Continuous fluorescent lighting for 4x5 format?
Never having used studio lighting, is it possible to use continuous fluorescent lighting for 4x5 format?
Ideally, I would like to set up one or two simple lights, learn the basics of lighting, in order to do some portrait photography. The reason I would like continuous lighting is that I want to easily focus, and see what I am going to get before I take the shot. I know there is another recent forum about lighting for LF, but it seemed to focus mostly on flash lighting.
Current lenses are a 210mm f6.8 & 90mm f8.
I saw fluorescent bulbs equal to 500w, 650w, and 850w. Would a couple of the 500w be sufficient, or any of the others? The price triples once you buy into 650w and 850w, but I may be willing to spend the money if thats what I need.
I would like to be able to have a larger DOF so I can have most of the face in focus.
Let me know your thoughts.
have you thought about simple 500 watt $10.00 hologen shop lights?
Yes I did consider something like that. Although I think I would have much less heat from a fluorescent bulb, and they are balanced at 5000K. The 500w version of the bulb I was looking at costs about $25, so its not too much more.
I'm more concerned about if the 500w bulb, or a couple of them, would be enough light with my 4x5 camera for my intended purpose.
yes it's possible. 3200k,2900k, and 5600k tubes are available in most sizes from kinoflo.com but they don't have as much output as other light sources. Shop lights would work for b+w or tungsten film but they are quite hot. A chinese lantern with a 500watt ECA is another option for a soft source.
The cheapest incandecent fixture with the most output for the money is the Par Can which use par 64 globes. They're what you see at rock concerts and other live events. They can be had used for cheap, $40-60 and don't spill light everywhere since the globe is recessed within a long barrel. Many globes from wide,medium,narrow,very narrow, and 1200watt "firestarter" are compatible. Most are 1000watts but 500watt versions are also available in the med and wide type.
I think I should have been more clear, and its my mistake. Here is a link to the bulbs I'm looking at LINK, the bulbs are located at the bottom of the page.
They are screw in bulbs, and I was planning on using them in a reflector.
Thanks for the input so far.
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I don't really know how this will effect film, but fluorescent lights are not generally continuous spectrum. Their emission is rather spikey. Other than that, I don't really have any comments on the type of lamps you want to use. They may work well inside a softbox that has internal reflecting material like a Rifa light (only larger).
I followed your link and looked at the 105 W 5000 K lamps. They have a CRI of 84 or 85. That would not be good for colour portraits, but it would be OK for B&W of course.
What sort of aperture and what film do you want to use?
It's difficult to give even a ball-park figure, but two of those lamps used with a basic reflector and light diffusion material might give you something like 1/30 at f/5.6 with ISO 320 film when five feet away from the subject. In Chinese lanterns you might get about the same or more likely a bit less. Omit the diffuser and gain about a stop.
I think that their incandescent equivalent values are optimistic, especially if you are comparing them to 3200 K photographic lamps. You would expect between 11,000 and 13,000 lumens from a 500 W quartz halogen lamp. Those florries are only giving out 7,000 lumens.
Last edited by Helen B; 12-02-2006 at 11:21 PM. Click to view previous post history.
Thanks for your response. What would be a good temp for color portraits (what CRI)? They sell another version that is rated at 4100K.
As far as film, for b&w using ISO 400 wouldn't be a problem. Although, when I start doing color work films I'm interested in using are ISO 160.
I would like to have the ability to stop down a little more, so I could have the head in focus if possible. The other thing is, I believe since these lights are fluorescent, I can have them somewhat closer to the subject because they are suppose to produce less heat.
Thanks for your help.
In addition to the discountinous spectrum issues, be aware that florescent light are a ballasted light source and are subject to sine wave flicker just as an HMI would be, so use safe shutter speeds. (not to much of a problem, on the slow side.)
That's just, like, my opinion, man...
This is true, good point. Because of the mercury vapour, the energy-efficient fluorescents have the characteristic spikes at 436 and 546 nm etc. This is an issue quite separate from the CRI/ white balance issue. And I found that there are very few fluorescents that don't have mercury spikes, the only ones that come to mind are the the solux bulbs.
Originally Posted by Greg_E
Anyway, my experience is that the spikes don't matter too much with most films, the spikes bandwidth is so narrow that they usually aren't as much of a problem as one might fear. But digital is another story- with digital they wreak havoc!
The other important point raised by JBrunner, the flickering, will be most relevant at shutter speeds of ~1/120 sec or faster. I think there are some fancy, more elaborately rectified power sources that solve this issue.
The bottom line is that I thought about getting into fluorescents at some point because they are cool and they seemed inexpensive. But upon more research I discovered that the ones that solve the above problems are rather pricey...
Last edited by keithwms; 12-03-2006 at 11:18 AM. Click to view previous post history.