Recommend Macro Ring Flash for K7

[MattC]

You can use a faster than 1/180 shutter speed with your Pentax DSLR as long as the flash supports it.

All bodies since the K10D allow you to select Hi Speed flash synch if a flash with that function is mounted. The Pentax 540 and 360 flash units both do it and so do some Sigma and Metz units. Not sure about the ring flash but check the specs.

How it works is to strobe the flash for an extended period so that you get the full frame despite using a faster than flash synch shutter speed. Without it you would 'chop off' one side of your frame.

Hope this is of some help.

Any tips on getting it to work -especially in wireless mode? I have found it to be an exercise in frustration, and now just shoot at 1/180th.

[Othrelos]

BTW the best way to avoid reflections is to use a polorising filter. However, this will cut down the light reaching the sensor so your flash will have to put out more light. A bit of a catch 22.

Using a polariser also makes the viewfinder darker, which makes manual focus much more difficult. I only use manual focus with my sigma 180mm f/3.5 - though to use the AF160FC ringflash I had to use a step down ring from 72mm to 67mm I was concerned about vignetting however even on full frame there isn't a problem with using the step down adapter in conjunction with the adapter rings for the ringflash. The Sigma 180mm f/3.5 [IF] APO EX DG can be a difficult lens to use hand-held with the pentax system in light of the 1/180th synch speed, I don't advise using HSS(high speed synch) with macro lighting because it really kills the power of the flash and for true macro work, HSS is functionally useless because of the reduction in flash power. With macro work in general, maximising DOF is very important and I need all the flash power I can get,incidentally the PENTAX AF160FC is a very powerful flash considering it's competition.

here are a few of my sample images, both were taken with the Sigma 180mm f/3.5 APO [IF] EX DG Macro.

[doppelganger]

Thanks for the comments, I'll post more flicks as I learn to fly it