Does a ikelite strobe work on a PT-23 housing, TTL ?

[rcolman]

From my answer to your other thread:

This piece turns the Olympus housing's proprietary bulkhead into 2 nikonos connections, and contains TTL conversion circuitry. I like the redundancy it adds over a Heinrichs connector-

Any strobe that can be connected elecrically, and is compatible with the Olympus TTL Conversion Circuitry, can be used. With the hotshe cable this part is $479.

Lastly, we can replace the existing proptrietary bulkhead with a nikonos style bulkhead & TTL conversion circuitry-

http://www.reefphoto.com/index.php?main_page=product_info&cPath=95_74&products_id=902

Either of those two options, combined with an Ikelite 4104.6 sync cord, would yield TTL. An ikelite housing w/ the OLY-TTL conversion circuitry is competively priced when this conversion is considered, and much more robust.

I have a warning on the Heinrichs converter. The one I bought, direct from Germany, is aluminum, and looks different from the one pictured on the reef photo advert.

Mine leaked externally where the Ikelite Nikonos-style cable connector attaches to the aluminum bulkhead. The cable connector has two spaced o-rings. The bulkhead only engages one of these two cables.

It was OK at 10' in a swimming pool. In the ocean, it flooded at 35'. I have sent the bulkhead back to Germany asking for a redesign or a refund.

contact me for more details.

Rick Colman
rcolman@cox.net

 

[kapula]

There's a very similar thread in flash dance forum. You could check it out. As Victor pointed out there are few options. One is to replace your bulkhead with Weikamps bulkhead, get an ikelite housing, buy a modified Weikamp adapter/cable from divervision (which is actually sold by divervision not uwdigitalcamera) or another modified Weikamp adapter/cable from uwdigitalcamera. Anyway go and take a peek at this thread. Hope it helped and if it did please let us know which way you leaned.

 

[slowhands]

The quick answer to TTL strobes on a PT-023 housing is to use the horrible Olympus underwater flash housing. It uses an underpowered FL-20 strobe in a special housing with cable to your camera housing. Unfortunately, the cable connector and housing bulkheads are made of dissimilar metals, which in salt water make a natural galvanic corrosion site (in other words, the cord welds to the housing). Not recommended. On many of these housings the bulkhead is broken off when you try to remove the plug. Strobe only has enough power for macro work.

So, Heirrichs Weikamp made a better widget for the later Olympus C series housings (PT-020, -023 and -027). They replace the Olympus bulkhead connector with one that connects to Nikonos interface strobes, like Sea & Sea etc. Inside the housing, you place an adapter in the strobe hotshoe, which connects to the new bulkhead. The adapter does the magic to convert Olympus strobe control signals to Nikonos signals. Not cheap, but works with many existing Nikonos style strobes. I use a YS-90DX with it.

For a new purchase, Ikelite housing may be a cheaper way to go when you total up the cost of everything needed. It certainly has better support, but is likely to be discontinued soon, since the 8080 is discontinued already.

And you will appreciate the modeling light on an Ikelite DS-125 to help your 8080 focus in low light. It will hunt for focus a long time without that.

 

[Life-Is-Good-Diver]

The quick answer to TTL strobes on a PT-023 housing is to use the horrible Olympus underwater flash housing. It uses an underpowered FL-20 strobe in a special housing with cable to your camera housing. Unfortunately, the cable connector and housing bulkheads are made of dissimilar metals, which in salt water make a natural galvanic corrosion site (in other words, the cord welds to the housing). Not recommended. On many of these housings the bulkhead is broken off when you try to remove the plug. Strobe only has enough power for macro work.

So, Heirrichs Weikamp made a better widget for the later Olympus C series housings (PT-020, -023 and -027). They replace the Olympus bulkhead connector with one that connects to Nikonos interface strobes, like Sea & Sea etc. Inside the housing, you place an adapter in the strobe hotshoe, which connects to the new bulkhead. The adapter does the magic to convert Olympus strobe control signals to Nikonos signals. Not cheap, but works with many existing Nikonos style strobes. I use a YS-90DX with it.

For a new purchase, Ikelite housing may be a cheaper way to go when you total up the cost of everything needed. It certainly has better support, but is likely to be discontinued soon, since the 8080 is discontinued already.

And you will appreciate the modeling light on an Ikelite DS-125 to help your 8080 focus in low light. It will hunt for focus a long time without that.

Thanks for all the info!!

I'm using the DS-125 with the EV Manual controller, with the 10 manual settings.

I just back from a trip, and only got to dive one afternoon, but I way over exposed every shot.

I pointed the stobe away, lowered the strobe output to 1/8th and 1/4 , but still way to much light.

I'm thinking of just going with a Ikelite housing, and selling the Pt-23 set up, and using the true TTL, so I dont have to manualley keep adjusting the output of the stobe

 

[bobf]

..........
I pointed the stobe away, lowered the strobe output to 1/8th and 1/4 , but still way to much light.................

When using the 10 step EV controller to limit the strobe's output, I believe the correct setting on the DS 125 is to aim the dial to TTL.

Also, what mode was the camera in? Program, Shutter Priority, Aperture Priority, or full Manual? And finally, what was your ISO setting? Fixed or Auto?

 

[Life-Is-Good-Diver]

When using the 10 step EV controller to limit the strobe's output, I believe the correct setting on the DS 125 is to aim the dial to TTL.

Also, what mode was the camera in? Program, Shutter Priority, Aperture Priority, or full Manual? And finally, what was your ISO setting? Fixed or Auto?

I shoot in P mode, Program mode , ISO is 100 , auto focus , does that help

 

[bobf]

I shoot in P mode, Program mode , ISO is 100 , auto focus , does that help

Without seeing the images my guess is that in "P" mode, the camera is choosing a relatively wide aperture to address what it perceives as a low light situation underwater.

Let's assume for example that the camera chose f/2.8.

For the sake of this example, let's also assume you were 3 feet from your target.

We now have two known factors of the Guide Number equation, aperture and distance. In theory we can now compute what the proper intensity level for strobe light should have been to achieve an acceptable exposure. The Guide Number equation is:

GN=A*D

or, Guide Number equals Aperture times Distance.

Aperture set by the camera in "P" mode we assume to be 2.8. Distance for this example is 3 feet. Multiply 2.8 times 3 to find out how intense (guide number) the strobe influence should be. 2.8 times 3 equals 8.4. Our target GN is 8.4.

Let's change gears now and figure out what the corresponding Guide Numbers are to the optional intensity levels available on a DS 125.

At ISO 100, a DS 125 GN at full power is 32 (feet, not meters).
at half power (divide by 1.4) the GN is 22
at quarter power (divide again by 1.4) the GN is 16
at eighth power, the GN is 11.

So, if your target was three feet away, and you chose an aperture of f/2.8, then in theory you should have been overexposing the foreground of your image.........by about one stop of light........even at 1/8th power.

If you were even closer than three feet........you would surely have been overexposing the foreground if indeed the camera was choosing f/2.8.

There are ways to minimize the intensity of the DS 125 even further. Adding the diffuser will lower the GN at full power by one stop, or an equivalent of GN 22 (ISO 100, Feet). Setting the ISO to lower than 100 (some digicams allow ISO 64 as an example) is another.

What is still unclear to me though is if you were setting the strobe by the levels found on the strobe itself (F, 1/2, 1/4, 1/8) or were using the 10 step EV controller (F, 0.5, 1, 1.5, etc)?

hth,
b

 

[Life-Is-Good-Diver]

All of my shooting is withem 3' , I dive shallow reefs when bringing the camera, and whats happening is everything is coming out white, from way to much strobe light.

I shot the strobe on 1/8th power, diffuser, and manual Ev controller set to 4.5

I even tried alot of positions with the strobe, pointing it away from the subject, and trying to catch the subject in the outta premiters of the strobe light.

Sounds like I'm over powered ?

Maybe go with the DS-50 like I had before ?

with the Ds-50 , It wasnt as much light output , I think it was 50 watts if I remember, and the DS-125 is 125 watts.

The manual said to set the strobe output to F, meaning full power, and adjust the EV controller, and adjust for 1 full stop for the diffuser.

It's not making sense though, because the Ev controller is set to 4.5 , which is the lowest setting, and the strobe set to 1/8th power, which is less then 30 watts, and I'm still overexpossing the background with to much light.

I live in Florida, and dive ALOT in the Keys, where reefs are generalley 25'

My friend is sellign a Canon DSLR set up, and takes beautifull pics with full TTL.

I was thinking of buying his set up. I don't like all these manual settings with the Olympus housing's. By the time I spend another $250 changing the bulk head, i could have just bought a Ikelite housing

 

[Life-Is-Good-Diver]

Bob, if you send me your email, I could send you a few pics, I appreciate all your help, cause I'm fustrated with this set up all ready, and i just got it , lol

 

[AUTiger]

With my C-5060, which is similar to the 8080, I followed the settings on this page:

http://www.splashdowndivers.com/photo_gallery/underwater_photography/up_settings.htm

They got me off to a good start. I agreed that f/5 and 1/100 is a pretty good starting point. I used a DS-125 with a slave sensor and the Oly housing for a year.

As I think was mentioned, look at the exif data for your picturs and see what the shutter speeds and aperatures were. Compare them to f/5 and 1/100. If the f stop is smaller, then the picture will more exposed (eventually being overexposed as you get too wide). If the shutter speed is faster, then the backgrounds (non-flash zone) will be darker and they will lighten up as the shutter speed decreases.

David