Re: tungsten vs strobe lighting
Quote:
Originally Posted by
premortho
:rolleyes: Let me say at the outset I'm certainly no expert, which is why I keep it as simple as possible. I use photofloods in hardware store reflectors. When I use ortho film I use blue bulbs. With panchro emulsions you can use either blue or white. Blue is more like sunlight, temperature wise. While I've never used a dimmer, that seems like a good idea, as the bulbs last longer, and the model is not sweltering when you turn the "heat" on. I'll have to see if I can find a dimmer that can handle the watts. One of the advantages of using photofloods is all you need is a reflective meter. I use a Weston Master ll.
Remember that as you dim an incandescent lamp the peak wavelength gets longer (ie the light gets redder) so you are probably reducing the actinic efficiency of the lamp and thus you are likely to get less actinic power for a given amount of heat - the 'actinic watts' per electrical watt* generally goes down, particularly with ortho film. It's usually better to run the lamps as hot as they are designed for, which is why the good old P1 photofloods have a colour temperature of 3400 K (tungsten Type A) and a short, but relatively efficient (for that type of incandescent) life.
*lumens per watt isn't appropriate for films that don't match the eye's spectral response - which is just about every B&W film - but it is a guide in the absence of anything else.
Best,
Helen
Re: tungsten vs strobe lighting
Quote:
Originally Posted by
David Solow
I am shooting with a cooke 229mm lens on a 4x5 camera. I am wanting to shoot at f/4.5 to get the softest lens effect as possible. With my Bowens Gemini 500 Pro monolight set at the lowest setting, 15 watts/sec and with a one-stop reducer in the softbox, I can use only one light and must keep it around 8 feet away, otherwise the shot is overexposed. I am shooting ASA 100 at 1/125 sec. at f/4.5. I would like to be able to use fill lights, hair lights, etc. without that overexposing the film. I thought of using tungsten lighting, so I bought a 650 W Tungsten Fresnel, but with that I have to get 3 feet away at the tightest spot to shoot at the same shutter speed and aperture. I don't really want to go below 1/60th sec., and I don't want my models melting under lights so close to them. Also, the tightest spot covers less than 1 foot at that distance. With a 650 W flood, forget about getting enough light. I have done some reading on the internet already. Some suggest going up to a 2000 W Tungsten fresnel or larger, but that would mean I would have to get farther away, which would lead to loss of light intensity. Why the fresnel? I love the look of fresnel spotlights of the old Hollywood portraits of the 20s and 30s. Oh, and I can't afford HMI.
Thanks for reading my lengthy question,
David
Hi David,
I'm in a similar situation -- making portraits of my wife in a makeshift "studio", with makeshift lighting, and I've been shooting mostly at f/4, with exposures around 1/8- 1/15 second with ISO 100 film. Too much light hasn't been my problem. For my main light I use a 23watt fluorescent bulb in a 12" reflector, quite close to my subject. For fill I use a fluorescent desk lamp, with a ring bulb, and one of the IKEA LED lamps linked for an accent light. I try to spill light from my main light on the background, but it's not enough -- I need a lighter background, or another light. Anyway, that's my lo-fi setup.
Since no one has mentioned it, I will -- you could use slower film. It wouldn't be my first choice, because it would mean using Adox/Efke, but it is workable. Below are a a couple examples of my very fledgling results with the above setup -- one with Efke CHS 50 ART, and another with Fuji Acros:
[IMG]http://farm8.staticflickr.com/7061/7...b8a441bb_b.jpg Untitled by Jay DeFehr, on Flickr[/IMG]
[IMG]http://farm8.staticflickr.com/7129/6...501f0811_b.jpg Untitled by Jay DeFehr, on Flickr[/IMG]
Re: tungsten vs strobe lighting
Those are nice shots, Jay. The first one is more 1920's look (The film), The second has that plus-x look from the 1940's. And to answer Helen, I would only use the dimmer for setting up the lighting ratios, then turn up "the heat" for the shot. Now if we are using the same lights, the law of inverse squares apply to lighting so if the first light is at 6 feet and the second is at 12 feet, the second one only delivers 25% as much light on the subject. And you meter only the first lamps intensity, it controls exposure. The second light only fills shadows. But if you use two different types of light, you'll have to figure out the ratios somehow. Too complicated for me.
Quote:
Originally Posted by
Jay DeFehr
Hi David,
I'm in a similar situation -- making portraits of my wife in a makeshift "studio", with makeshift lighting, and I've been shooting mostly at f/4, with exposures around 1/8- 1/15 second with ISO 100 film. Too much light hasn't been my problem. For my main light I use a 23watt fluorescent bulb in a 12" reflector, quite close to my subject. For fill I use a fluorescent desk lamp, with a ring bulb, and one of the IKEA LED lamps linked for an accent light. I try to spill light from my main light on the background, but it's not enough -- I need a lighter background, or another light. Anyway, that's my lo-fi setup.
Since no one has mentioned it, I will -- you could use slower film. It wouldn't be my first choice, because it would mean using Adox/Efke, but it is workable. Below are a a couple examples of my very fledgling results with the above setup -- one with Efke CHS 50 ART, and another with Fuji Acros:
[IMG]
http://farm8.staticflickr.com/7061/7...b8a441bb_b.jpg Untitled by
Jay DeFehr, on Flickr[/IMG]
[IMG]
http://farm8.staticflickr.com/7129/6...501f0811_b.jpg Untitled by
Jay DeFehr, on Flickr[/IMG]
Re: tungsten vs strobe lighting
Photofloods provide good cheap fun. I run 250 watt ECA's with some household bulbs for hair and background applications. Then I have enough power left in my breaker box to turn on a space heater. Yes you're running at about 1/15th, but with a good model, it doesn't matter too much.
2 Attachment(s)
Re: tungsten vs strobe lighting
Attachment 71585All my lighting is with hot lights, I love being able to see where the light lands in real time... My assortment of lights is so basic and mixed up its embarrassing but what fun.
I have a natural light set up for still life up north, works like a charm, I just need to balance out my solarization exposure time and I am good to go.
Attachment 71584
Re: tungsten vs strobe lighting
hang a white hotel towel over the front of the softbox... that would be good for 2 or 3 stops anyway
Re: tungsten vs strobe lighting
I phrased it wrong. Turning up the heat is a photographers phrase from my youth. It means either a flash exposure or turning the dimmer on photofloods up all the way for the exposure. Running the lights on 2/3 max to set lighting ratios and sitings makes the bulbs last a lot longer, and doesn't bother the sitter (victum?) while you are doing all of this. When we were ready for an exposure, some one would say "turn on the heat". If you've ever sat under photofloods very long, you'd know what we meant.
Quote:
Originally Posted by
Helen Bach
Remember that as you dim an incandescent lamp the peak wavelength gets longer (ie the light gets redder) so you are probably reducing the actinic efficiency of the lamp and thus you are likely to get less actinic power for a given amount of heat - the 'actinic watts' per electrical watt* generally goes down, particularly with ortho film. It's usually better to run the lamps as hot as they are designed for, which is why the good old P1 photofloods have a colour temperature of 3400 K (tungsten Type A) and a short, but relatively efficient (for that type of incandescent) life.
*lumens per watt isn't appropriate for films that don't match the eye's spectral response - which is just about every B&W film - but it is a guide in the absence of anything else.
Best,
Helen
Re: tungsten vs strobe lighting
Put some diffusion or scrim(s) on your strobes. Use several layers if necessary.
Or as Rick suggested use a shoot-through umbrella. You lose half your light (one stop) regardless of which way you point it.
- Leigh