Sunday, June 23, 2013

The User's Review: Vivitar 28 mm f2.5 Lens with a Konica AR Mount

The front ring with a 67 mm filter thread looks like a hood, does not turn but extends forward about 1 cm while focusing the closest.   

The red dot, mounting-alignment mark, is located a little bit
far away from the mount; The EE aperture lock is extended
outward too much., accidentally unlocked by my left hand.  

Saturday, June 22, 2013

The User's Review: Minolta Mini Beer Can Maxxum AF 35 - 70 mm f4 Macro Zoom Lens, Released in 1985

Like its bigger brothers, this mini lens is well built although the lens barrel is made of plastic. Push the Macro lock to set the focus range into or out of macro. In the macro, AF does not work. The dedicated hood can be put on backward to reduce the length and to protection the lens when the hood is not in use. The front piece of the lens not only turns when focusing but also extends when zooming.


The User's Review: Pentax SF10 35 mm AF Camera

1. Roof-mounted LCD display

2. Right-side-mounted hot shoe, located in front of the shutter button. The shoe is a regular one, but its cover is dedicated.

3. Well-built and solid body. Although the body shell made of plastic, feel very good quality.

4. Bigger body size. It's the right camera for you if you have bigger hands.

Friday, June 7, 2013

The User's Review: Comparison of the Two AF Lenses with the On-Lens Auto-Focus System by Chinon

In this post, I put the 'very impossible' and the 'even very impossible' (M. Butkus) side by side, and make it possible to show them for you.

On the ring plates around the front elements, these two lenses are marked as 'Auto Chinon Multi-Coated  1:1.7 50mm Japan 58Ø' and 'Auto Chinon Zoom MC 35-70mm 1:3.3-4.5 Japan', respectively. These marks are confusing because 'Auto' also marked on some of Chinon manual focus lenses. I believe, Chinon's 'Auto' on the these lenses means auto-aperture while the 'AF' signs on the AF system case of the auto-focus lenses indicate auto-focus.

AF Prime Lens
AF Zoom Lens
Contact pin
3 in one line
Focus length (mm)
35 – 70
Filter size (mm)
Lens cap (mm)
1 for both power & beeping
1 for power & 1 for beeping
Aperture ring
Partial covered by AF case
Aperture size marks
2 sets on the ring
1 set on the ring
1.7, 2, 2.8, 4, 5.6, 8, 11, 16, 22
3.3, 4, 5.6, 8, 11, 16, 22
Lighted aperture
Aperture blades
Focus distance marks
1 (3.5) – ∞ m (ft)
0.5 (2) – ∞ m (ft)
Battery power
Weight (g)
*The focus ring accepts a 55 mm filter. However, it will block the zoom to be set to 
  35 mm after the filter is installed.

Thursday, June 6, 2013

The User's Review: Auto Chinon Multi-Coated 50 mm f1.7, One of the Early AF Prime Lenses

This is a totally standing-alone AF lens although it was released as a Chinon lens. Its AF sensing and driving systems are located in the front of the K mount and without any AF control across the mount, making it an universal AF lens for all K-mount manual and AF SLR and DSLR bodies, theoretically. However, this AF lens can not be mounted on a body with a projecting eaves above the lens mount (e.g., Pentax K-x DSLR) because the eaves and lens case around the mount block mounting.   

It looks funny, strange, or professional?

Once installed, press this green button to go for AF. Its AF speed is acceptable although not as fast as the modern AF systems.

The focusing can also be set manually.

The green LED and a beep tell you 'in-focus'. The green light also falls down to the aperture size marked on the aperture ring that is shown in the v-shape opening above the lens mount. The lighten aperture size can be pick up by a aperture window on camera such as Pentax KX in order to display in the camera's viewfinder. A great design. There is another set of aperture size marks (on the left in the image above) for reading from the lens body directly.

It's manual are in multiple languages. The section in English is posted here.

The case and barrels of Chinon Auto Focus 50 mm 1.7 are made of plastic. I do not open it to look, but will put a question mark behind its durability.