Flash to subject distance

merv

merv

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Setting up my interfit EX 150 studio lights at home and have a couple of queries.
Is there a typical flash to subject distance to achieve a balance between adequate lighting and not making the subject feel hemmed in?

ALSO
I have followed intermits DVD tutorial to the letter and set the soft box for f8 and the umbrella a stop less at f5.6 using a Seconics light meter.
The camera is set up with FLASH WB, Manual exposure with f8 and 1/125 sec and ISO 100.
Flash to camera distance is about 4 ft.

With these settings the pics are well over exposed and i have to set the camera to f 13 to get the histogram in the middle.
Is reducing the exposure on the camera the right way to handle things? Maybe the lights are too close?
Maybe the lights should be set for f11 and f8 instead of f8 and f5.6?
Any advice would be appreciated
merv
 
It's not unusual for there to be a difference, and the histogram is the ultimate arbiter, but that's a bit much.

Not enough info though. What kind of softbox, distance to subject (you've said to camera :thinking:), what power setting, how are you taking meter readings, what tone value in the subject is in the middle of the histogram?
 
Hi Richard - you'll have to go easy on me here this is my first venture. It is an Interfit soft box 60 cm square.
Sorry meant to say distance from FLASH TO SUBJECT 4 FT. Main light (soft box) is at max power and umbrella (fill) is at half power.
Measured flash light using cord flash mode and set each light separately.
Sorry not sure how to answer your question about tone value.
Is there such a thing as a typical distance from flash to subject, in other words an optimal value?
Thanks
 
Okay, but I should ignore the Interfit instructions, they're just ballpark and it's what you're getting that matters and f/8 sounds a bit low from what you've said.

4ft isn't a bad kinda distance. You don't want to give your subject claustrophobia, but it's the quality of the light you're after. Move the light closer and it gets bigger relative to the subject, therefore softer (shadows are lighter and less sharply defined). If you want the same softness but with more distance, you need a bigger softbox, and also more power to maintain the same exposure level.

Metering. With the white dome in place, the meter should be right against the subject, and for a final overall reading (all flash units on), aiming at the camera. Distance is critical and small changes can make more exposure difference than you might think. It's not uncommon for there to be a difference between what the meter says and what's on the histogram, especially at higher f/numbers where lens apertures can vary a bit. But the meter is making a lot of assumptions on what happens to the light after it hits the lens, and there are quite a few variables that it knows nothing about, hence the potential for error.

Go by the histogram - that's what you're actually getting. Caucasian skin tone should be a bit to the right of centre; a white shirt should be on the right; a dark top to the left. Only mid-grey should be in the middle.

You can adjust exposure levels any way you like. The ideal procedure is to position the lights as you want them, select the lens aperture to control depth of field, low ISO for best image quality, and then adjust power output for correct exposure. With luck, that will be within the power range of the head/s, but if not you've just got to juggle things for the best compromise.

HTH :)
 
Thanks Richard thats very well explained - and the spellings very good!
I am happy with my results with f13 on the camera and 8/5.6 on the lights.
Haven't actually taken them into PP yet to see what they look like on the computer but will do now.
Thanks for your help
merv
 
merv said:
Thanks Richard thats very well explained - and the spellings very good!
I am happy with my results with f13 on the camera and 8/5.6 on the lights.
Haven't actually taken them into PP yet to see what they look like on the computer but will do now.
Thanks for your help
merv
Click to expand...

Sounds good :thumbs: F/13 is a bit high if you're wanting best sharpness and don't need that much depth of field, but not a major issue for now.

spellings spelling's :D
 
OK Dont rub it in!:'(
The histogram is very narrow and tall. With camera at f8, same as main light, it is well over to the right. At f13 it is just right of centre. Maybe settle for f11. Suppose experimentation is the order of the day.
Have been asked to shoot a friend of my daughter with her two twin girls and that is why Im putting myself through this. Good training though! At least it gets the gear out of the box. Maybe I'll end up shooting myself.
Will shoot RAW to give me the best chance of recovering the image if over exposed. I suppose if I watch the histogram they won't be overexposed.
Thanks again
merv:clap:

:nikon:
 
Richard I might as well use your knowledge while you're available.
Is studio photography normally tripod based or can hold the camera to give me a wide variety of angles and perspectives? I would have though the tripod only would be a little restrictive. I assume in flash that the shutter speed is not critical from the aspect of somebody moving?
I have an 85mm prime which I believe is a good portrait lens but I'm sure a zoom would also be useful for composition purposes. I have a 24-70 and 24-120 but optically the first one is the best.
merv
 
merv said:
Richard I might as well use your knowledge while you're available.
Is studio photography normally tripod based or can hold the camera to give me a wide variety of angles and perspectives? I would have though the tripod only would be a little restrictive. I assume in flash that the shutter speed is not critical from the aspect of somebody moving?
I have an 85mm prime which I believe is a good portrait lens but I'm sure a zoom would also be useful for composition purposes. I have a 24-70 and 24-120 but optically the first one is the best.
merv
Click to expand...
have a look here lots of basic stuff to be getting on with hth mike

http://www.youtube.com/results?sear...02.9.9.0...0.0...1ac.1.11.youtube.DTR6s8DLRNQ
 
merv said:
Richard I might as well use your knowledge while you're available.
Is studio photography normally tripod based or can hold the camera to give me a wide variety of angles and perspectives? I would have though the tripod only would be a little restrictive. I assume in flash that the shutter speed is not critical from the aspect of somebody moving?
I have an 85mm prime which I believe is a good portrait lens but I'm sure a zoom would also be useful for composition purposes. I have a 24-70 and 24-120 but optically the first one is the best.
merv
Click to expand...

A tripod can be useful if you want to engage better with the subject, but mostly studio work would be done freehand or using a monopod as it allows more expression and different angles to be used. Using studio gear at the kind of apertures you're using all of those lenses will produce stunning results. You could try just using the modelling lights and shooting wide open with your prime though.
 
Thanks Dean for that. Your suggestion about shooting with modelling lights only wide open - would I need to engage auto ISO just in case?
 
Well, I'd never use auto ISO personally, but with a D4 I'd just stick it on about 800 and see what kind of shutter speed you get. If you get around 1/250 you'll be just fine - less if you have steady hands!
 
merv said:
Richard I might as well use your knowledge while you're available.
Is studio photography normally tripod based or can hold the camera to give me a wide variety of angles and perspectives? I would have though the tripod only would be a little restrictive. I assume in flash that the shutter speed is not critical from the aspect of somebody moving?
I have an 85mm prime which I believe is a good portrait lens but I'm sure a zoom would also be useful for composition purposes. I have a 24-70 and 24-120 but optically the first one is the best.
merv
Click to expand...

You certainly don't need a tripod from a technical standpoint - flash duration is your effective shutter speed and that's fast enough to fix camera-shake, if maybe not freeze kids jumping around. A bit of freedom of movement is nice of course, but you may have less scope than you think. Changing camera angle, or if the subject moves too much, and the way the shadows fall will change (less so with softer light that's less directional) and you may 'run out' of background.

Shooting with a fast prime is good technique, wide open for super-shallow depth of field. Focusing can be tricky (must be on eyes, or nearest eye) and you may not be able to turn the flash down low enough to get f/1.4-2ish - hence the suggestion to use just the modelling lights, and that can work well. Set white balance to tungsten, kill all other room light, and you may have to push the ISO a bit* but your D4 will eat that :)

*No auto ISO, as Dean says, use manual for all settings
 
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Sounds to me like you're setting/measuring the lights individually. In the final exposure where the lights overlap the lighting will combine for a brighter final exposure. Your lights are set at a 1:2 ratio (1 stop difference) simply setting them to 5.6/4 should put the camera closer to f/8.
With a 4ft lighting distance subject placement is fairly critical...simply changing position by 1ft (i.e. changing pose) will change the exposure by almost 1 stop. That's why big lights with big modifiers are "better." They can be placed further away for the same quality of light with less falloff.
 
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