Strip Boxes

[Finste]

Hi,

Just finished some of Tim Wallace's vids on Kelby Training. He said something about strip boxes which left me a bit baffled. It was something along the lines of using a light through a strip box at a higher power concentrates the light more than at a lower power. I assume here that he means the output is more narrow. My assumption about what he mean't could be wrong though.

Not having a strip box to hand means I can't test it for myself but it is something I've never heard said about soft boxes before.

Is there anyone here who can explain this a bit more?

Regards

 

[Garry Edwards]

Either what he said is wrong or your interpretation of it is wrong, the laws of physics doesn't allow any difference in light quality resulting from difference in power (although of course if the ambient light level is very high and the generated power is very low it can seem to make a difference.

I suppose he may be referring to the use of a honeycomb grid, which requires a higher level of power to get the same terminal flash energy than without it, but which expands the versatility of the strip softbox.

Probably the best person to ask is the one who actually made that statement...

 

[Finste]

He was using using a bare strip box to light the engine in a car. There was no grid on it. Can't remember which shutter speed but I think it was an f-stop of F22. He was inside with very low ambient light levels. So I don't think ambient was a factor here.

 

[Scooter]

This confused me as well Steven. Tim does say on several occasions that he is ramping up the power of the strip box to get a narrower strip of light (which of course would not happen). However, he's repeating a shorthand version of his full explanation which appears at around 5:20 on the segment called "rear brake light" - and that's where you'll find the answer, which, in summary is:-

He wants a clean strip of light with no fall off. He can't use the grid on the strip box as "cars are basically mirrors" and it would show up (he's shooting towards the strip box which is no more than a foot away from the car), so he ramps up the power, so he can stop the lens down to f/22 - which reduces light "bloom" around the image of the soft-box reflected in the car.

At least that's how I interpreted his full explanation - see what you think.

 

[Finste]

This confused me as well Steven. Tim does say on several occasions that he is ramping up the power of the strip box to get a narrower strip of light (which of course would not happen). However, he's repeating a shorthand version of his full explanation which appears at around 5:20 on the segment called "rear brake light" - and that's where you'll find the answer, which, in summary is:-

He wants a clean strip of light with no fall off. He can't use the grid on the strip box as "cars are basically mirrors" and it would show up (he's shooting towards the strip box which is no more than a foot away from the car), so he ramps up the power, so he can stop the lens down to f/22 - which reduces light "bloom" around the image of the soft-box reflected in the car.

At least that's how I interpreted his full explanation - see what you think.

I'll have another look at the video soon but that is an interesting explanation.

 

[Sebastian]

I think he is talking about the effect that he's after that can be achieved by high power flash through softbox AND f/22 aperture on the lens. It's a combination of both, that's how I get it.