So, I was home by myself again and I thought "hmmm, I should really have another crack at the waterdrop pictures."
I was given a simple physics lesson by this astute 14-year old. Yup, to get a nice big splash you need kinetic energy, Ekin, which happens to equal (mv^2)/2. Now I don't have much control over the mass of the water drops m, but I do have control over it's velocity or more precisely the distance over which the drop accelerates due to gravity! ie v2^2 = v1^2 + 2gd (where g is the gravitational constant 9.8m/s^2 and d is the distance between the shower head and the bowl, v1 is initially zero). Duh!
All this was simply put by my 14 year old acquaintance as
"The kitchen sink is too small :( try the shower!"
So I did! And I think the results have speak for themselves compared to the 1st lot. I think the biggest achievement was switching the SB-800 into repeating mode for just a single cycle at 100Hz. This mean the shortest flash duration in one blast lasting 1/100th of a second!
I think I've coming up to the limits of what I can do with the equipment I have. The next stage after this, is a laser or audio trigger for the shutter and strobe. I don't think the SB-800 was meant to do more than this, anything more than this definitely requires some specialised equipment.
I've played around with the white balance on the computer to make the drops look a little more interesting
I also tried a few with a coloured gel on the flash for some alternative colourings
The rest of them are on my Picasa webalbum here. I'm thinking of printing out a few, maybe you could suggest which ones are most appealing for you!
Whilst you are bumming around websurfing check out this dood's page, Liquid Sculptures, it's amazing what you can do with the right equipment!
Original waterdrops here
2 comments:
That last one is awesomo
They're all pretty damn good and heaps better than before.
I might hafta have a stab at this since now I own a decent set of legs.
"I think the biggest achievement was switching the SB-800 into repeating mode for just a single cycle at 100Hz. This mean the shortest flash duration in one blast lasting 1/100th of a second!"
Are you sure.. I was under the impression that that just meant the frequency of flashes was 100 times per second, but the actual duration of the flash depends on the output strength (or vice versa..). Maximum strobe duration of the Sb800 at full strength = 1/1050 second, at minimum strength it's 1/41600 sec(that's what the manual says)
I wouldn't think a flash duration of 1/100th of a second would be fast enough to freeze that sort of motion.
Anway, it's all academic as you got the shots :P
Yep I think you are right, I did a quick calc on how far a water drop moves in 1/100 of a second, give it's acceleration over the distance from the showerhead and it came out to about 5mm in 1/100th of a second. So the flash much be discharging in a much shorter time than 1/100th of sec, but it seems to be the only way to drop the motion blur short of using 1/8000 shutter speed. Have a play and tell me what you find out. You might want to use a teleconvertor on the 90mm to give you a bit more stand off from the splashes. I had to wipe down the camera and lens afterwards. Good thing for the body seals (take that canon 5D!)
Post a Comment