Flash HELP

[Starskream666]

Just got a 6d its my first full frame so now my 50mm is more practical for portraits. I'm starting club photography work and instead of using my fisheye I want to start using my 50mm.
I always hate using my 50mm in dark scenes with the flash because I get this problem.

Either the whole background is also lit up, or practically nothing is lit up. It's really frustrating. Here is an example.

flash was on about 1/60 power maybe. and the zoom was on 80mm (i tried different zooms, all had the same effect, nothing really changed)

I tried lots of different variations. Each resulting in either a lit background or nothing hardly lit.

I want to get the subject lit nicely but the background not to be exposed so much.. but ambient light from say lasers etc left in.

Ignore my expression haha I was very tired

 

[Braineack]

I'm assuming this flash doesn't have TTL?

 

[tirediron]

How to get perfect flash exposures every time.

That aside, there's a lot more to this than simply setting an aperture and shooting. You need to spend some time reading up on how flash exposure works, learning how to separate the flash exposure from the ambient exposure, as well as techniques such as rear-curtain sync.

 

[KmH]

When you change the zoom setting the shape of the beam of light the flash unit produces changes.
At the shorter focal length zoom settings on the flash unit the beam is wider because the lens FoV (field of view) is wider.
At the longer focal length zoom settings the beam is somewhat narrower because the FoV of the lens is narrower.

If the flash was to bright at 1/60 use a lower power setting.

The exposure of ambient light is controlled with the camera ISO and shutter speed settings.
The flash exposure is controlled with the lens aperture and the flash unit power setting.

Having the flash unit on the camera aims the light at that part of the FoV containing both your subject and the background.
If you get the flash unit off the camera you can light your subject but have that light fall on background that is not in the FoV.
An additional benefit is that your subjects facial features will make some shadows which give a person's face more character than a straight on flash of light that does not produce those shadows.

For event/club photography, one way to do that is to get the flash unit off the camera (OCF), and hold the flash unit with your left hand and the camera with your right hand.

 

[Designer]

Just got a 6d its my first full frame so now my 50mm is more practical for portraits.

I don't get this. Usually in portraiture the photographer will minimize distortion by using a LONGER focal length lens, not shorter. When you put the 50 on a full frame, it has the effect of appearing shorter, not longer.

When I used a full frame we considered the STARTING point to be 105mm, up to about 135mm to be optimum, and even longer if there was room enough.

 

[Designer]

I'm assuming this flash doesn't have TTL?

Or he was in manual mode. (?)

 

[tirediron]

Just got a 6d its my first full frame so now my 50mm is more practical for portraits.

I don't get this. Usually in portraiture the photographer will minimize distortion by using a LONGER focal length lens, not shorter. When you put the 50 on a full frame, it has the effect of appearing shorter, not longer.

When I used a full frame we considered the STARTING point to be 105mm, up to about 135mm to be optimum, and even longer if there was room enough.

Since the OP mentions club photography, I think it's safe to assume that he's not looking for HCB-type classic formal portraits, and therefore, the lens choices are a bit more varied.

 

[Designer]

Of course, if his room is 12 feet wide, and there is a 6-foot wide moat down the middle, then sure, the 50 is "more practical" now.

 

[Starskream666]

I'm assuming this flash doesn't have TTL?

It's a yungnuo 560 ii sorry and no i dont believe it does

 

[Starskream666]

Just got a 6d its my first full frame so now my 50mm is more practical for portraits.

I don't get this. Usually in portraiture the photographer will minimize distortion by using a LONGER focal length lens, not shorter. When you put the 50 on a full frame, it has the effect of appearing shorter, not longer.

When I used a full frame we considered the STARTING point to be 105mm, up to about 135mm to be optimum, and even longer if there was room enough.

What I meant to say is more practical for nightclub portraits. Rather than trying to use it on a crop which is about 80mm.
This is not a thread about the best suited focal length for portraiture and it definitely isn't to show of my technique in shooting my own image in my bedroom

 

[Braineack]

I want to get the subject lit nicely but the background not to be exposed so much.. but ambient light from say lasers etc left in.

youll want to set your camera so it exposes the background pretty much how you want it without flash-- so a low ISO (200-400) and faster shutter (1/80-1/200).

then you add the flash to expose for the subject. The aperture will control the brightness of the flash (beyond the power level), so you can use smaller apertures to get things in focus (f/5.6-8).

If you need more ambient, you can increase the ISO or slow the shutter. The flash will keep subjects in focus, but you can start getting double exposures if your long shutter also exposes your subject and then so does the flash.

Eventually you'll start wanting to use like iso 100-200, 1/4-1/20sec on rear sync flash so you can capture light trails, and then the flash will expose/freeze your subjects.

I quite often will jack the ISO all the way up to 6400 even with flash because I want both the bg and subjects bright.

 

[photoguy99]

This doesn't help you any, but this wasn't a good flash choice for you. If you can't afford TTL, at least get a thyristor flash (that essentially does its own metering) and use that. In a club where distance to subject varies constantly this thing is going to be a constant nightmare. You're paying for radio triggering which you're not using. Monet better spend on a thyristor or TTL.

My best guess at a usage model would be to:

- set up for aperture priority, dial in 2-3 stops of underexposure
- set the flash up for a good "average distance to subject" at a good "average middling aperature", say, 10 feet and f/5.6, by adjusting the power level
- if your subject seems closer than your average middling distance, stop down
- if your subject seems further away, open up

The first will manage the shutter speed to give you a dim but present background, like a club ought to be. The second will give you a good exposure at the distance and aperture you've selected -- do some trial and error here to figure out what a good power level is.

The next two will allow you to compensate in both directions. The flash will be too powerful, for subjects that are closer, so stop down. The shutter speed will adjust automatically to expose the background right. And the reverse. Practice some to get a handle on how much to stop down or open up.

Shoot RAW so you can fix the inevitable -- but hopefully moderate -- exposure errors in post.

 

[Starskream666]

Thanks for some great replies.

Photoguy would you suggest having the camera metering on evaluative metering then? I usually use spot metering a lot

 

[photoguy99]

Uh, sure. Evaluative metering! Why not! Honestly it doesn't even matter much. You just want it to get somewhere in the ballpark for the background -- in the face of a changing aperture. You're using the aperture to control your relative flash power, essentially, and you want the camera to do something sensible with the shutter speed to get something for a background. Otherwise I'd say just shoot manual.

Which you could do. The workload gets higher, though, since you have to adjust shutter speed and aperture.

 

[Braineack]

I would shoot manual.