Ring Flash On Pentax DSLR

Hi

There are a few topics on ring flash, but several are rather dated and I was wondering if anyone has an update, now that there a a few units that are compatible with Pentax DSLRs? I'm interested in macro photography such as photos of acupuncture needles in situ and some other relatively close up work.

There seem to be 4 types -

1. the cheap ring lights,
2. the adaptors that convert a stanadrd flash ino a sort of ring output, 3. the ring flash units that will work with the Pentax and other DLSRs, but are manual only,
4. the fully integrated types with different versions for Pentax, Canon etc. such as Sigma and of course the Pentax AF160.

I'd opt for the Pentax unit, but it does seem very expensive in the UK and I'm tending towards the Sigma unit. Does anyone have a view about the need for full integration, or do the manual types work OK?

The manual types work fine, as long as you understand how to use your camera and flash in manual.

Peter

Thanks for your input. Forgive my ignorance, but for example if doing a face shot, would it be possible to use red-eye reduction in manual mode?

The short answer is yes . . . and no.

If you are using a totally manual flash set to more than 50% output power the answer is probably no, it won't work.

The flash will discharge at the set level for the red-eye and will have to recharge before it can fire again.

Re-charging will probably occur far too late for the second (exposure) flash to fire.

If however you set the output power such that you can get two flashes in quick succession, (1/4 power or less) it should work. Both the anti red-eye flash and the exposure flash will occur at the output power you have set.

That said, when I tried my Pentax AF540FGZ in manual mode and full power, the red-eye function worked fine giving a short flash duration first, then a full power flash shortly afterwards.

The same was not true for my manual AF240FT flash when set to 'H'. On 'L' (low output) it worked fine, hence my answer above.

Hope that helps.

Peter

Thanks again for this comprehensive answer. I just need to find out how well the available manual ring flash models work!

Does anyone out there have any experience of using a manual ring flash - such as the Sunpak 16R or the Metz with a Pentax K10?

Last week I found a Devon Camera advert for an unused Sunpak DX8R ring flash without mounting module. I was able to obtain a new module from the USA which arrived today. So, after delivery charges, for just under £100 I have a new Auto/Manual/TTL Ring flash. Enough to pay, I thought to try and see if I enjoy macro. P.S One has appeared on ebay.

Barrie

Interesting - can you let me know how you get on with this one?

Will do

[IMG]http://i679.photobucket.com/albums/vv154/bforbes/IMGP5357.jpg[/IMG]
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[IMG]http://i679.photobucket.com/albums/vv154/bforbes/IMGP5352.jpg[/IMG]

All taken with ring flash on auto mode, 1/180th@f8 ISO 100. I think #2 is under exposed but don't know why. C&C please

I have an 'ELICAR' ring flash I got for £5 at the camera club and it has a 49mm fitting for screwing onto the lens-- I have used it with my K10D Digital with my 1979 50mm SMC Macro-Takumar screw lens and it works OK then I have held itover the lens of my Pentax 6x7 and it works OK !

Barrie

Thanks for a sight of your trials with your Sunpak.

As you say, #2 seems under exposed. I did think that #1 might have been a bit over exposed, but it looked much better when I viewed it on my main machine, which has a much better monitor, so I think that's fine. I'm not sure about #3 - the catchlights on the apple are a bit fierce!

It's encouraging for a relatively small outlay, I'd say.

The thing I don't understand is why #2 is underexposed, when it's taken at the same settings as the others. As for #3 I did read somewhere that ringflash does not deal with reflective surfaces well. As you say for the price it was worth a go.

If your camera was set to Manual exposure mode and the shutter/ISO/aperture settings remained the same and the output power of the flash was the same in each case, only 2 things could have caused the underexposure assuming the flash was not in any 'auto exposure' mode:-

1: Flash to subject distance was greater in the underexposed image. Or
2: Camera or flash didn't work as expected. That is to say, either the shutter/ISO/aperture setting was not correct at exposure time, or the flash output power was not the same in each case.

Have you checked the EXIF data to ensure that all camera settings were the same?

Thanks Peter. The camera was set on "X" mode with the ring flash on Auto mode. According to the EXIF data they were all 1/180@f19 with ISO100. The f19 confuses me as the back panel of the flash gives an aperture of f8 for ISO100 and I'm almost sure that is what I set.

It'll be the auto flash that caused the problem then as it's output/flash duration would have been determined by an on-board sensor, and it got it wrong.