Help Olympus Stylus 790/PT-041. Strobe?

[Bob Vincent]

Ok people ... help! For X-Mass I received a Olympus Stylus 790SW ( the waterproof to 10ft model ) and an Olympus PT-041 housing. ( I hope this housing holds back water over or around 110-120 ft mark its rated for 40m/133ft.)

1. with no strobe how does the built in flash due?
2. how about the Olympus underwater strobe designed for this style of digital, anyone?
3. if not the Olympus strobe, which one?
4. well ... what do I need to know?

Haven't really took pictures underwater since I sold my Nikonos-V/SB105 except for the really really really cheap cameras in housings that flood at 100ft.

All help will be appreciated.

 

[Nemrod]

Let me try to explain what I know and then your free to do as you please. The Olympus P&S cameras like the 790SW and 99% of all non SLR digi-snaps use a preflash/flash system. What this means is that when the camera determines that flash is needed and the shutter is pushed the camera emits a small PREFLASH and that is rapidly followed by the main flash. This preflash allows the camera to calculate correct exposure and flash requirements. P&S cameras do this in lieu of true TTL sensing. The power of the main exposure flash is therefore related to the conditions the camera senses from the preflash. This happens with every flash cycle (so fast you see only one flash) unless you have the flash selected OFF. In order for an acessory strobe to work it must be capable of resisting the urge to cycle with the preflash and wait for the main flash when the shutter is actually open for starters.

The more sophisticated strobes go further, they emit a more powerful preflash in conjunction with the cameras preflash--this tricks the camera's flash/exposure computer and makes it think it does not need a strong flash and this reduces the power output of the camera's strobe saving battery power and reducing heat build up in the housing which causes condensation. Inon goes further yet, they have developed a system (called Clear Photo System) which uses small adhesive film to cover the camera flash stopping all light but infrared. The strobe optic cable still sees the infrared output and that is what fires the Inon D2000 strobe. Because the flash is fully supressed by the combination of film and strobe preflash FLASH CANCEL illumination of particals in the water is greatly reduced because now the only light that is reaching the subject is off axis to the lens. I hope that this explanation is helpful. Test firing the Inon D2000 with the "Clear Photo System" film in place proves to me that I believe the system works, the camera's flash is completely subdued and all of the subject illumination comes from the D2000 including the preflash for setting the cameras exposure/flash requirments--all AUTOMATCALLY. This is the best I understand it. And that is quite a trick with no hard connection!

Strobes generally are not of much use beyond four or five feet so I doubt the built in strobe will reach that far thus the need for wide lenses and wide angle strobes. the built in strobe will most likely cause heat and condensation in the housing.

Adios, good luck.

N

 

[Bob Vincent]

Thanks ... I'm in for a huge learning curve. I never would of thought about the heat built up and condensation it causes. No wonder the moisture packets! And I didn't understand about the pre flash and main flash, I knew about the red eye lol. At least you gave me a few things to look for and not to look for. Just call me digital dulard!

 

[diverdowndh]

I have an Olympus D600 with the PT-029 housing. I've had it to over 100 feet deep with no problems. I added a SeaLife strobe which triggers from the preflash. I'm really happy with it. It is light, not really big and the strobe made some of my shots come alive. The Sealife strobe has a battery pack that I'm not very fond of, it seems sort of cheap. It comes with several switch settings to work properly with other cameras (non-Sealife) and after a couple of dives I have it working well. It didn't cost much and the benefit for me was good, so I recommend looking into it. Oh yeah, there is supposed to be a newer version out that checks turbidity of the water and makes some on-the-fly adjustments for you that help with pics, but I have not heard of anyone who has one. Hope it helps!

 

[Bob Vincent]

diverdowndh which Sealife strobe? Is there more than one model? What model number do you have.

Thanks bunches!

 

[ScubaBasics]

Sealife has a new digital strobe being released at Our World Underwater. On more option would be the AF-35 Strope pkg. from Ikelite. IKELITE AutoFlash Kit AF-35 Specifications

 

[Mark Rupert]

Inon is another choice.
Ref: PT-041 set-up.
Kind of on the expensive side - but you get a lot of performance and reliability.
-Mark/Inon America

 

[Mark Rupert]

Ignore mistaken link above.
This one is right.
PT-041 set-up

 

[diverdowndh]

Here is the one I have:
Accessories | External Flash

From what I heard the newer version of this measures tubidity of the water and does some adjusting for you. The only thing I do not like about this is the 4 AA battery pack is kindof cheap, but I also heard the newer version addressed that problem too. Sometimes the flash just wouldn't go off and if I smack it then it will <grin>. The good news is that I love it. It has brightened up my pics tremendously (of course) and it is light, easy to carry or work with, and kept me from having to purchase a whole new photography setup... which would have been expensive.
D

 

[Bob Vincent]

Guys ....... Thank You Thank You Thank you! Scubabasics I'm going to have to take a look at Ike again ... I'm going to have to get a new catalog. Mark thanks for the Ion the wide angle is way cool ... more to look into. Diverdowndh the Sea Life stuff I'm going to read up on.

I'd still like to know if anyone is using the Olympus Strobe?

I'd love to compare price vs power between a few.

Again much thanks!