Spacecom 16mm f/1.4 2/3″ C Mount Pyxis on Pentax Q
The Q with its tiny sensor needs very large aperture lenses to shine, does this classic 85mm equivalent do the trick?
This 16mm f/1.4 lens is equivalent to an 89mm on full frame making it an classic portrait/mid telephoto focal length. Now the f/1.4 * 5.5 crop factor equivalent aperture of f/8 might not sound impressive, the shorter physical focal length means the lens has a much closer minimum focal distance, meaning you can actually get shallower depth of field than you can on the full frame with an 85mm f/1.4 since you can focus mere inches away, but you will have tighter framing in that circumstance.
Spacecom must be using some OEM lens, or maybe is the OEM for this 16mm f/1.4, I think the Pentax 5 MP 16mm f/1.4 2/3″ is actually the same lens based on what I can tell from the specs, but I could be wrong. The pricing on this Spacecom was more affordable for similar specs so I ended up with it, even though it doesn’t look as nice as the Pentax with its red stripe.
Getting down to business, the lens is nicely made with all metal exterior construction, decent looking AR coatings. Both the front and rear elements have multi layer coating on them. Focus is smooth, but loose feeling and makes a light scraping noise, I think the mechanism used for tightening it down with the locking screw.
There are locking screws for the aperture and focus ring, I will probably take these out, but are great if you want to prevent an accidental focus change. The aperture ring has nice click stops so probably doesn’t need the locking screw. The lens caps were very cheap plastic slide on caps that could be replaced with something better. This type of lens is often designed to be used on a video camera 24 hours a day so caps are not necessary other than to protect in transit.
The lens is on the large side compared to the Q standard zoom, but is well sized. I think any smaller and it starts to be more difficult to manual focus. The filter threads are 49 mm, with a nice star shaped 10 bladed aperture (it is wavy and changes shapes at various apertures). Focus is from a nice close 0.2 m (7.9 inches), compared with about 0.85 m (2.8 feet) for most 85mm lenses. Weight is noticeable but not heavy at 200 g, very nicely weighted with the dense little Q camera. The lens retails for approximate $190 US.
This lens claims to have 5 MP resolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point., whatever that means. The manufacturer doesn’t advertise how to they came to this number, and they also claim 145 LP/mm across the frame, but they don’t state at what contrast. I will comment on how it performs at the end.
Lets get on with the review:
Optical Performance
Please click on the tab you want to view. Only 1 tab may be active at a time. MTF, Distortion, and Lat CA data acquired using
ImatestComments on the Results
This lens has flat resolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. and sharpnessI use this to refer to the MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. will have a short transition period between a white and black edge. across the frame. This lens performs about the same at f/1.4 as the Pentax 02 prime at 15mm f/4.5. The lens is good at f/1.4 for close up and available light photography, and by f/2 or f/2.8 it is at good levels for the Q, for MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. we are resolving about 155 lp/mm and for MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. about 240 lp/mm. So I think the camera holds up to the claim of 145 lp/mm across the frame. Even wide open it will hit this for MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point.. The 5 MP claim is for a 2/3″ sensor.
Distortion is negligible.
Lateral CADifferent wavelengths (colors) of light have different magnifications and produce colored halos around high contrast objects near the frame edges. is slightly noticeable. Longitudinal CADifferent wavelengths (colors) have different focus points, causing colored halos in out of focus regions of the image; typical is magenta in front of focus plane and cyan behind. is fairly noticeable which will lead to some purple fringingPurple fringing occurs around high contrast edges in a lens with high longitudinal CA in the focused areas; the slightly out of focus red and blue are fairly balanced and combine to create a purple halo. The sensor microlenses and color filter can aggravate purple fringing as well..
The lens is susceptible to veiling glareA specific type of flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame. in contra light where the overall sharpnessI use this to refer to the MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. will have a short transition period between a white and black edge. of the image is reduced but resolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. remains. Large glass elements, scratches, fungus, and poor/no optical coatings can lead to veiling glare. A lens hood can reduce this type of flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame. dramatically. and aperture ghosting. There is maybe a bit of a white balance shift from f/1.4 to f/2.8, that the AWB will take care of automatically, but you might notice it in RAW. It isn’t too significant, just something to be aware of.
I measured the corrected focal length to be 16.1mm based on 1:197 magnificationHow large an image appears on the image sensor compared to how big it is in real life. Life size magnification means the image is the same size as the real object. My charts are photographed at 1:53 magnification, so if I photograph an area 53" wide it would appear as 1" wide on the sensor..
Pros and Cons
- ResolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. across the frame from f/2
- Surprisingly good at f/1.4
- Subject isolation good for sensor size
- Longitudinal CADifferent wavelengths (colors) have different focus points, causing colored halos in out of focus regions of the image; typical is magenta in front of focus plane and cyan behind.
- FlareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame.
- Focus ring too loose
Bottom Line
This lens is a good value lens. Much closer minimum focus distance and 2 stop larger aperture than Pentax 06 telephoto, and much better performance and 3+ f/stops larger aperture than Pentax 02 standard zoom, make this lens and excellent manual focus no brainer.
ResolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. seems close to the values tested on the wider end of the Pentax 02 zoom, which are quite good. It is by no means compact like the 01 Prime, but makes it easy to support the camera with your left hand underneath and still it isn’t huge, although it makes the camera less pocketable.
I was immediately pleased with the images, and the lens should be decent at HD video at all settings (want about 1080 LW/PH for HD), and makes a nice classic portrait lens on the Q. Just remember you won’t get the same object separation at a distance like you would with a full frame 85mm f/1.4, but up close this lens shines and you will get a lot better depth of field control than either kit lens at about the same focal length. It actually performs fairly similar to what an 85mm would on full frame (susceptible to flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame. and longitudinal CADifferent wavelengths (colors) have different focus points, causing colored halos in out of focus regions of the image; typical is magenta in front of focus plane and cyan behind.).
The lens doesn’t have the flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame. performance of the Pentax lenses, but definitely excels at sharpnessI use this to refer to the MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50I use this to refer to the MTF50 graph. This is how contrasty the lens is, and correlates with perceived sharpness. A lens with high MTF50 will have a short transition period between a white and black edge. will have a short transition period between a white and black edge., resolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point., and minimum focus. This is a great mid telephoto lens for the Q if you enjoy manual focus. Much better than other older manual focus lenses like the Pentax 110 18mm, and any of the VGA C mount lenses in that range, and the short minimum focus helps showcase one of the benefits of smaller sensor photography (short focal length lenses focus closer so your telephotos can focus very close)
Spacecom JHF16M-5MP 2/3″ 5 MP Fixed Focus Lens (16mm) on BHPhoto in the US to support the site.
You need a C mount to Q adapter as well!
Gallery
Gallery images have some sharpening (have to with Q) and some have minimal exposure adjustments, like some of the flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame. shots.
The gallery images are © 2013 Eric Tastad, and may only be used for personal evaluation of the lenses. Click the play button and click “visit gallery” in the upper right to download full size images.
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