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 OctoPort - bulb splitter for up to 8 cameras 
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Post OctoPort - bulb splitter for up to 8 cameras
People occasionally ask me if Little Bramper can be used to execute accurate bulb exposures on more than one camera. The answer is no, primarily because the shutter on each camera must be monitored separately. OctoPort represents a simple solution to this problem. At its simplest, you just feed it a single input signal and it reproduces that at up to eight camera outputs (each of which is optocoupled). Pretty much what you'd expect from a camera splitter to do.

OctoPort also has a special Bulb mode for use with Little Bramper - each camera now requires a PC connection to permit shutter monitoring. In this way it can precisely relay a Bulb exposure to each camera. Since each camera is controlled separately you can use a mixture of camera models. In Bulb mode OctoPort computes a running average of the shutter lag of each cameras, introducing a compensatory `stagger' so that, in an average sense, the shutters all open at the same time. Similarly, other parameters are monitored. To switch between Basic and Bulb modes you just press a button, everything else is automated. Also, it has some attractive multi-coloured status LEDs and the battery holder is secured to the rear of the circuit board.

If you have any Qs or want to see a particular function implemented, please speak up.

I'll be making 50-60 units. I'm still debugging the firmware (yes, it requires a microcontroller) but if you'd like to be notified when they're available drop me an email with "OctoPort" in the subject line, at littlebramper at gmail.com. As you may know, Shutterdrone is also making a splitter, so you'll actually have a choice.

Here's a prototype (note: final version will look a little different),

Image

A couple of pictures with input devices

Image

http://www.thewhippersnapper.com/OctoPort

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Thu Aug 11, 2011 8:07 am
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Post Re: OctoPort - bulb splitter for up to 8 cameras
astronomerroyal, good afternoon.

Shouldn't there be 2 connectors to do ISO ramping with the LBR?

Suggestion: Add a couple holes for mounting or hanging the unit, maybe even have them line up with the LBR holes that are for the LCD screen... There should be enough of us using both that we'd want them mounted as a whole single unit.

Besides, I don't want to have to take my Milwakee to the thing right off. :-)

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Thu Aug 11, 2011 11:39 am
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Post Re: OctoPort - bulb splitter for up to 8 cameras
AR: Care to suggest a source for 12-24" PC to 3.5 or 2.5mm cables?

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Thu Aug 11, 2011 2:08 pm
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Post Re: OctoPort - bulb splitter for up to 8 cameras
BerthaDUniverse wrote:
astronomerroyal, good afternoon.

Shouldn't there be 2 connectors to do ISO ramping with the LBR?

Suggestion: Add a couple holes for mounting or hanging the unit, maybe even have them line up with the LBR holes that are for the LCD screen... There should be enough of us using both that we'd want them mounted as a whole single unit.



A second interconnecting cable is not required - presumably you're talking about the lack of PC cable. What I did forget in the above photo is to plug the little terminator plug into the PC jack on the Little Bramper. I'll need to retake the photos for the user manual. In this setup Little Bramper doesn't need to see any of the camera shutters, it merely needs to convey an exposure of T milliseconds. For this purpose the terminator plug will suffice as a `dummy shutter signal'. OctoPort then does the business of properly exposing each camera for that duration. One must ensure that Little Brmper is triggering for the time sated on the LCD screen, and to accomplish this one merely sets the XTime to 0ms.

I was going to add some holes but hadn't thought about mating it with Little Bramper. A very good idea, although there's actually a battery pack affixed to the underside of OctoPort, making the business a bit difficult.

For the 12" PC to 3.5mm cables, I recommend ebay. I got my contact via an ebay seller. I tend to go for the 'Ask a question' button and request a custom wholesale quote.
http://cgi.ebay.com/3-5mm-Plug-Male-Fla ... 33602c0df9

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Tue Aug 16, 2011 7:30 pm
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Joined: Thu Jul 22, 2010 5:29 am
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Post Re: OctoPort - bulb splitter for up to 8 cameras
Astronomerroyal: Thanks for the cable info.

Yea, I was asking about the PC control cable. Thanks for the details.

Any chance of a common power source or a unified/unifying cable that will power both at the same time? The LBR dosnt seem to drain very quickly, or how about an 8 cell pack. The fewer of those 4 AA battery packs floating around the better.

I personally would prefer to have the battery pack for the two parts "common" and the ability to have them remote, as the battery weight is the one thing the can cause the cables to be pulled out.

BTW: Hope I made the list... ;-)
Pb

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Tue Aug 16, 2011 9:44 pm
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Post Re: OctoPort - bulb splitter for up to 8 cameras
I'd love to see someone iso ramping 8 cameras at once! You would need to be an octopus! Ha ha.


Tue Sep 13, 2011 4:25 am
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