Saturday, 17 June 2017

Pregnant Lens: SMC Pentax AF Zoom 1:2.8 35-70mm

Cost: $35 (average market price $115.80)


Collectors item alert!! This lens is regarded as the first auto focus lens on the market. For sure the first Pentax auto focus lens. The autofocus motor is build inside the lens, including space for AAA type batteries, giving this lens the appearance of a "pregnant" lens, ready to pop out a few small baby lenses... The autofocus only works on Pentax ME-F camera, but can still be used manually (push/pull type) on any Pentax PK compatible camera.

Due to the complexity of the build-in auto focus, Pentax had to make sure that the lens had constant aperture across the full zoom range, resulting in the fastest 35=70mm zoom that Pentax ever designed. The motor also increased the weight, making this a bulky heavy lens. And the design also left a minimal manual focus ring with only a quarter turn across the whole range, making this lens a little less friendly to use, and slightly harder to focus.

The lens also features a unique red coating that I have never seen on any other Pentax lens. But the colors are nice and saturated, requiring minimum post editing, and the lens has reasonable to good sharpness across the whole aperture and zoom range.

Pentax never made any other SMC Pentax-AF lens. Although a decent lens with a solid metal build quality, due to the unfriendly handling, it is mostly a collectors item, taking a well deserved place in Pentax history. A keeper for sure, but mostly to put on the shelf.

Lens Specification:

Focal Length: 35-70mm
Maximum Aperture: F2.8
Minimum Aperture: F22
Image Format: 35mm
Lens Mount: PK
Optics:7 elements in 7 groups
Blades: 8
Focussing: Manual, Auto Focus on Pentax ME F only
Minimum Focus: 120cm (unknown in macro mode)
Maximum Magnification: ?
Filter Size: 58mm
Weight: 580g
Length: 77-110mm
Production: 1981 to 1988
Serial Number: 8082341
Made in: Japan by Asahi Opt.Co.

More information on Pentax

Samples:
Pictures made with Lens Turbo II adapter

1/160s - ISO200 - Handheld

1/160s - ISO200 - Handheld

1/160s - ISO200 - Handheld

1/160s - ISO200 - Handheld

1/60s - ISO200 - Handheld
1/800s - ISO200 - Handheld

1/500s - ISO200 - Handheld

1/640s - ISO200 - Handheld

1/640s - ISO200 - Handheld

1/1250s - ISO200 - Handheld

1/1250s - ISO200 - Handheld

1/200s - ISO200 - Handheld - Cropped
Sources:

Sunday, 4 June 2017

Monster Lens: MC Soligor C/D Zoom+Macro 75-250mm 1:4.5

Cost: $19.99 (average market price unknown)


A monster of a lens. With close to a kilogram and almost 20cm long, you know you are carrying a big lens. It also make it hard to keep stable, as there is no tripod mount on the lens itself. Almost a must for a lens this size and weight. Build quality is nice, all metal, constructed like a tank. Smooth aperture and focus rings but with a little barrel creep when pointing the lens down (not uncommon with large push-pull type of lenses). Just looking at this lens, you expect great results! But that's where it goes wrong....

This is probably the worst lens I have encountered. Not sure if it is my copy, the adapter, or just the quality of this lens, but the lens lacks sharpness across all aperture and focus ranges. The lens might be able to make sharp pictures (I had a few sharp ones), but it was very hard to focus, even on a tripod and using live-view. The lens has two focus rings, one for tele, and one for macro. It made it very confusing to use this lens, and often resulting in messing up the sharpness. The macro ring can also be used to introduce some softness, but that's not something most people want.

It's nice that it is constant aperture across the focus range, but that was the only plus point I could find. I plan to divest from this lens in the near future and let someone else give it another try.

Lens Specification:
Focal Length: 75-250mm
Maximum Aperture: F4.5
Minimum Aperture: F22
Image Format: 35mm
Lens Mount: PK
Optics: 13 elements in 10 groups
Blades: 6
Focussing: Manual
Minimum Focus: 250cm (unknown in macro mode)
Maximum Magnification: 1:1.8
Filter Size: 62mm
Weight: 845g
Length: 171-181mm
Production: 1981
Serial Number: 381004390
Made in: Japan by Sun Optical

MC
Multi Coating of the lens to combat partial reflection,

C/D
C/D or "Computer Designed" or possibly "Compact Design" was Soligor's designation for their premium lenses, similar to the Vivitar Series 1 lenses.

Samples:

1/100s - ISO100 - Handheld

1/100s - ISO100 - Handheld

1/100s - ISO100 - Handheld

1/100s - ISO100 - Handheld

1/250s - ISO320 - Handheld

1/250s - ISO800 - Handheld

1/640s - ISO800 - Handheld

1/125s - ISO800 - Handheld

1/125s - ISO800 - Handheld

1/1000s - ISO200 - Handheld

1/1250s - ISO200 - Handheld

1/640s - ISO200 - Handheld

1/1250s - ISO200 - Handheld

1/1000s - ISO800 - Handheld
Sources:

Friday, 2 June 2017

Unknown for a reason: Lenmar 28mm 1:2.8 MC

Cost: 7.99$ (average market price unknown)

As they say, it's hard to screw up a prime lens... And this lens is the exception. Not sharp at all, especially in the corners, creating a soft feel to the pictures.  Some chromatic aberration and easy to over-expose highlights. I also did not like the color, resulting in washed out, blue-ish, pictures.


The lens does feel solid, is good looking, has an all-metal build and has some real smooth focussing , almost like a older Pentax lens. But image quality is so low, that it outweighs the looks and build. Maybe I just have a bad copy...


I don't believe I will keep this lens in my collection. I have way better 28mm lenses and I don't believe it has any collector value.


Lens Specification:
Focal Length: 28mm
Maximum Aperture: F2.8
Minimum Aperture: F16
Image Format: 35mm
Lens Mount: Pentax PK
Optics: Unknown
Blades: Unknown
Focussing: Manual
Minimum Focus: just under 150cm
Filter Size: 55mm
Weight: 229g
Length: 48mm
Production: 1970's
Serial Number: 28505
Made in: Unknown

Company:               
Lenmar was a rather unknown American electronics supplier to stores such as Best Buy, etc... Not sure if it is related to the present company under that name. They re-badged mostly low-quality lenses and don't seem to have a good reputation for their lenses. 

MC
MC, or Multi Coated, stands for a multiple of chemical coatings for lens surfaces with minimum light loss. The result is a dramatic improvement in both color fidelity and brightness and the elimination of flare and ghost images.

Adapter:
Lens Turbo II PK - Nex
Cost: $75, used on B&H PhotoVideo, new for $149

The Pentax K Lens to Sony E-Mount Camera Lens Turbo Adapter Mark II from Mitakon allows Pentax K lenses to be mounted on Sony E-Mount APS-C format cameras, increasing the angle of view by 0.726x and the maximum aperture of the lens by 1 f-stop.The four optical elements of the Lens Turbo adapter condense light from the Pentax K full frame lens and project it onto the camera's APS-C sensor allowing the sensor to capture all of the lens' transmitted light, negating the 1.5x crop factor and effectively producing full-frame coverage on non-full-frame sensors. A corresponding increase in the maximum aperture of 1 f-stop makes the lens more effective in low-light situations.



The Mark II version of the Lens Turbo features an improved design to produce sharper images. Its rectangular rear lens rests closer to the camera's sensor improving light transmission and an enhanced lens coating minimizes ghosting and flare. One extra-low dispersion (ED) lens element reduces aberrations for better delineated images. The adapter offers a sturdy metal construction and stainless steel mounts, it attaches to both camera and lens with little play and includes a front and rear protective cap. The Lens Turbo is a manual adapter offering no electronic communication between lens and camera.

Samples:
1/125s - ISO100 - Handheld

1/250s - ISO100 - Handheld

1/800s - ISO100 - Handheld

1/400s - ISO100 - Handheld

1/500s - ISO100 - Handheld

1/250s - ISO100 - Handheld

1/500s - ISO100 - Handheld

1/100s - ISO100 - Handheld

1/60s - ISO100 - Handheld

1/60s - ISO100 - Handheld

1/125s - ISO100 - Handheld

1/30s - ISO100 - Handheld
Sources:
Pentaxforums