Metering

Livin The Dream

Livin The Dream

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Kris
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Are those that are using cheap ebay type radio triggers using flash meters to obtain correct exposure quickly or relying on your experience?

I ask as i'm planning to buy the PW mini & TT system after i've got an extra flash and stands etc but for the time being to get me going i've gone for the cactus V4 kit. I'm thinking to begin with a meter will help speeden the whole thing up for me,

Cheers
 
If I have time I'll always start by using the meter... then adjust from there if needed.
 
If you only have one light, I would say don't bother with a meter at all. It's easier, and more accurate, to go off the LCD/blinkies/histogram. You can even do it with two lights without too much trouble.

But when you get three or four, as you might when trying to blow a white background just right, it get's very complicated without a meter.

Meter allows you to set lighting ratios easily and accurately but when you've done that I find the final overall exposure setting is quite often not exactly what the meter suggests. I make the final adjustment with f/number or ISO, not by adjusting the lights further, so the ratios stay fixed.
 
Just a related question. Assuming most studio lights have a constant setting as well as flash, can metering be done by turning on the lights and metering the subject using the camera metering? I appreciate that might not be as accurate as a dedicated flash meter but will it work in the absense of a meter and will it be quicker than shoot/check/shoot/check etc?

Just a though.
 
AndyB said:
Just a related question. Assuming most studio lights have a constant setting as well as flash, can metering be done by turning on the lights and metering the subject using the camera metering? I appreciate that might not be as accurate as a dedicated flash meter but will it work in the absense of a meter and will it be quicker than shoot/check/shoot/check etc?

Just a though.
Click to expand...
That will work if using only the modelling lamps, it won't of course measure the flash
 
Nope - flash is much more powerful than the modelling lights - so they won't give you an accurate exposure indication.
 
Yes I realise that. What I am suggesting is that the studio strobes (at least the ones I have used) have a mode where the full light is on constantly - not the modeling light. So if one was to meter with the full light on and then switch to flash mode the exposure should be good. That's my theroy anyway but if 'always on' isn't a mode comon to all studio lights it isn't going to work.
 
AndyB said:
Yes I realise that. What I am suggesting is that the studio strobes (at least the ones I have used) have a mode where the full light is on constantly - not the modeling light. So if one was to meter with the full light on and then switch to flash mode the exposure should be good. That's my theroy anyway but if 'always on' isn't a mode comon to all studio lights it isn't going to work.
Click to expand...

Normally if the light is constantly on this is the modelling light, this can be adjusted up or down for you to visualise the light/shadows etc.

The full bulb only flashes for a few whatevers of a second.

It is easier to measure with a flash meter otherwise it is guess work or from previous knowlege.

:thumbs:
 
I don't know what you mean by 'full light' If you mean the light that can be set to be on constantly, that's the modelling lamp, and it's only function is to indicate the direction and strength of shadows.
How well it carries out even that limited function depends on the power of the modelling lamp and the amount of ambient light in the room. The modelling lamp isn't a substitute for a flash meter.
 
I'll need to have a closer look at the lights in the studio at the weekend. From what you are saying here there isn't a way of switching the lights so that the main light stays on (at the output the flash would be) which is what I was saying. I'm not talking about modelling lights - I do realise that wouldn't work :)
 
AndyB said:
I'll need to have a closer look at the lights in the studio at the weekend. From what you are saying here there isn't a way of switching the lights so that the main light stays on (at the output the flash would be) which is what I was saying. I'm not talking about modelling lights - I do realise that wouldn't work :)
Click to expand...


I think i know what you are trying to say..

No the main flash bulb will not stay on.
It just flashes as the name suggests...

The only way to do it with in camera is to set it manually to 1/125 and F8 and adjust the flash to suit. But it is much quicker with a light meter.

Ps
Studio lights only have 2 lights:
1) Modelling light
2) Main flash bulb



Mark
 
AndyB said:
From what you are saying here there isn't a way of switching the lights so that the main light stays on (at the output the flash would be)
Click to expand...

No. You can't do that. The power required would melt your electricity meter!


Steve.
 
lol - I had thought it might be a little hot. OK thats answered my question anyway
 
AndyB said:
lol - I had thought it might be a little hot. OK thats answered my question anyway
Click to expand...

When you fire a flash tube you send it a trigger pulse which ionises the xenon gas inside.

This causes it to conduct and effectively short cirtcuits the capacitor and discharges it in a very short time.

The flash lasts for less than 1/1000 of a second so to run continuously, it would need to provide more than 1000 times its power every second. That would be a seriously large power supply and would probably destroy the tube in a few seconds.


Steve.
 
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