AF160FC Ring Flash: In need of adaptor!


Link Posted 26/04/2021 - 07:31
The adaptor is 6cm in diameter




Link Posted 29/04/2021 - 18:20
This is one from my Canon Twinflash ... it looks very similar and they are easily obtainable

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Link Posted 30/04/2021 - 07:29
The Pentax ring flash adapter for the 100mm macro lens is like a deep hood which attaches to the body and not the filter thread. As the front element of the lens moves quite a distance when focusing I guess having the weight of the flash on the moving part would otherwise be detrimental to the lens, so that is something to bear in mind.


Link Posted 30/04/2021 - 09:32
If it helps, here are a few photos of the 100mm Macro Ring....

 you can see it's quite a bulky item


Link Posted 01/05/2021 - 03:01
Thank you everyone for the photos.

Does anyone have either the bulky adaptor or the adaptors that screw into the filter threads?

I am in desperation mode at this point


Link Posted 01/05/2021 - 11:45
The Sigma EM140 adaptors look very very similar, the diameter of the ring where the flash fits is 78mm, if the Pentax is the same diameter you may be able to use one of these.

Wex have them as special order, but the smallest appears to be 52mm but you could use a step up ring perhaps ( 10 for the adaptor and 6 for the step up ring )


" A Hangover is something that occupies the Head you neglected to use the night before".

K1 - Sigma 85mm F1.4, Pentax DFA 150 -450 F4.5 / 5.6, Pentax DFA* 24 - 70 F2.8

Sigma 100-300 F4, Samyang 14mm F2.8, Pentax DFA* 70-200 F2.8

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Link Posted 01/05/2021 - 11:58
It's one of the things that eally annoys me about Pentax, trying to get replacement accessories is just about impossible. A lot of hoods are unavailable and why not make the little plastic tabs on the hood for sale rather than having to buy a complete new one anyway.
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Link Posted 01/05/2021 - 15:06
Right, it's time for some lateral thinking...

A 58mm filter fits snuggly into the ring flash and the flash does a fair job of gripping the filter thread (just tried it). So perhaps a few step-up, step-down and reversing rings connected in appropriate order would be able to simulate the 49mm adapter for the ring flash - 49mm at lens end, 58mm at flash, then a bit wider (but not much) to stop the flash slipping off, a ring or two for padding at appropriate places. If it works, it would be a great triumph of human ingenuity at a time of great need . Does anyone with a big collection of rings fancy trying it?

Unfortunately, 58mm is my least popular lens diameter so none of my rings are any use.

And also unfortunately, 58mm means that Chrism8's Sigma adapter won't fit.



Link Posted 01/05/2021 - 15:38
A visit to might be worth a shot. There are some useful links on there


Link Posted 02/05/2021 - 07:35
Chrism8: I actually tried the adaptor rings for the Sigma ring flash. It was a pretty large mismatch

Another thing I have noticed is that I can actually get the flash to latch onto the area that the lens hood normally attaches to. BUT, the ring flash is just a tiny bit too big so when I tilt the entire unit down, the flash falls down. So I experimented and the grip of the flash to the lens hood attachment area becomes a little stronger when I turn the flash head a bit. I am not sure how to describe it but essentially, if the normal position of the flash has the Pentax logo of the flash unit at 12 o'clock, then turning the flash unit to 11 or 1 o'clock once latched onto the lens hood attachment area improves the grip. Enough so that I can actually tilt the entire unit down without the flash falling. However, it is still not super stable and since I am planning on using this in the dental setting, it would be quite the event if I do this and the ring flash does fall as it would end up landing on the patients face

At this point, I would not even mind buying the same flash again as long as it comes with the damn ring adaptors! The gentleman from the Japanese marketplace that I purchased this unit from is willing to take it back but I am still holding out for hope. if anyone wants to sell the whole unit, let me know!

Any ideas as to how I can potentially improve the grip even further? I have tried using elastic bands on the internal surface to try to improve the grip and even toyed with the idea of building up the lens hood attachment area with light-cured acrylic but I know that I will end up making the situation worse.


Link Posted 02/05/2021 - 16:40
How about foam draught excluder available from Wilko, Screwfix etc. A layer wrapped around the lens (or better still filter) should provide a firm grip. It will be a bit trial and error, but might be a short term solution.


Link Posted 04/05/2021 - 08:04
Taking the previous suggestion a bit further, I wonder whether something could be done with a lens hood? If the lens hood will fit in the ring flash, a bit of sticky-backed foam wrapped round the hood should provide enough grip. Does anyone know the dimensions of the hood for the 100mm macro? (I don't have the lens so can't try it out myself.)



Link Posted 04/05/2021 - 14:38
The 100mm lenshood is 6cm deep and 8.4cm diameter at the point furthest from the lens


Link Posted 05/05/2021 - 22:25

I thought of the same approach but unfortunately, the lens hood is much bigger than the diameter of the ring flash. The ring flash has no chance of fitting over the lens hood


Link Posted 06/05/2021 - 13:50
I have just looked at the SRB site for inspiration and came across this I wonder whether this would provide a 'platform' for the draught excluder idea

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