Why is a direct hotshoe connection better than the fiber optic cable???

Why is a direct hotshoe connection better than the fiber optic cable???

I have been using a fibre optic cable to connect my auto strobe to the camera. As I know(please correct me) the strobe will calculate the proper light intensity for the shot. The camera will tell the strobe when to fire. What does the direct connection of a hot shoe gain in the shot?

The Hotshoe will have better communication in ttl? What does this really offer? The hotshoe will also help stop miss firings, but creates another leak point.

thanks.

There are many ways to get the right amount of light on your subject. One way is to control the strobe manually, another is to let the camera control the strobe (TTL), another is to let the strobe control itself (AUTO strobe). Only common thread is that the strobe needs the camera to tell it when to turn on. The two ways (that I know of) for a camera to tell a strobe when to turn on are 1) to signal electrically, and 2) to use its own internal flash to signal the strobe to fire (in effect, the external strobe is a slave of the master in the camera). It used to be that there wasn't a good way to use the camera's internal flash to trigger strobes (many old DSLRs, and many "professional" ones now, had no internal flash at all). With the availability and expanded use of fiber optic cables, the expanded use of cameras with internal flashes underwater, and the development of more specialized slave strobes with recycle timnes fast enough to replicate preflashes, it has become much easier to ensure a slave strobe gets the right signal from the camera, making fiber very reliable. In general, the only real downside of using fiber cables to trigger the strobe is that you have to use the camera's internal flash to trigger it. This potentially has negative impacts on battery life and, possible, on the internal temperature of the housing. The temperature issue is probably not a big deal, unless the housing is very low volume, but I mention it because others have listed it as a concern before. The upside to the fiber connection is that you don't have to worry about flooding am electrical synch port (or possible flooding a whole housing through one (depends on housing design)). In addition, if the strobe can handle the pre-flash replication necessary to match a number of cameras, you don't have to have specialized circuitry to convert a particular camera's electrical TTL signal for a given strobe. I use fiber cables to connect my Seatool Canon 40D housing to INON strobes and find the combination to be very good. I've not run into issues with the camera battery being drained excessively by using the camera's flash and the I've found the TTL replication to be quite nice.

Mike

thanks, I was thinking of when I buy my next strobe and case and was wondering if it was worth to get a case with a ttl for my camera. I guess I can save the $400 and get a better strobe than a better case.

I can only think of one absolute advantage of an electrical connection, which is the absence of stray light bouncing into the lens reflected from the internal strobe.

Electrical connectors eventually leak - although this only happened to me once.

I prefer fibre-optic connection, but do use a housing and strobes that are specifically designed for this function.

Nexus, D200, Inon Z240 strobes, dual fibre-optic connectors.

Tim

Interesting, I didn't know that there were DSLR housings that had fiber-syncports.

thinking about heat and batterydrain, it would be vesy simple to create a hot-shoe device that mimics a TTL flash and just sends out a light signal (using LED of example) where the fiberoptic connects to the housing, thus consuming less power. (or some something similar already exist?)

Interesting, I didn't know that there were DSLR housings that had fiber-syncports.

 

 

thinking about heat and batterydrain, it would be vesy simple to create a hot-shoe device that mimics a TTL flash and just sends out a light signal (using LED of example) where the fiberoptic connects to the housing, thus consuming less power. (or some something similar already exist?)

I was thinking exactly the same, except my version of a wireless hot shoe would connect to the hot shoe, wireless through bluetooth, RF, or IRDA to outside the case and then connected directly to a manual strobe.

I can not see ikelite or some others making this since it will take away business from their underwater case sales.

Interesting, I didn't know that there were DSLR housings that had fiber-syncports.

 

 

thinking about heat and batterydrain, it would be vesy simple to create a hot-shoe device that mimics a TTL flash and just sends out a light signal (using LED of example) where the fiberoptic connects to the housing, thus consuming less power. (or some something similar already exist?)

INON built one for certain cameras:

http://www.inonamerica.com/products.php?pr...=4&subcat=1

Mike

I converted my Subal C40 housing to fibre optic earlier this year using a conversion kit from Reef Photo & Video. The major advantages that I gained were the ability to shoot using TTL using Inon's excellent sTTL system and being able to shoot using second curtain sync.

can only think of one absolute advantage of an electrical connection, which is the absence of stray light bouncing into the lens reflected from the internal strobe

Heat and battery drain have not been an issue since converting.

INON built one for certain cameras:

 

http://www.inonamerica.com/products.php?pr...=4&subcat=1

This deivce seems to connect on the outside of the housing?

I was thinking exactly the same, except my version of a wireless hot shoe would connect to the hot shoe, wireless through bluetooth, RF, or IRDA to outside the case and then connected directly to a manual strobe.

 

I can not see ikelite or some others making this since it will take away business from their underwater case sales.

Maybe we should design such a device... maybe if I find the time to investigate into TTL electronics I'll try to get something going.

Fibre optics win on so many levels, but there are lots of strobes that you can't fire with them. The tie you to using certain brands of strobes.

Alex

you can cheat a little if you're using an ikelite housing.

i use a 350D in an ikelite, and there's just enough space for the pop-up flash to work. i just tape on the FO cords in front of the housing, and I get the option to use both my ikelite strobes or inons.

now, if only canon would make a 5D with a built-in flash...

<snip>

thinking about heat and batterydrain, it would be vesy simple to create a hot-shoe device that mimics a TTL flash and just sends out a light signal (using LED of example) where the fiberoptic connects to the housing, thus consuming less power. (or some something similar already exist?)

I asked Matthias Heinrichs about this about a year ago and he was pretty convinced it would be almost impossible, at least with leds. IIRC his argument was along the lines that LEDs are too slow to fire & quench in comparison to the different TTL's to make them a viable solution.

INON built one for certain cameras:

 

http://www.inonamerica.com/products.php?pr...=4&subcat=1

 

Mike

It's close, but it still goes connected to a camera via a bulkhead. From the Inon connector out it is a fiber optic connection to the strobe, but in the end you still need a bulkhead.

I was thinking exactly the same, except my version of a wireless hot shoe would connect to the hot shoe, wireless through bluetooth, RF, or IRDA to outside the case and then connected directly to a manual strobe.

 

I can not see ikelite or some others making this since it will take away business from their underwater case sales.

I can see IR maybe working (after all, I 've heard several times that in P&S cameras the best way to go is to block off the camera's internal flash with exposed film to keep visible light from penetrating and letting the IR trigger the strobe), but I doubt RF would (unless you were to build a reciever that goes on the outside of the housing or use RF strobes). But then I don't know as I'm just a beach bum biologist.

This deivce seems to connect on the outside of the housing?

 

 

 

Maybe we should design such a device... maybe if I find the time to investigate into TTL electronics I'll try to get something going.

Yes, it connects to a bulkhead outside the housing and converts the electrical signal from the camera's hotshoe to an optical one that gets transmitted via FO cable to optically triggered strobes (in particular, Inon's). The way I see it, is you still have the bulkhead weakpoint for flooding, You just eliminate the need for a synch cable by replacing it with a FO one (which are cheaper to fix/replace if the cable floods).

It would be awesome to have such a device! I am buying a Fantasea housing for my P5000 and was just sending Matthias an email asking about putting one of his bulkheads & iTTL converters in it, but I'd much rather go with a solution like this since I wouldn't have to drill a hole through the housing. While I'm at it, I'll ask him to jump in here.