Off Camera Manual Flash

How do I know what settings to use if not trial and error?!

Thanks in advance!!!

You can use a light meter. Still "trial" but cuts down on the "error".

Thankyou!!

Guide Number is another way.

If the Guide Number for some power and zoom situation is say GN 100, that means exposure is:

10 feet at f/10
5 feet at f/20
20 feet at f/5,
etc.

See Understanding Guide Numbers, including GN Calculator

I was about to post what WayneF said. Keep in mind, it's a suggestion and not an absolute rule.

I think I follow, I think haha!

Good morning everyone,

Probs not the best idea to do maths before work but neverming lol!

My flash is a Yongnuo YN560 iv and it's GN is 58

So using the Formula General Number / Distance in feet = F-Stop

GN/D=F
58/10=f/5.8
58/5= f/11.6
58/20= f/2.9

Please tell me this is right hahahaha

Then there is of course the power output you select. On the YN560 iv that is anything from full to 1/128th which I would think has some sort of impact?

Yes 1/1 to 1/128

Jon Christie said:

Good morning everyone,

Probs not the best idea to do maths before work but neverming lol!

My flash is a Yongnuo YN560 iv and it's GN is 58

So using the Formula General Number / Distance in feet = F-Stop

GN/D=F
58/10=f/5.8
58/5= f/11.6
58/20= f/2.9

Please tell me this is right hahahaha

Click to expand...

That is the right idea, except that YN560 GN 58 (meters) is for 105mm zoom. It has many guide numbers (that is the largest one), and there is a Guide Number chart in its manual, for example 24mm zoom GN is more like GN 28 (meters), ISO 100.

It is a "guide", but should be a pretty close starting point.

Thankyou for the help everyone

Forum rules are very clear... If you ask a question, and get an answer, you have to take and post a picture that demonstrates your question and answer.

Righto, I'll get my little ones to pose haha! I'll just have to get them to stay in one place long enough!!

Jon Christie said:

How do I know what settings to use if not trial and error?!

Thanks in advance!!!

Click to expand...

what are you shooting? at home studio portraiture? people/still life? are you using softboxes or umbrellas?

settings are VERY simple. shutter to Xsync. since you dont list your camera, just use 1/160 or 1/200. aperture to f/4-8. I personally shoot pretty open. stopping down gets ridiculously sharp and shows all pores and that is NOT aesthetically pleasing for women. set those parameters and a low iso of 100-400. whatever you want. it doesnt really matter. then setup your flashes in the softbox/umbrella and next to your subject. shoot a test shot at 1/8 power and look at the screen. overexposed? bring the power down. not enough light? try 1/4. simple as that. keep camera settings the same and power your flash up and down as you need. if you move your subject to different distances from the flash/softbox/umbrella setup then youll have to adjust as necessary.

personally when I shoot wedding formals, I run the flashes at 1/32- 1/16 and move the stands according to how many people are in the picture. if there are many, I have to spread the stands further apart, if not then I make the distance narrower. I usually dont touch the power output of the flashes. I will shoot and look at the lcd and if its over or under, I just adjust the settings in the camera. but im very proficient with flash and you should learn the proper way first. just like a race car driver knows to drive with one foot on the accelerator and one on the brakes at the same time. its from experience.

knowing calculations with GN and such is good to know but its not realistic in the real world. its good to know and nice on paper, but in real life that doesnt work well. if you have a light meter, u can certainly use that. otherwise its very quick to adjust the camera and set it, then adjust flash power output as you go along. usually the subject doesnt move and you can move in and out for proper composition. if you plan on advancing with flash and you dont have radio triggers, consider one of yongnuo which have a TX unit which sits on the camera and allows you to remotely adjust power from the camera and not have to move around to lower or increase output.

FredKingston said:

Forum rules are very clear... If you ask a question, and get an answer, you have to take and post a picture that demonstrates your question and answer.

Click to expand...

This is before I asked

Unfortunately little Leah is away this weekend so I'll bribe one of the boys to pose for the next one haha!!

Jon Christie said:

Righto, I'll get my little ones to pose haha! I'll just have to get them to stay in one place long enough!!

Click to expand...

Flash freezes motion...