Off Camera Softbox Speedlight and underexposed pictures

werds wrote in post #17992868
OK, although probably not a question for this thread - it still feels as if it pertains to this thread. I assume a handheld lightmeter would help? I mean from what I understand, I would hold the meter where the subject would be and it reads out the several combinations of required shutter/ f.stop/iso to get a proper exposure right?

How does that work in terms of it assuming the amount of light that will be provided by the lighting setup?

You need a lightmeter designed for flash.
And as I said earlier - shutter speed shouldn't be considered a variable when shooting flash. You should stick to the x sync speed, there are exceptions to this, but it'll not help you to learn about them before you've got your head round the necessary knowledge.

Awesome, thanks!

Phil V wrote in post #17992921
You should stick to the x sync speed, there are exceptions to this, but it'll not help you to learn about them before you've got your head round the necessary knowledge.

Ok so to get it straight my D750 has a max sync of 1/200 and my D7200 has a max sync of 1/250. So do not go above those and use multiples below that correct? At least until I grasp the whole setup better.

Bassat wrote in post #17992857
Which is part of the reason I always deploy my diffuser panel when using umbrellas.

lest we cause others to completely misunderstand the purpose of that panel, it's better to refer to it by Canon's name "wide panel"...which is what it does, it does not 'diffuse'

Phil V wrote in post #17992916
But he's using a 47" Octa with the flash mounted at the back

yeah, and so he needs to position his flash at 47" from the Octa, with the flash head set at 24mm coverage angle, or not make full use of its size

werds wrote in post #17992868
OK, although probably not a question for this thread - it still feels as if it pertains to this thread. I assume a handheld lightmeter would help? I mean from what I understand, I would hold the meter where the subject would be and it reads out the several combinations of required shutter/ f.stop/iso to get a proper exposure right?

How does that work in terms of it assuming the amount of light that will be provided by the lighting setup?

Wanna ask your question, phrased a bit differently?

You set a lightmeter at flash mode ('corded' or 'cordless'), hold its hemishere at the subject and point it at the lens, fire the flash and look at the reading (for the preselected ISO and f/stop).

Shutter speed does not matter for flash exposure (as long as you do not exceed X-sync speed), but shutter speed DOES affect any recording of ambient light...pick a slow shutter speed and flash illumination is unchanged but dim room light records -- and if your subject moves it is recorded as subject motion BLUR, in addition to a sharp exposure from the very brief flash illumination.

Well you nailed it! I have no idea how a light meter works so I was assuming that I either had to punch in values for the lighting or figure out how to hold the light meter in the spot I need while triggering the strobes to get the incident reading. I just didn't understand how it worked since I don't have my hand on a light meter nor ever used one before

So I think for now I will hold off on that purchase although I see how it might be helpful to speed up the process in the future... but I agree I need to grasp basics first!

Wilt wrote in post #17993032
yeah, and so he needs to position his flash at 47" from the Octa, with the flash head set at 24mm coverage angle, or not make full use of its size

But his flash is attached to an s type bracket mounted on the rear of the Octa. He hasn't a method for attaching it facing into the 'umbrella' 47" away.

Phil V wrote in post #17993256
But his flash is attached to an s type bracket mounted on the rear of the Octa. He hasn't a method for attaching it facing into the 'umbrella' 47" away.

And so he does not get to make full use of his 47" modifier.

photovision target card

This will allow you to set the exposure pretty darn close, and also the WB (sometimes, strobes, and their modifiers will have color temp other than the standard 5500K) You can buy it from adorama/b&h/amazon or ebay.

There are, of course, many ways to skin a cat, but the above comes with an instructional video, and lays it out step by step, and should be useful in getting you where you want to go, without spending a ton of money.

I've never had a lightmeter in my life, unless you count the one in the camera. Yes, I chimp, but it is pretty fast, and I've got to the point I know where to start.. nothing beats practice practice practice.

Wilt wrote in post #17993322
And so he does not get to make full use of his 47" modifier.

Which is what I said originally

Phil V wrote in post #17994055
Which is what I said originally

Via your replies in your posts (20, 23, 26)you seem to think I was disagreeing with what you had said in post via my Post 13, and that you have been 'countering' my posts.
In post 13, I was agreeing and AMPLIFYING to the OP what you said earlier, in providing information about the coverage angle and placement necessary to fill any umbrella, "distance = diameter"

OTOH, although I did not disagree with your statement in post 6 (although incorrect), "Again the inverse square law kicks in for size - the further away the light the smaller it's apparent size."
The fact is that Inverse Square law does NOT APPLY for a 'large source' (like an umbrella) when it is used at less than 3x its largest dimension, the falloff of light intensity for large sources at short distances is close to 'Inverse linear'.