[bluestringer]

I am getting one of these but it only comes with the standard module. Will this work on a Pentax in manual mode, or will I need the Pentax module? I don't need auto, as I will be shooting in manual anyway.

[SOldBear]

It will work with the standard module. In fact, it will work with any module.

The only thing the Pentax module adds is: if the camera is in Av mode, when the flash is ready, it sets the shutter speed between 1/30 sec and 1/180 sec, depending on the focal length of the lens.

[bluestringer]

Thanks SOldbear. I'll be using my Pentax M 100 macro most of the time, so I'll be shooting in manual anyway. Do you happen to know where I can ind a PDF manual for the DX-8R.

[SOldBear]

Note that DX-8R auto mode does work, even without the dedicated module for the camera. Just set shutter speed at 1/180 sec or lower, match the ISO setting and the aperture setting on the camera with those on the flash, then shoot.

But the problem is that (1) in macro focusing distance, the aperture of the lens can be 1 (at 1:2) or even 2 (at 1:1) stops lower than "nominal" aperture setting and (2) the exposure is based on "average" light reflected from the scene, which in most macro shooting situations, is not "average" at all.

Like you, I mostly use manual mode. The DX-8R has 5 power ratio settings (1 to 1/16), which helps a lot.

Manual is here -> linky.

[bluestringer]

Thanks. I figure I will have to do some experimenting to get the right exposure, but it's good to know it will also work in auto mode. That's the way I use my AF280T, and it works well using it like that.

[SOldBear]

You can make a "quick release" for your flash.

1. Obtain a Raynox Universal Adapter, the one that comes with the Raynox DCR-250 or DRC-150. If you don't have it, you can buy the Raynox Universal Adapter for Raynox CM-2000 Macro Lens for about $10 + shipping. Do NOT buy the Raynox Universal Adapter for Raynox CM-3500 Macro Lens because its opening is very small (37mm). Use epoxy to glue a 67-58mm step down ring to the adapter. Note that the "fat" face of the step down ring is against the Raynox adapter. You need as much gluing surface as possible.




2. Attach a 58mm adapter ring (essentially a 58-52mm step down ring) to the flash:




3. Screw the flash and the Raynox adapter together:




Bingo! Now the flash can be instantly attached to/detached from any lens with filter thread diameter from 52mm to 67mm. This is the flash attached to a Tamron 90mm macro lens (55mm filter thread):




Of course you'll have to watch out for vignetting because the opening of the Raynox adapter is only 43mm. But I don't have vignetting problem with my Tamron 90mm and Sigma 50mm macro lenses.

You can choose to glue, say, a 62-52mm step down ring to the Raynox adapter (step 1), then you can just attach the Sunpak flash to the Raynox adapter (the Sunpak flash has 52mm diameter). But then the Raynox adapter is "dedicated" to the Sunpak flash because it can't accommodate the Raynox lens any more.

If you use a 67-58mm (a 62-58mm will also do, but you don't have as much gluing surface), the Raynox adapter can still be used for the Raynox lens:




Do not attempt to attach the Raynox adapter to lens with filter thread smaller than 52mm. You may break the "ears" of the adapter.

[bluestringer]

It arrived today. It actually came with the Nikon module, and not the standard. Seems to work ok. Here's a test shot sitting at my desk. I think it'll be worth the 50 I paid for it.

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Last edited by bluestringer; 03-24-2012 at 04:20 PM.

[SOldBear]

I think it'll be worth the 50 I paid for it.

It's absolutely worth $50. You'll be happy with it (looks like you are already).

Interestingly, late last year, just getting a copy of its big brother DX-12R, I tried to sell a copy of DX-8R (I had two). No one took the offer at $55 including US shipping. I ended up giving it to a friend of mine. My "good will" cost him $400. He had to buy a macro lens just because he couldn't stand the ring light being unused!

[alohadave]

I think it'll be worth the 50 I paid for it.

Definitely. I paid $100 each for the ones that I have. (DX-8R, GX-8R, and DX-12R)

[v.i.guy]

Just scooped a MIB DX-8R with the standard module...$40 from a local seller. Few test shots at 1:1 @ 1/16 in manual were well exposed but the smell of hot electrical stopped me dead...either this flash has only been fired a couple of times in it's life or the trigger voltage is high. The manual doesn't state the voltage, so does anyone know their voltage, test procedure or link to ease my mind...

[v.i.guy]

Just scooped a MIB DX-8R with the standard module...$40 from a local seller. Few test shots at 1:1 @ 1/16 in manual were well exposed but the smell of hot electrical stopped me dead...either this flash has only been fired a couple of times in it's life or the trigger voltage is high. The manual doesn't state the voltage, so does anyone know their voltage, test procedure or link to ease my mind...

...opened my eyes and found your test procedures... I'll check after some sleep...
https://www.pentaxforums.com/forums/pentax-camera-field-accessories/85088-sunpak-autozoom-thyristor-933-a.html#post1712836

[Jimmy_Dean0]

I picked up a DX-8R locally yesterday for $40 (new in box no less!). It has a Minolta module on it, and checking the trigger voltage shows 1.85 volts. Trigger voltage on my Pentax flash indicates 2.7 volts, so I'm thinking it should be safe to use on the K-5. It fits beautifully on the 50 F2.8 Macro. Does anyone have experience with this unit on a K-5? I have tested it with a wireless trigger and it does work, but it is somewhat awkward to use that way.

[Jimmy_Dean0]

After much researching and reading I decided to test the DX-8R on the K-5 and it seems to work without an issue, even with the Minolta module, though I had to use it in full manual mode. Hope these links work

https://picasaweb.google.com/110473820339027157543/RingFlashTest2012_07_08?a...36306743951362


https://picasaweb.google.com/110473820339027157543/RingFlashTest2012_07_08?a...41251124184498