HID light vs. Strobe

[Neopreneninja 0]

What's the best source of UW light ??

I'm a Newbie thinking of buying UW-light..as I see it The UW-light system from "Geen Force" with a 25W HID constant light..focus light and instant exp. with the HID..but do's it scare the fish away!!?? seems a better option than a didecatede strobe like the INON 2000 etc. as it will function as a light for a night dive as well...where as a strobe is nothing but a strobe..

wich has the best light for fill in ans night dive photo's ???? con's and pro's ????

any one have any comments..I know it's slightly more expencive for the HID...I'm looking at buying a system that can grow with my canging cameras...

Plus it seems like most of the Pro.'s stick to Strobe...

Please help

[acroporas 0]

The reason that people use strobes is that they are MUCH brighter.

 

For example, lets assume a shutter speed of 1/50th of a second. So that 25W HID light has put out 25 watts for 1/50 second or 25W x 1/50s = 0.5 watt seconds.

 

Compair that to a small strobe like the Ikelite DS-51 strobe (i'm using Ikelite as an example because that is the system I know) It puts out 50 watt seconds. So even a small strobe like the DS-51 is 100X brighter....

 

Also, many of the nicer strobes have built in modeling lights that doubble as a flashlight for night dives....

[uw_nikon 0]

Get a strobe and a separate focus light.

 

Why _not_ HID?

-even though HID lights are bright, they don't put out as much light as a strobe does.

-a strobe can stop action (HID cannot)

-a strobe has many power settings (HID one setting)

 

Why separate focusing light?

-in underwater photographic lighting, you almost _never_ want the strobe pointed directly at your subject (edge lighting doesn't illuminate the water between your lens and the subject; less backscatter. With a focus light built-in to your strobe, you have to point the strobe at the subject to focus.)

-you don't need a huge/super bright light for a focus light _or_ night diving (most of the time you're trying to light a subject that's no more than 4' (1.2m) away from you light (and yes bright focus lights do spook subjects night or day)

 

Other things to consider:

-diffusers cut the power of your strobes and make the shadows softer

-eventually, you'll want a second strobe to fill in those harsh shadows (matched pairs are best for lighting flexibility)

-get a good strobe arm and tray to start (it will save you lots of headaches)

 

Take Care,

ChrisS

[drsteve 6]

Another consideration is that a really bright HID will scare the fish away. Since the strobe only puts out light when you take the image, it doesn't impact behavior, until the image is taken. That being said, you need to be cognizant of the fact that too much strobe can temporarily blind the fish, just like people.

[craig 0]

...and if all those reasons aren't enough, strobes offer a far better spectrum than HID. HID lamps have CRIs of 75-80 whereas strobes will be in the 90s. Anything below 90, some say 95, is not acceptable for critical photography work. That's why cinematographers use special HID lamps, otherwise known as HMI, to get the CRIs into the 90s. For a still photographer it would be pointless to accept such limiting equipment much less pay extra for it.

 

One of the joys of still photography is that you get to use strobes.

[Neopreneninja 0]

Thanks Guys!

As A Newbie there is lots to lerne...and I've been reading a lot of books, articels and other input..some of whom mentioned this HID light and when I discovered that Green Force made a UW-P&S photo kit..then I thought well why not !

It might be a 50W HID but I get the point..strobs are King ! for my part I saw the benefit of having constant light..what you see is what you get exp. wise..! (just a Newbie thourgth)

Great Forum and super fast respons one even the dumbest Newbie questions....THANKS AGAIN GUYS!!!