Studio Lighting at wide apertures

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GaryK26

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Ok, so this is probably a really dumb question, but here goes....

When shooting portraits in studio with white background blown out, I meter f8 for key and around f11 or just under for the background.
Now what if I want to create some shallow dof shots around f2.8?
I can lower the output from the flash heads, but surely wouldn't ambient light start playing a major factor.

The space that I have is upstairs in a commercial unit and the room lighting is shared / on the same switch as the adjacent space that is used for other purposes, meaning that I cannot lower or switch off the room lights.
 
cover / remove the lights that will affect you!

THe whole part of a studio is that you control the light....
 
If you're shooting at 100ISO it would need to be very bright lighting to have an impact. It's easy enough to check though, just remove your flash trigger and shoot a frame.
 
Thanks for the quick replies.
I guess giving it a try as Phil suggests would be a good starting point.

I did a bit of googling on the subject and all that I could find was people asking about how to deal with too much flash (with heads on lowest setting), to which responses were generally using ND filter or gels on the heads.
Having said that, I'd be surprised if you couldn't lower the output enough and move the heads further away.

Anyway, next time in my makeshift studio I'll check the effect of the ambient.
 
Turning studio flash down low enough for like f/1.4 or something is difficult.

- One easy solution is to just shoot by the modelling lights, but you must kill all ambient. That's what I do, works fine.
- Fit an ND filter to the lens, which has the advantage of not needing any ambient to be lowered. Anything more than about three stops ND makes the viewfinder quite dark.
- ND gel the flash heads. Bit of a fiddle, and you still have to kill the ambient.
- Move the lights way back. Changes the lighting effect completely. Have to kill ambient.

On the other hand, one of the reasons for super-shallow DoF is to blow the background out of focus, which if it's pure white will make no difference.
 
Loads of options, from turning down the lights, filtering them and / or the camera to moving the lights back, making them bounce more, using more black bounces.

Paul.
www.photographybyriddell.co.uk
 
Studio lighting at f1.4 is actually pretty easy..... Use just the modelling lamp - job done ;)
 
This was shot with 400W studio lights turned all the way down and a ND filter used on the lens to get f1.8 (Or 2.8, can't remember).

The ambient light won't creep in indoors at 1/125sec. Close the curtains and turn off the lights if you want to be extra cautious.

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Inside your average room (without daylight) your settings will be something like f2.8, 1/20thsec at ISO1600

So compare that to f1.4 1/160 at ISO200 (100 is better if you need it)

f1.4 is 2 stops brighter than f2.8 but 1/160th is 3 stops darker and a further 3 stops darker with ISO200

So overall you are 4 stops darker than ambient which should pretty much be black.

Adding the flash or modelling light means that is the only thing lighting the subject.
 
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Finally going to get a chance to pop into my makeshift studio tomorrow and will definitely being giving a try to if ambient is going to be intrusive.
If it is, then I'll just around f5.6 / 8 or as wide as possible whilst being able to keep the ambient out of the mix.

I think that some of the responses are missing the point, but I DO appreciate the input.
The point being that it is not practical / possible to turn the lights off - it is a shared space on the upper floor / loft space of a retail unit (with stud wall partitioning, but the lights are above the partitions and are on the same switch).
I'm not even having to pay for using the space, whereas the other side of the space is being used as a pet grooming parlour and is being paid for by the grooming parlour owner.
 
Shutter speed controls ambient light at any given aperture. In a studio you will not need to worry about ambient!
the light distance (to subject) and power will most likely be more limiting. A 400W light close up will likely determine your aperture (even at lowest power it could be f5.6)

Maybe you are missing this but the lights in the ceiling will likely have absolutely no impact on your shots. What your eyes see as bright is not the same as the cameras. In fact it's useful to leave lights on to assist with focusing.
 
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Jim, you maybe making this more complicated than you think, just stick an ND filter on your lens, job done.

No mucking about moving lights and having to deal with the effect that has on the image, or even putting gels on the lights themselves is a pain IMHO, and still won't help with the lights in the ceiling that you have to leave on.
 
My point is you dont really need to much around at all. To shoot with the wide end of the lens just use the modeling light. :)
 
Had a play with shooting at 2.8 yesterday and am pleased to say it was relatively successful - work in progress...
Did as Phil suggested, turned off all flash and took a shot at 2.8 ISO 100 and result was virtual darkness (image), meaning that the ambient shouldn't cause any problems.

Next challenge is getting the flash heads set up - they are all 400Ws and the lowest I could get yesterday was 5.6 on key light (with softbox).
I think I have an inner difuser for the soft box somewhere and that should help bring it down, but the easiest way is going to be moving the key back.

I don't have an ND at the mo (maybe Santa will bring one), but appreciate that ND is probably the best way to go so that I dont have to faff around moving the lights when switching between f8 and f2.8.
So that I don't need to change the flash output, would I need a 2 or 3 stop ND (I think a 2 stop, but not sure)
 
Using a ND filter is by far the best way of doing it. Fitting an inner diffuser to the softbox won't reduce the amount of light, it will just spread it around a little bit more, and change the quality of the light.
And moving the light further back will change the quality of the light too.

Note: By "change the quality of the light" I mean just that - it won't necessarily be either better or worse, but it WILL be different.
 
mike weeks said:
Inverse square law? move lights back a bit?

Mike
Click to expand...

Hi Mike,

Whilst you are absolutely correct, my thinking is that if I meter and start shooting at f8 and then want to open up to f2.8, instead of having to move the lights back and re-meter, I could simply screw an ND onto the lens - no moving or re-metering of the lights.

What I am not sure about though (me being dumb!) is would I therefore need a 2 stop or 3 stop ND? I think it would be a 2 stop, but not sure - can anyone advise?
 
GaryK26 said:
Hi Mike,

Whilst you are absolutely correct, my thinking is that if I meter and start shooting at f8 and then want to open up to f2.8, instead of having to move the lights back and re-meter, I could simply screw an ND onto the lens - no moving or re-metering of the lights.

What I am not sure about though (me being dumb!) is would I therefore need a 2 stop or 3 stop ND? I think it would be a 2 stop, but not sure - can anyone advise?
Click to expand...

In this case, where there is some ambient light that you can't control, fitting an ND filter to the lens is the best option (see post #5). To shift from f/8 to f/2.8 is a difference of three stops, so an ND8 filter.

Edit: crossed post with Mark. Do you understand the halving/doubling relationship between f/numbers, and how that relates to the ND filter required?
 
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Just get an ND filter. I actually used two grads stacked to get the shot above, they cost less than a tenner on eBay.
 
how bad are the other lights in the location?

Seen as most of our shots are out on location with the lastolite the outside light factor can be all over the show but doesnt seem to make a shocking amount of difference.

If timing is crucial then as above, filters can be a quick fix.

This was 2.8 @ 1/125th on a moving 2 year old,
 
I agree with the comment about cheap filters - I prefer not to use filters, but where needed I try and avoid the cheaper ones that are available on places like ebay.
The heads are Calumet Genesis 400's - 1 for key and 2 for bg (although BG is not an issue here)
 
I've never used filters of any kind - will colour casts created by cheaper filters be treatable in PP?
 
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