test@here.goes), July 22, 2001.
Light loss with umbrellas?greenspun.com : LUSENET : Advanced Photography : One Thread |
Ok so how about an actual question here. I've been looking at umbrellas for a simple studio lighting setup and I haven't found any information on the approximate light loss you can expect. I know it depends on if it's white or silver, so let's assume it's white. I'm sure it depends a lot on the exact equipment in use, but should I expect something in the 1 stop range (in which case even a small "shoe mount" head would be usuable) or 3 or more stop range. True to the forum here I've browsed quite a few manufacturers web sites and catalogs, but haven't found any numbers on this.
-- Bob Atkins (bobatkins@hotmail.com), July 27, 1999
Light loss compared to the light pointing straight at the meter? The average is probably around two stops, but as you already know it depends on the material of the lining of the umbrella: plain white, zebra (alternating panel of white and silver, or just silver. It also depends on the size of the umbrella, the angle of the light beam from the head, reflector being used on the head, etc. For example a vivitar 283 pointed into a 20" umbrella is going to be more efficient than if it were pointed into a large (50") umbrella, but the converse might be true if you are talking about an Elinchrom EL1000 as a light sourse. On the whole I recommend you look at a small or a medium sized (say 30"x40") softbox instead of umbrellas for general photography. In umbrellas I like Photek Goodlighters; in softboxes I like Plume Wafers, Plume Worldbanks (also availible as Calumet Illumina) or Chimera.
-- Ellis Vener (evphoto@insync.net), July 27, 1999.
I'm not sure I understand how a small umbrella can be more efficient than a large umbrella, unless they diffuse light over a smaller angle (I haven't found a good book which explains any of this, even though I've browsed most of the contents of the local Borders bookstore!).I guess the advantage of an umbrella is portability. Lugging around a softbox sounds like a pain, even if they do give better light. I don't have a home studio (as you know, I'm not a studio photographer), but when I go somewhere and someone says "Take a picture of me", I hate the results I get with on (or slightly-off) camera flash, even with a small diffuser (Shell) or bounce. The diffuser helps quite a bit over straight flash, but it's still hard to get nice results (or at least results I like, other people seem happy though...).
I've seen some small softboxes from Calumet (12x16?), which can actually be mounted on a flash bracket, but the whole outfit looks a bit clumsy and top heavy, and I'm not sure 12x16 is really big enough to significantly soften the light anyway unless it's really close to the subject. I was hoping that a ~36" umbrella in combination with an off camera 540EZ might improve things a bit and still be relatively portable, while still giving me enough light to work with reasonable apertures and without having to resort to fast film. The diffuser gives me about a 2 stop loss - which I can live with - so it sounds like an umbrella wouldn't be much worse than that.
-- Bob Atkins (bobatkins@hotmail.com), July 27, 1999.
A lot depends on whether you will shoot through the front diffusing material of an enclosed umbrella, straight bounce by pointing the strobe at the back with the front open or bounce by pointing the strobe at the back with a diffusing screen(or material) over the open front. You will lose 1-3 stops of light with bounce from the back, and 2-4 generally from back bounce coupled with front diffusion. If you shoot with front diffusion with the strobe inside the umbrella place right at the back you won't really get much effect from all the reflective material inside. But get a flash that acts as a 'bare bulb' and you will get a softer quality of light and only lose 1-3 stops(unless your diffusion is heavy). I have successfully used a Metz 60 series strobe off with an umbrella without diffusion over the front by pointing the head into the umbrella while keeping the flash sensor built into the handle pointed at the subject. Works well and with so much power available with this flash I didn't miss the stop and a half I lost. With a lower power flash this particular umbrella combination was useless for anything but the barest of fill flash. I did find this combination useful for my needs. I did take flash & meter to a photo shop(Calumet) and tested it in the store before buying it. Their cooperative attitude helped me decide what would work. They even encouraged the test and provided a few sheets of Polaroid so we could see how it would work. Wish more shops were as open.
-- Dan Smith (shooter@brigham.net), July 27, 1999.
Bob, I find that well made soft boxes are't that much of a hassle to use, but they are a lot more expensive. You should look at the Photek Goodlighter umbrellas if you are using flashes of 250w/s or more. A small umbrella used with a small strobe (Norman 200B, Lumadyne or smaller is going to be more efficient that a large umbrella because the light is more concentrated. having said that, I like the lighting effect from larger sources, and I agree a 12"x16" light source just isn't big enough to make a difference over direct light for me, unless I am photographing something small and lighting it from a close distance.
-- Ellis Vener (evphoto@insync.net), July 27, 1999.
I hope it's ok to post a question about a question.Bob, why do you care(I don't mean this in a flippant way)? It seems that if you're using a flash meter any light loss wouldn't matter. Are you using a flash meter?
-- Paul Wilson (pauldwilson@mediaone.net), July 30, 1999.
I have a flashmeter (Autometer IIIF) and use it sometimes(!). My main concern is that with a puny little shoe mount flash (Canon 540EZ), if there's too much light loss I'm left shooting wide open with no DOF, or putting the light really close to the subject. I can see that when shooting with 2000WS monolights a few stops loss here and there is no big deal, but with a marginal flash it's quite important.I could try a silver umbrella to reduce losses, but then I wouldn't get as much diffusion. As usual with all amateurs, I'm trying to get something for nothing via the cheap route using totally inadequate equipment and expecting professional results! The real answer is "buy a decent monolight (or two)" I suppose. Maybe this does belong in the original Q&A forum after all...
-- Bob Atkins (bobatkins@hotmail.com), July 30, 1999.
Oh. That makes sense. I though you were trying to determine exposure.How about getting a few cheap, used flashes(like a Vivitar or something), and then strap them together so they're both pointing into the same umbrella. You can then sync them with a PC cord and maybe get enough light.
Obviously it's not ideal but it may work.
-- Paul Wilson (pauldwilson@mediaone.net), July 30, 1999.
Bob, If it was my money. I'd get a small pack and head combo like the 500w/s Dynalite kit or Philip's brand of choice Novatron. Since the heads are lighter you can use lighter weight stands if you choose too, but more importantly you get more flexibility and system redunancy for a better price. I would both a pack & head system (a mix of Norman & Speedotron) and a couple of monolights (Elinchrom).
-- Ellis Vener (evphoto@insync.net), July 31, 1999.
Bob your post spurred me into action. I am photographing some sterling silver jewelry for a neighbor client. After not being able to get the light I wanted with my big tools, I went and bought the Chimera bracket for using a speedlight (A Nikon SB-25 to be exact, but my remarks apply to other brands of dedicated TTL/OTF speedlights as well) and am using that as my mainlight source. I am using an 80-200mm f/2.8D lens with extention tubes with an N90s and F5 bodies, and my film is RVP. Since my flash is TTL metered, I don't have to worry about using a handheld meter or figuring extention factors. This set up works extremely well!< /P> Thanks for giving me the spark that led me to think of a creative solution.
-- Ellis Vener (evphoto@insync.net), August 08, 1999.
I have a pair of 540EZ's that I have used with the EOS TTL wires, shooting into a pair of Eclipse umbrellas, with a photoflex clamp mount, on Bogen stands. I use this set up when I want easier portability than I can get with my Photogenic 1500Rs. I can get the whole outfit into a Bogen light bag, and take it to locations.I generally shoot NPH 400 or NHG II 800 with this set up. Even then, depending on ambient light, I often have to slow synch. I wouldn't be very optimistic about shooting ISO 100 or slower slide film with this set up, but if you can set up close enough with a pair of 540EZ's, it could be done. FWIW, my sense is that you lose 2 to 3 stops into an umbrella as a general rule of thumb.
-- Glen Johnson (gjohnson@engr.udayton.edu), August 19, 1999.
-- (test@here.goes), July 22, 2001.
Alright, another question on a question. I use a Novatron 1500 in my studio so I have enough power.....BUT... lets talk about fill flash outdoors. I wanted to soften my flash outdoors so I used a small umbrella (silver) and mounted my 2 vivitar 285s on a homemade bracket that held the 2 flash units side by side and also mounted to a light stand. I used a long sync cord connected to one of the units and a slave on the other. I tested this unit on a bright day about 3:00 because this is the about the earlist time of day I shoot weddings. I had hopes that this would really work for outside fill-flash. My testing revealed that there was not enough power for a varity of f- stops so I abanded the idea, Maybe, I'll try again. Maybe, I'll try shooting through my homemade diffusion panel that I love in my studio. Any ideas? Zack
-- Zack (cpl_texas@hotmail.com), September 28, 2001.
Bob,I've been using a Westcott 32" plain white umbrella (no backing) with a 550EX or a 540EZ as a main light indoors. I lose 3 f-stops with the umbrella. I get f/8 with the umbrella at 5 feet and flash at full power, with 100 speed film. Outside, with the speedlite and umbrella as a main light, and ambient as fill, I'm getting f/8 at 1/4 power and the umbrella at 5 feet. So it is doable. I've been using pc cord and manual flash, since I don't have the second 550EX for wireless E-TTL capability.
-kevin
-- Kevin M. Allen (kevinmallen@worldnet.att.net), February 10, 2002.