Product photography - a lit torch

Frogroast · 01-04-2009, 07:36 PM

I have a bit of a challenge on my plate and perhaps someone here can give me some suggestions as to how to improve on the results.

A local manufacturer wants me to shoot torch flames to show the QA people on the manufacturing floor what to look for in a good flame (prints at each station for them to use as reference). I did a couple of quick test shots with my K10D, to determine what kind of composition the client wants.

The shot below is representative of what they're looking for. FYI - the reason why the stem of the torch is lit is because I used a flashlight to focus. It looked so much better than with just the blue flame, that I left the flashlight on for this shot.

Here's my challenge: They want to be able to see the detail in the flame core - the twist of the flame caused by the thingamabob inside that causes the flame to get turned and focused. That means forget ultra high ISO and slow shutter. I tried a combination of both, but couldn't get it quite there. The pic above is at ISO 100 and 1/2 second exposure. Even at ISO 100 you can still see grain.

I also have to worry about not getting too close to the torch, I can't run the torch for more than a couple of minutes at a time (per the company's instructions), and I have to shoot outside due to the propane fuel burning and CO2, which means at this point I have to shoot and freeze!

Anyone ever shoot this before? Blue/purple light isn't very bright, so what are my options here?

Just had a thought - would a polarizer filter help here?

BPT · 01-04-2009, 07:52 PM

Would using a flash and a slow shutter work? That is generally what I do for fire, the flash brings out the detail and the slow shutter brings in the flame

navcom · 01-04-2009, 08:01 PM

I know exactly what you are going through! I worked on a project for a company several years back and needed to show the floor workers different port patterns for various pilot light assemblies. It was natural gas and LP assemblies but much the same.

If I remember, it was really a trial-and-error thing with backlighting. With no backlighting, the flame was always too bright and inner detail disappeared. Too much backlighting and the flame itself disappeard. I'm working on memory here which isn't too good these days.

I don't remember aperture or exposure settings.

I also did some touch-up with Photoshop to get the final result the way I needed it.