# Confusion with lighting and flash sync speed.  Help.



## jwbryson1 (Oct 30, 2011)

I set up my new black backdrop, put my camera in manual mode and adjusted the setting to f/4.5 and 1/640 shutter speed which totally eliminated all signs of the backdrop and all ambient light which was my goal.  I put my subject in front of the backdrop, took my SB-700 off camera and angled it to bounce light off the ceiling.  When I took the shot, however, the shutter speed was 1/200 which is my D90's flash sync speed, and of course the lighting is a bit hard, the backdrop appears and there are shadows.  Not what I wanted or expected.

So how do I fix this?  What am I doing wrong (probably a lot of things)?   My goal is to have my subject lit and the background totally blacked out.

Thanks.


----------



## analog.universe (Oct 30, 2011)

In order to have the subject lit and the background black, you need lots of light falling on the subject and very little or none on the background.  If you're bouncing off the ceiling you're lighting the background as well.  Ideally you want to use something like a softbox and possibly even a gobo or barn doors to create light that is soft, but still prevented from reaching the background.  Increasing the subject to background distance makes this easier as well.  If it takes 4.5 and 1/640 to eliminate ambient, I'd suggest turning the ambient down maybe?  I have plenty of shots where I've blacked a background at 3.5 and 1/200.


----------



## Trever1t (Oct 30, 2011)

decrease your ISO to native and stop down your aperture until your ambient is 3 stops under exposed at or below your sync speed. shoot thru a diffuser of sorts at a lower power to illuminate your subject, not the whole room. Just a beginner strobist here but that's my best guess. 


edit: I see I am too slow to type


----------



## Kerbouchard (Oct 30, 2011)

Put more distance between your subject and your background and try feathering your flash away from the background.  You can also lower your aperture to around f/8 or so.


----------



## jwbryson1 (Oct 30, 2011)

Newbie mistakes I'm making.   This is a really small room and my subject is about 12" in front of the backdrop.  I have very limited space to work and 4 windows behind me with honeycomb style window fittings which are lighting the room more than I'd like.

I like the idea of shooting at 1/200 and stopping down the lens.  That is so obvious but I did not think of it.  I also understand the subject needs to be farther away from the backdrop.  Thanks for the reminder.

Newbie back to work now.  Thanks.  Maybe I'll post some results later today.

EDIT:  I adjusted my f-stop to f/14 and I can now shoot at 1/80 and totally eliminate the background.  Thanks for the help.

EDIT 2:  Here's what a newbie I am.  I didn't bother checking my ISO before I did my initial settings at f/4.5 and 1/640.  It was still at ISO 800 which is the setting I was using at a Halloween party last night.  Silly mistakes.


----------



## BuS_RiDeR (Oct 30, 2011)

As far as I know.... When using flash or strobes with your camera's sync speed... That will help you get a proper exposure. 

I suggest a smaller aperture (start with /f8.0 or even smaller.

Another option might be to move your backdrop back, a bit more away from the subject.


----------



## Trever1t (Oct 30, 2011)

Definitely move your subject as far forward as you can and still keep the composition. 12" is too close.


----------



## jwbryson1 (Oct 30, 2011)

Yeah, I'm going to move the backdrop to another room.  I'm having to dance around a moderate size piano and some floor lamps to even get a shot.


----------



## Jan Matis (Oct 30, 2011)

You can still use faster shutter speed. You need to be on full manuall mode. more for example on lightenupandshoot.com


----------



## gsgary (Oct 30, 2011)

jwbryson1 said:


> Newbie mistakes I'm making.   This is a really small room and my subject is about 12" in front of the backdrop.  I have very limited space to work and 4 windows behind me with honeycomb style window fittings which are lighting the room more than I'd like.
> 
> I like the idea of shooting at 1/200 and stopping down the lens.  That is so obvious but I did not think of it.  I also understand the subject needs to be farther away from the backdrop.  Thanks for the reminder.
> 
> ...




Shut your curtains


----------



## jwbryson1 (Oct 30, 2011)

Jan Matis said:


> You can still use faster shutter speed. You need to be on full manuall mode. more for example on lightenupandshoot.com



I was in full manual mode.


----------



## jwbryson1 (Oct 30, 2011)

gsgary said:


> jwbryson1 said:
> 
> 
> > Newbie mistakes I'm making.   This is a really small room and my subject is about 12" in front of the backdrop.  I have very limited space to work and 4 windows behind me with honeycomb style window fittings which are lighting the room more than I'd like.
> ...



Don't have any.


----------



## indioli (Oct 30, 2011)

pin a throw over the windows?


----------



## KmH (Oct 30, 2011)

jwbryson1 said:


> gsgary said:
> 
> 
> > jwbryson1 said:
> ...


Improvise.


----------



## Derrel (Oct 30, 2011)

We used to use Foam-Core boards as window-blockers.


----------



## jwbryson1 (Oct 30, 2011)

I changed my settings to f/14 and at that aperture I was able to shoot as low as 1/80 and block all ambient light.  My seriously stupid rookie mistake it forgetting to check all of my settings before taking the shots.  I got so excited with my new gear (backdrop, etc.) that I just wanted to start shooting and I made dumb errors.  

But, now I know.


----------



## Trever1t (Oct 30, 2011)

Cool!  Now bump up your speed and open the aperture a bit


----------



## Jan Matis (Oct 30, 2011)

jwbryson1 said:


> Jan Matis said:
> 
> 
> > You can still use faster shutter speed. You need to be on full manuall mode. more for example on lightenupandshoot.com
> ...



(that's my punishment for trying to help without re-reading it. ) Despite I shoot with Sony, I will continue  

On my a77 (and my old a700 too) when you have flash on hot shoe to be allowed hss (high speed sync) the flash needs to direct forwards on 90 degree angle (in any different angle hss will not activate and shutter speed is limited to 250). 

I do not know nikon at all and I also do not know whether you had some radio triggers or use some equivalent of sony wireless-light-morse-code  where on-camera flash configures and triggers off camera flash. But the point is - if you use radio triggers try to angle fash to point 90 degrees forward as if it was on hot shoe. ( just a quick sanity check - your wireless radio triggers also have to be hss compatible )


----------



## jwbryson1 (Oct 30, 2011)

Here's what I got SOOC.  Shot to JPEG + RAW.  No editing done.  Just trying to get effect of blacked out background.  It needs work but closer than when I started.


----------



## joealcantar (Oct 30, 2011)

jwbryson1 said:


> Here's what I got SOOC.  Shot to JPEG + RAW.  No editing done.  Just trying to get effect of blacked out background.  It needs work but closer than when I started.


-
Lift the lights above the subject so the shadows fall down at about a 45 degree angle.
Turn her face a little more so you get a 2/3 view of the face.
Looks like both lights are set the same , turn one off and get the settings and lighting right with one light on side main side of face and then bring in your second flash/light and fill in the shadow/fill side of the face gently.  Looks like you have a flash on the camera if so and not filling in shadows properly use a reflector NEAR the face to fill in shadow area. 
Lift the hat a little the shadow cutting into the eye is distracting.
-
Shoot well, Joe


----------



## jwbryson1 (Oct 30, 2011)

joealcantar said:


> jwbryson1 said:
> 
> 
> > Here's what I got SOOC.  Shot to JPEG + RAW.  No editing done.  Just trying to get effect of blacked out background.  It needs work but closer than when I started.
> ...



Thanks.  That hat's a little big for her and kept slipping down.  This was shot with one SB-700 off camera, camera left about 30 degrees and bounced off the ceiling.  My D90 was in commander mode and set so the on camera flash was not supposed to flash, but my daughter said they both flashed.  I thought she was mistaken because I had set it not to go off.  It sounds from your post, Joe, that you think 2 flashes were used too?  I need to check that--not sure why the on camera flash is firing.


----------



## Kerbouchard (Oct 30, 2011)

There are a ton of ways to get a black background.  Here is an example of one done at the local park.

http://www.thephotoforum.com/forum/...49679-havent-posted-images-here-while-so.html


----------



## Derrel (Oct 30, 2011)

You're making it REALLY tough on yourself with that hat pulled down so far on her forehead !!

The light coming in from the left side of the camera is casting a hard shadow of her nose on her cheek. Overall, the exposure seems quite a bit under-exposed.


----------



## joealcantar (Oct 30, 2011)

If you are using commander mode set the preflash setting to "--" it will fire the pre-flash but not a flash that will affect the shot.  I saw two catchlights is why I was thinking you used two flashes.  
-
Shoot well, Joe


----------



## Tiberius47 (Oct 30, 2011)

jwbryson1 said:


> I set up my new black backdrop, put my camera in manual mode and adjusted the setting to f/4.5 and 1/640 shutter speed which totally eliminated all signs of the backdrop and all ambient light which was my goal.  I put my subject in front of the backdrop, took my SB-700 off camera and angled it to bounce light off the ceiling.  When I took the shot, however, the shutter speed was 1/200 which is my D90's flash sync speed, and of course the lighting is a bit hard, the backdrop appears and there are shadows.  Not what I wanted or expected.
> 
> So how do I fix this?  What am I doing wrong (probably a lot of things)?   My goal is to have my subject lit and the background totally blacked out.
> 
> Thanks.


 
You're bumping up against the camera's flash sync speed.  Basically put, if the flash is going to work, then it needs to be at a point where the whole sensor is exposed at the same time, and with faster shutter speeds this doesn't happen because of the shutter construction.  You can use high speed synch (sometimes called FP mode) if your flash has it.

To get the background to drop out, move the subject away from the background, move the lights as close to the subject as you can and dial the power down to the minimum you can while still getting enough light for your shot.  Because of the way light falls off, very little light will reach the background.


----------



## jwbryson1 (Oct 30, 2011)

Derrel said:


> You're making it REALLY tough on yourself with that hat pulled down so far on her forehead !!
> 
> The light coming in from the left side of the camera is casting a hard shadow of her nose on her cheek. Overall, the exposure seems quite a bit under-exposed.



Agreed.  That hat is a bit too big for her head and kept slipping down.  I was having some fun and trying to figure out the black background effect and trying to direct her as well.  She was more interested in being late for the start of Sponge Bob so I had just a few minutes to get a shot.


----------

