[Fototim]

The question have probably been asked before, but I haven't been able to find any useful information.

What are the options if you want to use HSS and off camera flashes?
I don't think the existing IR system is an option for me, because IR tends to fail when HSS is needed.

[JimJohnson]

The question have probably been asked before, but I haven't been able to find any useful information.

What are the options if you want to use HSS and off camera flashes?
I don't think the existing IR system is an option for me, because IR tends to fail when HSS is needed.

You can do off-camera wireless HSS, but you have to have the right pair of flashes to get the job done. The built-in flash does not support HSS. Both external flashes would have to support HSS, and support P-TTL wireless master and slave modes. That creates an elite group of options. Your other choice would be to use a HSS capable flash and a wired connection that supported P-TTL between the hotshoe and the off-camera flash.

[Fototim]

Hm. Are you saying that I need to use a P-TTL compatible flash as master and another P-TTL flash as slave? That hoovers.
Does this mean that I can't use HSS i manual mode?

Please tell me that this is incorrect.

[JimJohnson]

Hm. Are you saying that I need to use a P-TTL compatible flash as master and another P-TTL flash as slave? That hoovers.
Does this mean that I can't use HSS i manual mode?

Please tell me that this is incorrect.

So sorry, you got it correct. High Speed Sync requires the flash to strobe as the focal plane shutter moves across the sensor gate as a slit narrower than the gate itself. The timing of these multiple flashes is as you can imagine, rather critical, and P-TTL provides the timing. Even if you do it with a wired off camera flash rather than wirelessly, you still need P-TTL to control the timing.

There are multiple threads here describing how HSS works so I am not going to repeat all that. Bottom line, no manual HSS - it simply isn't possible.

I don't know your intended use, but given how HSS works, its best use is for fill flash in bright ambient lighting conditions. Contrary to what a lot of people might think, it is really not appropriate for freezing action.

[Fototim]

I know the basics on how HSS works. It makes many small (short) bursts of light, instead of one biggie. And that makes HSS unsuited for action. It simply isn't enough light to overpower the ambient light.

The reason for my scepticism on TTL is that it's not predictable enough. Therefore I prefer to do all flash work in manual.

Thanks anyway sir :-)

[JimJohnson]

I know the basics on how HSS works. It makes many small (short) bursts of light, instead of one biggie. And that makes HSS unsuited for action. It simply isn't enough light to overpower the ambient light.

The reason for my scepticism on TTL is that it's not predictable enough. Therefore I prefer to do all flash work in manual.

Thanks anyway sir :-)

I use P-TTL, and I own one flash capable of HSS (and I think wireless HSS capable). I have never bothered with HSS for the reasons you give. The operational range with HSS tends to be short.

[Class A]

What are the options if you want to use HSS and off camera flashes?
I don't think the existing IR system is an option for me, because IR tends to fail when HSS is needed.

You may want to check out the Aokatec triggers.

They convert the optical wireless signals from the camera or on-camera flash to radio signals and then convert those back to optical signals at the off-camera flash end.

I find them to be too kludgy to consider them for myself, but they are the only option I'm aware of that could address your case.

[maxfield_photo]

You can also use a TTL cord if you only have one flash. I use this one FlashZebra.com: Off Camera TTL Cord for Pentax — 3 Foot Coiled Cord (Item #0237) Unfortunately, it's a little shorter than I'd like, but I'm considering buying one of the Nikon 24 foot TTL cords, then soldering the Nikon wire to the Pentax shoe mount. Someone else suggested an RJ45 network cable might work.


[Edit: here we go]

Youtu.be

Youtu.be

[JimJohnson]

You can also use a TTL cord if you only have one flash. I use this one FlashZebra.com: Off Camera TTL Cord for Pentax — 3 Foot Coiled Cord (Item #0237) Unfortunately, it's a little shorter than I'd like, but I'm considering buying one of the Nikon 24 foot TTL cords, then soldering the Nikon wire to the Pentax shoe mount. Someone else suggested an RJ45 network cable might work.

I also pointed out using a wired connection for a one flash off-camera HSS setup. My concern is will a Pentax TTL cable work for P-TTL connections?

I have an entire set of tools and supplies for any CAT5 cabling job. You can pump video down that stuff, but it never occurred to me to make my own flash extension cords. Thanks for the tip!

[maxfield_photo]

I also pointed out using a wired connection for a one flash off-camera HSS setup. My concern is will a Pentax TTL cable work for P-TTL connections?

Yes, I can confirm that TTL cables work just fine as pTTL cables. The pins are in the same position, so it doesn't matter to the wires what kind of protocols they are transmitting.

The one thing that worries me about ethernet cables is getting the right wires to the right contacts in the plug. Seems like if you cross wired it, you might fry either the camera or the flash.

[JimJohnson]

Yes, I can confirm that TTL cables work just fine as pTTL cables. The pins are in the same position, so it doesn't matter to the wires what kind of protocols they are transmitting.

The one thing that worries me about ethernet cables is getting the right wires to the right contacts in the plug. Seems like if you cross wired it, you might fry either the camera or the flash.

So long as you use the connectors as shown in the video, CAT5 cables are wired straight through (unless explicitly labeled as "cross-over"). You don't have to worry about buying ready-made stuff off the shelf. The biggest risk is in cutting the existing cable and adding your own RJ-45 connections.

[Alizarine]

I've read this on strobist:

Strobist: Lighting Tip: Neuter Your SC-17

is it only possible on Nikon cameras or can we also do this for Pentax? I mean, even 1/1000 sync is already mega-cool. really far off our 1/180

[maxfield_photo]

is it only possible on Nikon cameras or can we also do this for Pentax? I mean, even 1/1000 sync is already mega-cool. really far off our 1/180

You can make the cord he describes, but it won't let you raise the sync speed over 1/180th. Nikon cameras lock the shutter speed to 1/500th when they detect a TTL flashgun, but Pentax cameras don't even check for one, they just disable all sync commands above 1/180th. I actually managed to make one last night, unfortunately I was trying to make a TTL cord, hehe (I think one of my wires isn't all the way in the RJ-45 plug)

[JimJohnson]

I've read this on strobist:

Strobist: Lighting Tip: Neuter Your SC-17

is it only possible on Nikon cameras or can we also do this for Pentax? I mean, even 1/1000 sync is already mega-cool. really far off our 1/180

So far as anything I have read, all current Pentax bodies will disable the flash trigger at shutter speeds greater than 1/180th second, unless the body can detect a flash currently capable of High Speed Sync (HSS - also known as FP) . HSS flash on a Pentax body requires the use of P-TTL.

For reasons given in earlier posts in this thread, I consider HSS flash to have limited use in flash photography.

[maxfield_photo]

Success! I now have a 25 foot TTL cord using the Cat5 method. I think for off-camera HSS this is going to be the best solution, at least the way I intend to use it. With careful framing, I should be able to get the flash within 1 meter of my subject, but still be 20 feet away. This should strong enough to get the skies fairly dark, even at noon.

A couple things that I learned in making mine:

• It's hard to strip coiled cable, and man are those TTL cords well insulated.
• You don't have to pre-strip the ends of the inner wires, in fact, don't. When you crimp the RJ-45 plug there are little copper blades that push themselves down into the wire.
• I had 5 insulated wires and a bunch of loose copper threads in my cable that had to be twisted into a wire, I think that is probably the center pin. Some other cables I've seen have 6 insulated wires.
• In order to keep frayed ends from the twisted wire from sliding into the wrong channel on the plug, position that wire to one side, and all the other wires on the other side of the plug. That should leave a buffer of two unused channels between the twisted wire and the next closest.
• It doesn't matter what order you put the wires in, but you absolutely must do it the same way every time you crimp one, or you're liable to fry your camera and your flash. Mine went copper, empty, empty, white, green, yellow, red, black. Your colors may be different.
• Trim all the inner wires to the same length, and make them short enough so that you can fit a bit of the outer insulation inside the RJ-45 plug when you crimp it.

I'll see if I can get some samples this weekend of shots using up-close off-camera HSS.