Loyal Site Supporter Registered: December, 2017 Posts: 1,138
6 users found this helpful
| | Review Date: January 7, 2018 | Recommended | Price: $109.00
| Rating: 8 |
| Pros: | Can be used with SMC Pentax FA 645 Macro 1:4 120mm lens | | Cons: | Could use an intermediate speed between its f/5.6 and f/22 settings | |
This is intended to supplement the basic flash data. Photographic results will have to await film development and printing [and the fullness of time -- see below].
The goal was to operate a TTL-capable ring flash on my 645n when using its 120mm Macro lens. My existing ring flash, a Cokin, does not do TTL. The AF140C has a clear aperture of 55mm, whereas the lens has a 67mm filter thread. If the 67mm filter thread does not vignette the lens at f/4, then it is possible to show geometrically that at the f/22 setting, there is no blockage with a 55mm clear aperture, and at the f/5.6 setting there can be no more than a half millimeter of blockage at the corners of the field with this clear aperture.
To adapt the AF140C to the macro lens, a 67-58mm reducer ring is required. I acquired a senseiPRO ring for this purpose. To this is mounted the supplied 58mm thread adapter ring onto which the ring flash attaches by push-button latches.
At both of the two f/no. settings, the AF140C is bright enough against the photo targets (orchids) and/or their background (I was using gray paper) to trigger a pair of AF500FTZ flashes in slave mode located to the sides and behind the plane of the camera.
The AF140C communicates with the display in the 645n viewfinder.
As far as I can tell, the AF140C system I purchased was new and complete. It is provided in a padded leatherette box with snap cover. tI has a printed operating manual. Manuals may also be found in web repositories, and are recommended to potential buyers.
Edit 5 Aug 2018: Here is an example image taken as described above and scanned from the negative at Photosmith, Dover NH. The orchid is Phrag. Memoria Julius Dixler x boisserianum. One may observe that the shadows indicate that the fill lights are slightly less powerful than the ring light in this setup.
 | |
;)
;)
;)
