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ABR800 Ringflash - Subject Distance?
So, I've been messing around with the ABR800, but I'm not getting quite what I'm looking for. I want major falloff starting at the edges of the body, and I'm hoping for a bit more 'pop'. Pretty much the standard 'ringflash' look. I've been using the Moon Unit, which I feel may spread the light too much. So, will using it bare (or with included diffuser) help this issue? Can anyone tell me what their general subject to flash distance in a case like this? I don't have any photos to reference at this time, perhaps someone could post some with their answer? Mar 28 07 11:12 am Link EJH Photographics wrote: If you want falloff and contrast use it bare and close. Use as short a lens as practical (50mm?) The inverse square law dictates the light falloff and the relative size of light source affects contrast. Mar 28 07 11:17 am Link I suppose that would make sense as well. I have been using my beloved 85mm, but I feel I have to pull back too far with it. dDavid wrote: Mar 28 07 11:20 am Link Here's one I took with a ringflash that I think shows the falloff you're looking for:  This was done with a Hensel ring, but the hensel is about the same size 'n all of the ABR unit. Try the ABR with just the standard reflector and see if you like that better. I took the above picture with a 28-75 zoom lens on a 1.6x crop camera, and if I remember correctly I wasn't more than maybe 8 feet from her. As you can see, the sides of her arms are quite a bit darker than the surface that is parallel to the lens. This is one of the things that creates the ringlight "look". Also, her face is overexposed, but the light falls off pretty quickly as her body gets farther away from the lens. Her booty is probably around 2 stops dimmer than her face. Maybe I'm not answering your question at all, I don't know. Try it without the moon unit and see if you like that better. Here's one using the ABR800 with just the standard reflector, but no diffuser. The effect isn't as pronounced because I was competing with midday sun in Las Vegas. I was crouched under the next handrail, so the distance from me to her was the same as the distance from her to that next rail in the background. It was damn bright out there, but I think the ABR did OK, all things considered.  Mar 28 07 11:27 am Link EJH Photographics wrote: Ummm...I don't want to sound like a smart ass, but by FAR the best way of finding out how the unit works is to use it in all of its various configurations. Get a model and give the sucker a proper test drive...the light, not the model. Mar 28 07 11:33 am Link Just looking for a bit of a.. roadmap? So I'm not going in the wrong direction. Olaf S wrote: Mar 28 07 12:59 pm Link Larry, you've hit the nail right on the head! The first photo is exactly what I'm talking about. I was assuming that if I backed up as far as 8 ft, it would simply blanket both the subject and the background with light, and I wouldn't get the falloff I was looking for. I seem to be incorrect? LarryB wrote: Mar 28 07 01:05 pm Link EJH Photographics wrote: Not quite sure I understand what you're asking. Look at this: Mar 28 07 02:25 pm Link I think my confusion lies with the falloff distance itself. I wanted the light to falloff quickly, in a short amount of space. I place a model 3 feet from a background. I want the light to disperse at least 2 stops no farther than 3 feet behind the model. So I placed myself, and my ringflash, less than 3 feet in FRONT of the model. This, however, has the effect of lighting up the model intensely, and didn't seem to get the 'ringflash' look. It seems, though, that I should be moving back instead? My fear was that if I backed up to 10 feet from the model, the BG would still be 3 feet behind her, and significantly brighter, which is not my intention. Mar 29 07 03:35 pm Link I don't understand why you don't just try it bare and with a short lens. Easy and fun way to learn. Mar 29 07 03:56 pm Link @ EJH: Please tell me: 1: What camerahouse are you using (full-frame, 1,6 crop factor, or other ?) 2: What motiv/subject size are you gonna shoot (full-figure, 3/4, other ?) 3: Which lenses do you have ? post here, or PM me, then I'll be happy to draw you a roadmap ;-) Marco/ Aug 16 09 04:46 pm Link EJH Photographics wrote: This actually makes perfect sense. Perhaps the way to do this is not just to you have you move back with the camera & light, but to move the model along with you as well? Cause right now it just sounds like 3' of space between the background and your subject just isn't enough. It may simply be simple physics and an inevitable move you'll need to make. I would think you'll just need to compromise here, though I too would love to hear if there's a way to go around this. Aug 16 09 09:02 pm Link maybe you should try it with a grid.......I think that is what you are looking for Aug 17 09 06:30 am Link I agree with Stan; use the 20 degree grid. Drop the diffuser, that will only make you loose "pop". And the moon unit only makes light softer. With this on, your fall-of will be much more smooth and graduated, so forget about that too... "Pam with Butter" cooking spray is also said to be good for that extra "pop" ;-) To calculate the working distance ( = subject to flash distance ) you need more factors. But lets say your gonna shoot a 3/4 of a model, and that she, from mid thigh to just over her head, measures 120 cm. With a 135mm lens on a fullframe body, you would then be shooting at appx 540 cm [ 120 cm model / 3 cm sensor ( for a 85 % fillout) = a factor of 40 and factor 40 x 135 mm = 540 cm ] AB state that the ABR800 gives you f/16 at 10 feet (@ ISO 100) 540 cm is about 18 feet. You know the rule; "if you double the distance, the light becomes one quarter" So f/16 becomes f/8 ! This will not be enough to overpower the sun at the beach. You could use it as fill - one to two stops under the sun - and it'll also be fine in a controled studio environment, If your job calls for overpowering the sun, then you wanna use the Zeus Ringmaster, which AB state can give you an output of f/45. The Zeus would at 18 feet most likely be able to give you just about f/22½ and there by one to two stops more than the sun. Finally: for optimum fall-of, use a dark studio, or large black panels (subtractive fills) as close to the model as possible. I hope this is usefull, ortherwise feel free to PM me ;-) Marco/ Aug 19 09 04:07 am Link |
