Optical synchronization ... Big question ?

[Larry C]

I may be off base on this, but in my experience with an optical strobe, if your camera has a preflash and adjusts for the internal flash in auto modes, you can set the strobe on normal, and allow it to flash with the preflash. As long as it has time to recycle before the main flash (mine wouldn't on higher power settings, but would on the minimum power I usually keep it at) it will flash together with the strobe and I haven't had overexposure problems in auto mode while doing this. I know zip about how the camera's auto mode adjusts to the built in flash or strobe, but it worked for me.

 

[RonFrank]

I think a LOT of generalizations abound about how things like iTTL, eTTL, optical slave sensors, and flash technology work. What people need to understand is that this is all based on how each manufacture has engineered a solution, and that is likely not even narrow enough. Name the flash make and model, and then MAYBE we can begin to discuss if it works well in mode X. Since not ONE of us are working on these designs, and they are closely guarded by first the OEM, and then by the third party manufactures like Ike and Inon, I would not expect that any of us has an exact understand of what goes on behind the covers.

Case in point the Inon D2000 uses the camera's preflash to determine the proper flash exposure. Preflash has meaning. In fact preflash is communication in many camera's. Nikon uses their preflash to communicate the camera's exposure settings, subject distance, and other information to control remote wireless flashes.

Inon has come up with a way they think works well with the D2000 to use the preflash as an exposure reference to control their flash. Does this work well? I don't know as I don't own that flash, but obviously Larry C who owns this system feels it does.

HERE is a link that leads to an explanation of Inon STTL technology, and they seem damn proud of it, so my bet, it works better than people may expect!

I think one statement that is generally true is that if in doubt, set the strobe using a manual method and use experience, and a histogram to judge if that is producing the desired output! However just like we rely on TTL exposure to determine our camera setting if that be manual, Aperture, Shutter whatever, flash manufactures are going to continue to engineer solutions so we will have the same confidence when using a flash. Topside it is already a reality, but UW strobe manufactures are a bit behind, but catching up quickly.

 

[Peter Guy]

Having used the Inon D2000 on my recent trip to Indonesia all I can say is I think it worked very well! I set the strobe on sTTL and generally used either shutter or aperture priority on my Canon S80. I did NOT set the WB manually because almost all of my pictures were using the strobe. (And of course I don't have the RAW option, sigh.)

Here is one sample -- you can decide if the optical synch worked:

 

[Yasser]

Wow .. that's a great shot.
Was that with TTL sync between camera and strobe ? or only optical sync without TTL ?

 

[RonFrank]

Wow .. that's a great shot.
Was that with TTL sync between camera and strobe ? or only optical sync without TTL ?

He said the shot was doing using sTTL, which is Inon's way of using the camera's through the lens metering system, and the preflash to control the external strobe. Looks like it works rather well from this one example!

 

[Yasser]

Thank Ron for the input ....
We all agree that TTL sync is the best.

What we are questioning is using optical sync to fire the stobe in digital cameras.
Still we are saying that optical sync without TTL is like try and error execise.

 

[alcina]

Actually, I'm not saying ttl is the best. I think manual is the best option and ttl is a tool that can be effective in some situations.

Fibre optic cords work just fine. I have not noticed any difference between using them and using a hard wired strobe.

 

[RonFrank]

Actually, I'm not saying ttl is the best. I think manual is the best option and ttl is a tool that can be effective in some situations.

I have the opposite view, flash TTL is the best, and manual is a tool that can be effective in some situations for photo journalistic applications! Actually both work very well, but in flash TTL mode one adjusts the flash by adjusting the aperture on camera rather than a multi step process of adjusting the camera, than one or two flashes. In addition subject distance also adjusts the flash output just based on focusing.

I have a good track record in predicting if technology will become *standard*. So far I've argued pro in camera meters, 35mm for wedding candids, AF, LCD's on camera's (vs. analog only), and the most recently... digital. Ironically their is always huge resistance to each step. In the long run over time people forget that there ever was a debate. I mean who would argue that AF can not do a better job than MF for most applications? Try manually follow focusing a bird in flight, and make that argument.

I have a unique perspective in this because while I generally am making arguments for technology, I also tend to continue to own and shoot using old school methods for many things. I was using hand held meters, manual focus, and medium format film with monolights up until this spring. I still have and use everything BUT film.

Flash TTL is easy to predict, it's already the standard topside for journalistic applications! Not so much for studio lighting, but that's a very different application. Why would anyone want to fuss with controls on a flash when they can just shoot? Granted many situations will need some fine tuning, but eTTL/iTTL makes that easier as well.