Flash Meter ... how to read these?

[hk300]

I saw the other thread about Flash Meters and since i did not want to get that thread too much off the original topic, i made another post.

Most basic Flash Meters only have ISO and Aperture, but no mentioning of Shutter Speed. So, does this mean that these basic meters assume a certain Shuttter Speed? Or. how should i read these?



I have used a more complicated Flash Meter, which also gives Shutter Speed.

[j.lukow]

Alex I share your desire for an answer to this question as in the gear I received was a chinon flash meter.
I haven't experimented with mine yet, but I would think that the meter assumes standard sync speeds for a camera and flash. (Though I thought there was some variation in this area - some are 1/100, some are 1/60 and others . . .??)
Hopefully someone more experienced will help out . . .

Jim

[cooltouch]

It's quite simple. Obviously, the most important thing about shutter speed when using a flash is making sure that the camera is set to flash sync or slower. This is because the shutter curtains are open fully at that setting or slower. Faster speeds and the second curtain follows the first one, making a slit of varying sizes depending on speed, that moves across the film (or sensor) plane. If you fire the flash at speeds great than sync in a camera that uses curtains, the image will be exposed as a slit at high shutter speeds, and just a portion of the frame at slower speeds above sync. This isn't an issue with lens shutter cameras such as Rolleiflexes or Hasselblads, where the shutter opens completely at every speed setting.

A photo flash produces a very fast burst of light -- typically around 1/10,000 of a second. So, shutter speed, as long as it isn't set too low, is immaterial for exposure. Set it too low, and you'll get a double image effect, or a blurred image overlaid against a sharp one. The latter can be an interesting effect, but may not be desirable if unintended. I have often done this -- setting the camera to B for a long exposure, then manually popping the flash and immediately closing the shutter. Doing this with moving subjects in relatively low light can make for some cool photos.

Best,

Michael

[Rob Leslie]

This question is quite simple. The shutter speed has nothing to do with the flash exposure because flash has a very short duration (High shutter speed)
However the shutter speed you set on the camera is most important to the balance of light and the result you get. First any shutter speed you do set has to be within the cameras Flash sync range, then it is up to your skill to pick the right one.
A high shutter speed will in many cases result in an exposure were only the parts of the subject lit by the flash will be correctly exposed, while a slow shutter speed may as already mentioned result in a double image etc or even over exposure of the whole picture.
There isn't a correct or a wrong shutter speed (Within Sync range) it all depends on what you wish to achieve
For a full explanation of this do a search for info on fill flash and slow sync flash. Read through what you find and all should become clear.
It is difficult for anybody to give easy cut and dried answers on this, which is why you should read up on these topics and understanding the basics by going through the examples a good site, or book will give you.
Having control of the shutter speed is just one of the many factors that make flash the most versatile and controllable light source we have.
Many don't fully understand more than the simple idea of a sync speed so miss out on what it is supposed to do.

[martinsmith99]

Ambient exposure is controled by aperture, shutter speed & ISO.

Flash exposure is controled by flash power output, aperture & ISO. NOT shutter speed as the flash fires in a fraction of the time that the shutter is open. The meter you have is fine for studio work.

For creative purposes, balancing the flash and ambient can be achieved by adjusting the shutter speed. This is where your meter falls short.

I suggest a visit to www.strobist.com as there are examples there (although the guy doesn't use a light meter).

[Rob Leslie]

[martinsmith99]

Yes that's why I said that his meter will be fine for studio work where ambient should pose an issue.

I use the Sekonic 358 which as you may know measures ambient and flash(es) at the same time. I've done the chimping thing and it's fine if you have time, but working with models or doing portraits it looks a bit amature.

I had only been shooting with a real camera before I read the Strobist stuff. I learned everything from scratch from there. It is a bit daunting and there are easier ways, but it really gets you jump-started into off-camera flash. And it always tickles me when people think that this is something new. It's actually back-to-basics, which is probably the way most of the old school learned from day 1.

[Rob Leslie]

It seems to me that much of the art/craft of using flash has died except for a minority. I blame it on built in units (Which are just a waste of time and space) and dedicated ones.
Who even knows the inverse square law now and most think a guide number is something to do with public transport!
I do (Just) go back as far as flash bulbs and took many photos with them.

[martinsmith99]

I think it's just the laziness of human nature.

Why bother to workout flash power, aperture, shutter speed, ISO and manually focus, when you can just the whole lot on auto and just press the button. It rarely gives terrible results, but never gives great results.

I don't think te manual approach is about to vanish anytime soon, but already it does seem like it's the minority that are still using the correct tecniques.