AF 160fc- macro attachment

Hello guys,
I have just uprgraded from the 140c to the 160c.
The 160c comes with a tube attachment for the macro lenses ( in my case the 100mm), as well as as a set of adapter rings.

The tube attachment substantially increases the minimum distance between lens and subject, thus reducing the maximum magnification.
Does the tube have a particularly necessary function in relation to the new flash, or can I use the adapter rings, as per my old ringflash?
This is important as I need to get close up to my subject (clinical dental photography)
Thanking you

Neil

Hi,
If you look on page 10 of the Flash Manual you will see that the "TUBE" is in fact a macro adaptor for the DFA Macro lens.

The other rings can be used as per any other flash - to fit the unit to a particular size lens filter ring - in this case 49mm 52mm 58mm and 67mm.

Hope this helps

The 'tube' is a bayonet fitting for the D-FA 50 and 100mm Macro lenses. If yours is not a D-FA lens, use one of the adapter rings.

Thank you gentlemen.
I use a 100mm DA lens, originally with the af 140C using the rings.
I was thus able to get closer to the subject.
The coupling tube increases the flash -sensor distance by the length of the tube (approx. 6cm)
Since the purpose of ring flash is for close up work, I just wonder in terms of physics and optics, what benefit the tube is giving over and above a coupling ring? as I now need to increase the aperture by a stop to compensate.
Neil

Sorry Neill, your lens identification is still incorrect. Pentax do not make a DA 100mm Macro lens. So which is it, FA or D-FA?

Whichever, if it has a filter ring, and I'm sure it does, just use the correct sized aluminium ring adapter.

I don't know what benefit the tube has, I don't use it.

Pete, The tube is designed to take the weight from the flash head off the focus barrel on the D-FA macro lens, with the tube attached to the hood bayonet all the weight is then concentrated onto the main barrel of the lens.

The D-FA 100mm macro does not have one of the highest build qualities.

I wonder if that is the Tokina influence at work again, was this not another joint venture between Pentax and Tokina?. I Must admit I'm surprised at the quality of the D-FA lenses, especially after the FA Macro.

Thanks for explaining Steve. I knew there would be a good reason.

Perhaps it's not a good idea to hang the flash head from the filter thread of a D-FA lens then ! ! !

I wouldn't hang anything from the barrel of a D-FA macro lens, any excess weight causes the focus barrel off kilter and that renders the quick shift inoperable. I found that out when trying some reverse stacking with a 50mm 1.7 attached. not a pretty sight.