Posted: 1/20/2011 4:57:38 PM EDT
| so i'm at my kid's birthday party at one of these indoor play places where there's a bunch of inflatable jumping/sliding things. flourescent lights. the ceilings are probably 20 feet high. the action is pretty fast. i can't shoot at high shutter speed because of the poor light. d7000 with 18-200 3.5-5.6. my on camera flash is slow as dirt. the ceilings are probably 20 feet high. would a full fledged flash have enabled high speed shooting in such an environment? or is it more of a lens issue? or can this question really be answered over the internet? |
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In short, maybe. In long, depending on the lighting conditions and the energy usage requirement of the flash to properly expose the frame, the flash may or may not be able to realistically refresh fast enough to enable high speed shooting. Additionally, repeated high powered flashes can lead to permanent damage up to and including burning up the flash.
Really, depends on the situation. |
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What ISO where you using?
Have you tried a fast Prime lens? I've recently bought a 50mm F1.4 and an Sb-600 flash. The 50mm hasn't come off since I've got it and the sb-600 does get some use but not as much since the 1.4 allows me to shoot well in Low light once I bump up the ISO a bit. Try renting a lens and flash from Borrow lenses The fast 50 is pretty inexpensive and so is the flash. Nikon 50mm f/1.4G AF-S is only 30 bucks for the week. Nikon SB-700 Speedlight. is 33 dollars the SB-600 is less. So for 60 bucks you can rent both and see where you should spend your money next. Personally I love the lens much more than the flash. The 1.4 allows for some great Bokeh (Out of focus background) And I usually only use the flash for fill light or to create better lighting. |
| iso was 1600. and i should have been more clear, i was trying to stop action in focus in those light conditions not shoot a lot of pictures fast. when i bumped up the shutter speed though the pics were way underexposed and i was wondering if it was a flash issue, but i'm sort of thinking it is a situation where the zoom lens can't let enough light in like a prime would. the still photos were ok but action shots were out of focus practically every time. |
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Are you trying to get a shutter speed fast enough to stop action? Or just trying to shoot a lot of pictures in sequence rapidly?
Even with a flash mounted on the hotshoe, most cameras have a flash sync speed of around 1/200 sec for the shutter speed, which isn't nearly fast enough to stop the action if the kids are running around, etc. Obviously with a external flash, it wont be able to recharge fast enough to shoot a sequence of shots either. Your best bet is to get a faster lens, at least f/2.8 with the ISO cranked up. Not sure what your usable ISO speed is however. A f/2.8 lens is 2 stops faster than your lens at f/5.6, so if your lens is at f/5.6 shooting at 1/125 sec to get the proper exposure, the f/2.8 can shoot with a shutter speed of 1/500 and get the same exposure. |
| D7k has good high iso performance so next time crank the iso up to 3200. Also pick up a decent constant f2.8 wide zoom (something in the 17-55 f2.8 range is good) and you'll be pleasantly surprised at the outcome I think. Certainly a sb900 will do good things but the lighting will be a little harsh generally. I think a good fast lens and pushing your camera a little will do fine for you. |
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Was your exposure comp maxed out as well? embarrassed to say i'm not sure i understand this question. p.s. aekdb gonna try jacking up the iso and see how that works. the lens is looking like the ultimate answer though but i need to experiment more. thanks for all the replies. |
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Was your exposure comp maxed out as well? embarrassed to say i'm not sure i understand this question. p.s. aekdb gonna try jacking up the iso and see how that works. the lens is looking like the ultimate answer though but i need to experiment more. thanks for all the replies. Exposure comp is a combination of 1. shutter speed 2. aperture 3. ISO sensitivity One of those must change to increase your exposure. You can test this by putting the camera in any semi-auto setting. Let's use AV as an example. Say you have your AV set at f/5.6, to get the proper exposure through metering, the camera decides that with the current ISO the shutter speed of 1/250 will give you the proper exposure. If you increase the EV by 1 stop, you will notice that the shutter speed is now 1/125 (as long as you haven't changed the ISO) So the only way to maintain a desired shutter speed and aperture, you would have to increase the ISO (which we already suggested). Hope this helps. |
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There are some situations where a flash on the camera full firing just produces the best shot available. It's nice to have that available of needed. As others have said, higher ISO, faster lens (larger aperture), slower shutter speed (although with action shots that's pretty limited). Even a cheaper, older flash will give you much more versatility than the on camera flash. The church I shot a wedding at last weekend ad 40' tall ceilings, kinda hard to bounce off that. Poor lighting in the church as well, so, flash it was. Pics looked pretty good for the environment. Often just getting the shot is whats important. Good luck |
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I was actually reading a book on Flash Photography this weekend. The answer to your question can be calculated.
You said you were shooting a 3.5 to 5.6 lens at 1600 ISO. There is something called a guide number that helps you determine what distance you can get the right expose at a particular f/stop. Guide number depend upon the power of the flash. You have to check your particular unit's spec, but on Canon Speedlites the model number will tell you the guide number. For instance, I have a 420EX Speedlite flash. My guide number is 42 (420/10 on Canon products). That is in meters. Guide numbers are usually calculated @ 100 ISO. So if I have my lens at 3.5 f/stop the right distance for exposure would be 42m/3.5 = 12 meters or about 39 feet. So how do I calculate it for 1600. Well there is multiplier for the guide number for each jump in ISO and that is 1.44. So if I was shooting at ISO 200 I would multiply the guide number by 1.44 and then do my calculation. Here is a table to help you with that part. For a much better explanation than mine follow this image link back and read the article. 
So now I can calculate: max exposure distance = (42m * 4.3) / 3.5 (f/stop) that comes out to 51.6 meters or about 169 feet. If you were zoomed in all the way and shooting at 5.6 it would be (42m * 4.3) / 5.6 = 32.25 meters or about 106 feet The guide number on a Nikon D700 and D7000 onboard popup flash is about 11.8. So if you sub that into the equations above you get: 14.5 meters or 47.5 feet at 3.5 9 meters or 29.5 feet at 5.6 OK, so you're probably thinking that's not so bad, but there is more. Those numbers assume the subject is sitting still. If you are using a flash the max flash sync speed of the shutter (X-Sync) is typically 1/250 th of a second on a DSLR. It has to be faster than that to stop motion, and you have to figure out how to trick your camera into letting you get a faster sync speed. That's a topic I'm not qualified to discuss as I can barely get my hands around basic guide number usage. You may also run into depth of field (what is in focus) issues at those minimum f/stops. The bottom line is you will need a flash with a high guide number and a fast lens to accomplish what you want depending upon the natural lighting at the place. |
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Was your exposure comp maxed out as well? embarrassed to say i'm not sure i understand this question. p.s. aekdb gonna try jacking up the iso and see how that works. the lens is looking like the ultimate answer though but i need to experiment more. thanks for all the replies. AEKDB brother. Exposure comp on your Nikon can be changed by holding down the little plus minus button by your pic taking button and wheeling the little wheel left or right. I can usually milk a little more out of my kit lens with a combination of exposure compensation and setting the white balance manually according to the type of available light I have. As recommended in other posts, going a few more rungs on the F stop ladder will get you fantastically better results. |