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02-01-2020, 06:51 PM - 6 Likes   #1
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I should not have done that....

I haven't noticed a threat of this ilk around the forum, so if I have missed it please redirect me.

I guess I could have named it "forgive me for I have sinned..." but that may give the wrong idea, but I feel I should relate this tale of how I messed up primarily to educate but also to give you a laugh.

I've been working on desktop macro photography for a while, and always have a problem getting enough light on the subject. I've tried various diy options (I can never justify a proper lighting setup both in terms of space and cost} so when clearing out the garage the other day I came across something that made me think "I wonder if that would work..."

The something in question was a security floodlight that would be attached to the outside of the house. I bought two several years and a couple of houses ago but never got round to wiring them up. They have been moved from place to place under the banner of "that'll come in useful, I'll keep hold of it", but this time I had time on my hands and a will to achieve, so I set about wiring one of them up with a mains plug with the intent of using it as a general worklight.

Anyhow, after checking that yes I was indeed permitted to wire it up myself in this state, I attached a metre or so of three core cable, added a plug on the other end of the cable, and tentatively plugged it into a mains socket in the garage. I waited specifically for a cool day, I didn't want to blow the house RCD when it was hot as the memsahib would not be impressed if the air conditioning went off. Anyway, plugged it in, switched it on, as as the bible says "Let there be light", and there was!

The next step was to see if I could use it for macro work. I took the newly tested floodlight into the house, put it on the table next to the gadget I use to hold the subject of my attentions, and plugged it in. Well the result was fantastic, all of a sudden I could see the difference in light levels on the subject so I set about focusing and adjusting. After about a minute however I looked up from the viewfinder to see a wisp of black smoke. Bit of a panic there, so I immediately pulled the flood light plug out of the mains and went looking for the source of the smoke.

A rapid investigation did not find any electrical issue, but did find a rubber hood over the lens was extremely warm to the touch and slightly sticky.

So children, the lesson for today was - a 2 kw quartz halogen flood light puts out a lot of heat very quickly...........

Anyone else care to share some gaffs while in pursuit of an image?

02-01-2020, 07:26 PM - 5 Likes   #2
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I recently burnt my finger while shooting a grilled cheese sammich...
02-01-2020, 07:34 PM - 2 Likes   #3
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Many have learned that photons can be exuberant little buggers when allowed to gang up on unsuspecting black things under the right (=wrong) circumstances.

If I am careful, I can point a binoculars at the sun (WITHOUT LOOKING THROUGH IT!!!!!!!!!!!!!!!!!!!) and project a very nice sharp image of the sun some feet from the eyepeice on a sheet of paper.

But if I am not careful (it happens!) and the binoculars sits off-axis or the stupid planet keeps spinning, then the sun's beam of light moves away from the clear glass path of the optical axis and on to the internal black tidbits inside the binoculars. The binoculars fill with smoke.

---

There was a documentary on Harold Edgerton (a pioneer in electronic flash and high-speed photography). One of the demos has a sheet of paper held in front of one of Edgerton's brighter flashes which when fired sets fire to the paper!
02-01-2020, 10:46 PM - 3 Likes   #4
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In the last few days an Australian Army helicopter started a massive bushfire using its landing lights. So don't feel too bad.
How a landing light from a Defence MRH-90 Taipan helicopter sparked the Orroral Valley fire | The Canberra Times | Canberra, ACT

02-02-2020, 12:03 AM - 3 Likes   #5
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thinking_BeardAs soon as I read the line General work-light I knew something was about to either get melted, or catch fire entirely.


QuoteOriginally posted by officiousbystander Quote
In the last few days an Australian Army helicopter started a massive bushfire using its landing lights.
A rather illuminating faux pas.
02-02-2020, 02:27 AM - 3 Likes   #6
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Lensball - ouch!

I got a lensball to see what it could do. Living in the Algarve (Sourthern Portugal) the sun is very bright and very, very hot.

Hold it up in one hand with camera in t'other and OUCH!! Lesson learned!!
02-02-2020, 08:36 AM - 1 Like   #7
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QuoteOriginally posted by officiousbystander Quote
In the last few days an Australian Army helicopter started a massive bushfire using its landing lights. So don't feel too bad.
How a landing light from a Defence MRH-90 Taipan helicopter sparked the Orroral Valley fire | The Canberra Times | Canberra, ACT
Yikes. Too many fires already down there, that crew must feel terrible.
02-02-2020, 12:12 PM - 1 Like   #8
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If you're stopping your aperture way down for good DOF, I understand you might need a lot of light if you don't want to use slow shutter speeds. But 2KW? Security lights are for high illumination of large areas. For desktop macro photography (of small things presumably) could you use 150 watt equivalent LED floodlights? They draw much less than 150 watts, and run much cooler. At some places you can get floodlights with different coverage angles. If I'm not mistaken, a PAR50 flood covers a 50 degree wide cone of light. A PAR25 of the same wattage would concentrate the same amount of light into a 25 degree cone, so more lumens per square inch. Just a few thoughts.

02-02-2020, 01:15 PM   #9
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I second Apet-Sure idea, unless... you experience strange behavior (some channels getting lost) on any flat screen TVs in the house while using LED lights (Wife and/or kids may not appreciate that).
02-02-2020, 06:17 PM   #10
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Original Poster
QuoteOriginally posted by Apet-Sure Quote
If you're stopping your aperture way down for good DOF, I understand you might need a lot of light if you don't want to use slow shutter speeds. But 2KW? Security lights are for high illumination of large areas. For desktop macro photography (of small things presumably) could you use 150 watt equivalent LED floodlights? They draw much less than 150 watts, and run much cooler. At some places you can get floodlights with different coverage angles. If I'm not mistaken, a PAR50 flood covers a 50 degree wide cone of light. A PAR25 of the same wattage would concentrate the same amount of light into a 25 degree cone, so more lumens per square inch. Just a few thoughts.
Cheers for the response, you're correct I am stopping down the aperture and using slow shutter speeds, I guess the desire was to use faster shutter speeds to get over some vibration issues I have been having.

I haven't seen the 150 watt figure mentioned, thanks for that. I'll check the ratings of the lights I currently have and see what I've been working with.

Thanks to everyone for the responses, while I admit the 2 kW is a bit overkill like all "good" ideas it seemed perfectly reasonable at the time......
02-02-2020, 10:04 PM - 1 Like   #11
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My SMC Pentax Photo Lupe 5.5x actually has a warning label on it.

"To prevent FIRE , never leave the magnifier in a location where it is exposed to direct Sunlight"

Words to live by.
6 Days Ago   #12
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LEDs aren't allowed created equally, the spectrum isn't full. Look up cri in respect to LEDs.

Here's a biased view but it gets the point across:

"Daylight" does not mean full spectrum - Lumicrest High CRI LED Lighting
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