo are surface coated. Aka the Rosco and Gam and better at taking the heat.

November 11, 2009 1:11 AM  
Blogger Nick Davis said...

Great, now my wife's gonna walk in and find me licking my gels to see if they stick to my flash...

Cycle 61 Photography

November 11, 2009 1:20 AM  
Blogger DEFINITIVE IMAGES said...

Thanks for all the tips senor strobist, I appreciate your work with flashes it has led me to acquire my own arsenal of speedlights. Keep shootin'!

November 11, 2009 1:37 AM  
Blogger Brittney said...

I've never melted a gel on mine, but one of my SB600s does have a little black dot on the front that I figure is a scorch mark.

November 11, 2009 3:34 AM  
Blogger Per said...

I believe that smell is ozone, not burnt paper. It is not from the heat, but from exposing air to UV photons. (The paper just helps concentrate the photons. You could replace it with something non-flammable, such as a mirror, and still get the same smell.)

November 11, 2009 6:19 AM  
Blogger Richard said...

I've used depron (foam) to dim the output of the flash for macro photography and that melted after a couple of shots at 1/64th...

Richard

---
www.urban-exploring.com

November 11, 2009 6:44 AM  
Blogger Kate@MKDPhotography said...

Man wish you had been at our engagement session last week you could have warned us about the red gel that is now melted on the front of our SB-900...I bet Nikon sees some crazy stuff to repair!

November 11, 2009 7:57 AM  
Blogger Don Sweener said...

How about drilling some small venting holes in the face of the flash?

November 11, 2009 10:19 AM  
Blogger David said...

Per-

No so sure -- if you do it with a V283 at full power, the paper actually smokes.

November 11, 2009 10:27 AM  
Blogger supergimp said...

Interesting. I was wondering about this as I was sitting in McNally's Kelby Seminar last week in LA. He tapes his gels on all sides to the front of his SB's to prevent light leakage. In fact, at one point, he was able to demonstrate why when the gel wasn't sealed to the front and the light leak showed in the image.

I guess when you travel with a crate of 300 SB-900's you can afford the risk. My guess is McNally doesn't even bother to change batteries - he just tosses the strobe and cracks open a new one!

Amazing seminar BTW!

November 11, 2009 10:36 AM  
Blogger TheShape said...

Its funny that you posted this now. I put one of my red gels (strobist pack too) right in front of the flash a few days ago, just one pop on full power put a small melted crease in the middle of the gel. Sucks.

November 11, 2009 1:13 PM  
Blogger Joshua Chang said...

You can also pop balloons! I did it once on accident during an event and had fun doing it a later as I didn't think I actually did it!

November 11, 2009 1:22 PM  
Blogger Michael said...

Oh sure - where was this post BEFORE I stuck orange plastic from a Halloween candy bag over my SB-25s to shoot my pumpkins?

:P

(The toothpaste trick works, BTW)

November 11, 2009 1:37 PM  
Blogger Mike said...

I've put a 580ex on full power and pressed it against a friend's forearm and it burnt the hairs and his skin a little. No marks or anything, but it does get hot.

November 11, 2009 2:48 PM  
Blogger Flashing Dutchman said...

This comment has been removed by the author.

November 11, 2009 3:04 PM  
Blogger Flashing Dutchman said...

Can the use of the Lumiquest FXtra speed the melting procces up? is it better to velcro the gels with an air gap between?

Does anyone have experience using the Lumiquest FXtra and the melting problem?

November 11, 2009 3:04 PM  
Blogger David said...

I slide in Rosco Gels in the slot of my Vivitar 285Hv's is that safe ?

Other than than the fact that they fall out at times :-)

November 11, 2009 3:06 PM  
Blogger Chris Biele said...

I melted a red Rosco gel in one of my Viv 285's. It's still useable (the gel) and the flash wasn't harmed. Made me realize though.

November 11, 2009 6:53 PM  
Blogger wilko said...

I tell you what...
About a year ago I was sitting on the couch with a Canon 580 flash. The batteries were almost dead so I thought, lets do a series of flashes full power to empty the batteries. To avoid hurting my eyes I put the strobehead on my jeans........
Flash, AUCHHHH, smoke............
I ended up with a pair of new jeans with a white streak on it, the indigo colour burnt of my pants.
BTW, yes, I also melted some gels...

November 11, 2009 7:00 PM  
Blogger Keith said...

I have not melted a filter to any of my flashes (yet!), but I did have a "don't try this at home" moment recently. I was showing off my shiny new 430ex II to a coworker. As this is kind of a no-no at my place of employment, I fired the flash closer-than-I-should-have to a black drape. I popped the flash and immediately saw a puff of black smoke and smelled a burning smell. The drape had a singe mark shaped like the business end of the flash. Fortunately, the flash was unharmed...

November 11, 2009 7:21 PM  
Blogger Ken Norton - Image 66 Media said...

Flashes put out a ton of IR light. It's the IR that is generating most of the heat melting the gels.

For a number of years I used high-heat stage-light gels on my V285 flashes. They do start to brown very quickly even though they are designed for hundreds of hours of 500-1000 watt use.

The primary difference between a stage light and a flash is that nearly all stage lights pass the IR radiation THROUGH the mirror towards the back of the fixture and very little IR is actually sent through the front towards the stage.

An SB800 is a bright flash--but not really any brighter than most higher-end flashes. The big difference is that the SB800 is achieving that brightness with a much smaller tube/reflector than most units.

November 12, 2009 4:03 PM  
Blogger Brad Curfman said...

This happened to me after one or two pops at full power. I I had just gotten my first sample Rosco gel pack and put a purple gel between the diffuser and flash head. Voilà! Purple people flasher!

I removed the remnants of the wrinkled gel and decided that it should be just as easy to melt off the residue as it was to melt it on. I fired off a half dozen more bursts at full power and used a stiff dust brush to wipe off the purple residue.

No stain was left on the flash.

November 13, 2009 10:41 PM  
Blogger nvonstaden said...

you also have to watch out for that little red button on the back...hold it in the you get a strob ....if its in a tight pocket of your camera bag it could really cause trouble...that melted the cover on mine....

November 14, 2009 12:53 AM  
Blogger Ian said...

I took a couple of shots outdoors in cool conditions with my SB900 at high power with a full CTO in its little custom holder. When I went to take the gel out again there was a ribbed pattern over its centre where the heat had distorted it. I'm guessing that's why the Nikon holder is designed to keep the gel off the face of the flash's lens.

Thanks for all of your inspiration David, a whole new workd has opened up to me.

November 17, 2009 7:57 AM  
Blogger NtwkGestapo said...

I have no comments to make on this specific posting, BUT, I've got to say I REALLY enjoyed the 1 Apr 2008 post! Having come from an electrical engineering background and having worked with high voltages (anything from 1 kilovolt to 180 kilovolts. Anything under the 1KV range is dangerous voltage but not HIGH voltage, at least to me!). I just about fell out of my chair reading the "super secret method" of getting additional watt seconds from your flash! ROFL!!! Good 'Un!

November 18, 2009 4:07 PM  
Blogger eugene said...

I'm wondering the same thing as the Flashing Dutchman - will the Lumiquest FXtra work OK?

November 22, 2009 10:01 AM  
Blogger Ken Warren said...

Things you definitely shouldn't do with an on camera flash: I used to use a Metz 60-series flash (needed the range) back in the old days, when I used film rather than digital. One day I wasn't thinking, and when I reloaded I left the flash turned on and laid it down on my leg. When I closed up the camera and it triggered the autowinder, it also triggered the flash. Which burned a 1/4 inch wide blister into my thigh, through my black trousers (which through photobleaching now had a 1/4 inch gray line on the thigh). I still have a scar.

That flash would also kill an insect dead in mid-air, or sunburn your ear if you were bouncing off the wall bahind you. I'm glad I don't use it any more...

November 22, 2009 2:05 PM  
Blogger David said...

Have not had any reports of LumiQuest FXtra causing any overheating, and they have been out there for months now.

But still, I would personally choose to mount it in a way that allowed air to escape along the sides. Especially if/when using high power on your pops.

Just good workflow, IMO.

-DH

November 23, 2009 2:47 PM  

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