| Reviews : Rokinon 85mm f/1.4 Aspherical Lens for Pentax K20D K10D K200D K110D K100D *ist DL Ds Digital SLR Cameras |
Rokinon 85mm f/1.4 Aspherical Lens for Pentax K20D K10D K200D K110D K100D *ist DL Ds Digital SLR Cameras Product By Rokinon Available From 2 Sellers |
Technical Details
Product Description
The Rokinon 85mm f/1.4 Manual Focus Lens is an ultra-bright lens with a maximum aperture of f/1.4. Although you can only use this lens in manual focus mode, it is fully compatible with the automated features available with digital SLR cameras. It is compact and lightweight, and offers the ideal focal length and bright aperture for use as a portrait lens.
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Customer Reviews
By N. Savoiu
I wanted a fast 85/1.4 for some longer range portraits without breaking the bank. I heard about the various versions of this lens (Samyang, Opteka, Polar, etc) and it looked like a good lens especially considering the cost.
My impressions? Very well built with a smooth and dampened focus ring. Image quality is very acceptable even wide open but getting the plane of focus where you want it needs some practice unless you have an older split-prism focusing screen.
The hood is a bit flimsy but not to the point of worrying about it. The lens materials look to be of good quality minus the caps and hood which are a step lower but also not to the point of concern.
By Directed Energy (USA)
If possible, I would RATE THIS ITEM 3.5 STARS
I have been using the "Rokinon 85mm f/1.4 Aspherical Lens for Pentax K20D" for about a month and have gotten to know the lens well. On the whole, the optics are good but what degrades the users experience with this lens has less to do with the optics and everything to do with the lens housing mechanics and matching accessories.
Optically, I would rate the lens a B+/A-. As a previous reviewer has noted, the image sharpness does not improve much as you stop down the lens, but the lens is fairly sharp to begin with. What's important for such a fast lens is that wide open the images look nice and the Rokinon 85mm f1.4 lens has that covered. I have noticed that the lens is not equally sharp in all four corners of the field. Instead, the upper left corner is slightly softer than the lower right corner (see photo). This sort of minor zonal error suggest to me that Samyang, the manufacturer of this lens still has some work to do in terms of Quality Control and Process Engineering.
In terms of exposure accuracy, I find that the Rokinon 85mm f1.4 lens shoots a bit on the underexposed side. For that reason, I find myself having to adjust the eV scale on the K20D about +1/3 of a stop. If you are in a hurry, the extra time needed to set the proper exposure compensation can be an issue, as the time to adjust takes away from photographing the subject and can cause lost opportunities. This needed eV adjustment is also why some of the photos I have taken with the lens differ from average to nice. I wonder if the Rokinon 85mm f1.4 lens would be more accurately advertised if it were labeled as having a maximum aperture of f1.7 as appose to being a true f1.4.
From a mechanical perspective the lens is solid and robust. The down side is that the lens takes too much force (inertia) to get the focusing collar moving. I'm not sure if the barrel housing for the internal focus (IF) optics are machined with too much "tolerance stack up" or if too much or too viscous a grease is being used or if a vacuum is being created somewhere within the housing but the lens focusing collar needs much more than average force to start rotating. Because of this, it is difficult to stay manually focused on a moving object by focusing with 1-2 fingers on the underside of the lens.
When shooting a DSLR camera, for greater stability, I rest the camera body base in the palm of my hand and rotate the focusing collar with my fingers. Since this is a fast lens with a very short depth of field, proper focus is critical. With the Rokinon 85mm f1.4 lens, the stiffness of the focusing collar is such that it now degrades the users reaction time as far too much inertia is required to get the focus collar moving and an equal amount of inertia is needed to stop the collar from over rotating from the point of perfect focus. For that reason, I do not recommend this lens for sports photography or for objects moving at moderate speeds (10-15mph) or higher from a distance of 40-50 feet.
The Rokinon 85mm lens mount is not machined with great dimensional tolerance or accuracy. For that reason, the lens can and does rotate at the lens, camera interface about 1+ degree. This doesn't cause any harm for most situations. But, because the thrust surfaces on the lens mount is very snug each time a person rotates the focusing collar after mounting the lens to the camera, the pair, camera and lens make a clunking sound as the lens barrel rotates about in the camera mount hitting the lens registration stops on the camera body. This repeated impact between the lens mount and camera body mount may in time cause the mechanical stops to show wear marks prematurely. Regardless, the clunking sound makes the lens sound like it has been heavily used and tired.
As mentioned in a previous review, the front squeeze clip lens cap that comes with the Rokinon lens is very cheap and marginally functional. Specifically, the portion of the cap that seats against the front of the lens and clips on the lens external ID filter treads is too deep to fit well on most lens filters. The Rokinon lens cap has a deep threaded clip portion for securely holding on to the lens barrel (see photo). However, most filters by design do not have a deep external ID thread section so as not to vignette the cameras field of view.
Unfortunately, the front cap for the Rokinon 85mm lens does not fit well on to anything but the Rokinon lens and every cautious photographer I know uses a filter on the front of their lens to protect the front element. As a side note, since the front cap will not seat flush to a filter, the lens cap can and does, come off unexpectedly. If you plan to use this front lens cap with filter, I suggest getting a leash for the cap or you stand a very good chance of losing the cap.
Also, the supplied lens hood does not fit over the front of the clip on lens cap (see photo). The lens cap dimensional tolerances are so dismal, that the O.D. of the lens cap is about 0.010" too large in diameter for the supplied lens hood to slip over. For that reason, the user needs to remove the front lens cap first, and then mount the lens hood. Same goes for when one wants to remove the hood, you have to first remove the front lens cap, and then remove the hood. Otherwise, the front lens cap gets pulled off by the lens hood when one try's to remove the hood. I plan to take a file to the lens cap to solve the problem.
The rigid lens hood supplied with the camera feels flimsy, easy to flex in the hand and makes me concerned that it I will break in the field. I'm just a causal photographer, but this lens hood looks like even casual use may be over taxing. The hood, like most other hoods, twist on with a bayonet type of mount. The hood feels so weak that it makes me nervous to rest a K20D with BG2 battery pack, flash and lens against the front lip of the hood like I might do with some of my other lens.
Last, the Rokinon lens sock is the cheapest lens sock I have ever received. Worst of all, the sock is too small in diameter to fit around the supplied lens hood (see photo). Hence, if you plan to keep the lens hood with the lens, stowed with the hood draped over the barrel of the lens, then you will need to get another lens sock. I got a cheap slightly padded soft digital camera case from Sony (model LCS-CSD) that nicely fits both the Rokinon lens and hood in the stowed position.
The faux pas above clearly indicate that the designers and marketing team at Rokinon are remiss in their understanding of a typical DSLR photographer's very basic needs.
Lens was promptly shipped and well packed by Cameta Camera.
Minus 0.50 for too stiff a focusing collar for a manual focus lens.
Minus 0.25 for over all optical quality
Minus 0.25 for sloppy lens mount fitting.
Minus 0.25 for front lens cap and hood build, design and function.
Minus 0.25 for lens with hood stowed does not fit into lens sock.
By E. Higdon (Naples italy, Iraq, Afganistan anywhere the army ships me)
Decent bit of glass for what you pay.
I like it. Not the easiest thing to manually focus this lens on a dslr body. If i was strictly a digital shooter i would want to replace the focusing screen in my body to make using this lens easier. I shoot film as well so this stays on my kmount slr.
The bokeh is pleasant enough. The lens really shines when stopped down to f2.
I also own a 70mm sigma in kmount, and an 85mm in nikon mount. This lens competes very well with them for the portrait stuff i shoot. If it was an autofocus lens it would get much more use.
I can use it in aperture priority mode with no issues on my k10.
By E. J Tastad (Marion, IA United States)
Pros:
Image quality from wide open
Bokeh
Handling
Construction quality
Value
Video use
Cons:
Image quality doesn't improve a lot stopping down the aperture
Included 72mm lens cap is junk
Hood not positive feeling
Focusing at 85mm f/1.4 is difficult
About 1/3rd stop darker than my other 85mm lenses
Bottom Line:
Buy this lens now if you want a superb manual focus long portrait lens of modern design and don't want to empty your pocket book. It performs like a name brand 85mm f/1.4 at a fraction the price. You must be proficient with manual focus to use this lens at f/1.4 (or be willing to learn).
Review:
The lens produces nice usable portraits from wide open. There is a pleasing softness too it, but the eyes appear nice and sharp and the bokeh transitions are smooth. Specular highlights in the bokeh are smooth and fairly uniform with minimal rings or donuts. The modern aspherical lens design takes care of most spherical aberration. I bought this lens solely for f/1.4-f/5.6 usage. If I want to use the f/4+ range I will use my f/4 zoom, so wide open performance of the 85mm was critical too me, otherwise it added nothing over my slower zoom. I would not be afraid to use this lens at f/1.4 for portraits.
Wide open it does show a small amount of purple fringing around very high contrast subjects, but it almost has to be blown out next to a darker object for it to be noticeable. The lens also has your typical green/red chromatic aberrations (CA) visible in the bokeh, which I think is longitudinal CA. This is actually fairly typical of large aperture lenses, even good lenses. It is generally not intrusive. The lens is also a tad darker than my other 85mm lenses, maybe 1/3rd f/stop.
Focus is critical at 85mm f/1.4 as the depth of field is shallow, and most dSLR focus screens are designed to focus for f/4. I think the one in my K-7 is a bit better but still doesn't show the true DOF at f/1.4, so it is impossible to focus totally precisely less than f/2 or so, but with practice you can get really close. Also, for slower subjects live view is useful. The focus feel of the lens is excellent with a heavily weighted focus ring that feels high quality.
Lens construction is equivalent to any Canon L lens or Pentax DA*. It is a metal body at the base with a quality feeling plastic focus ring/upper body (this feels like the Plastic in DA* or Canon L lenses). The only part that feels cheap is the rear lens cap, the front lens cap, and the hood. At least they only cut costs with the non-critical items.
This will make an excellent manual focus video lens too, because of the pleasing bokeh wide open and the shallow depth of field. This is one of the reasons I wanted the good bokeh wide open.
Overall, this is a great lens for a superb price. The maker is Samyang, but it is sold under the Vivitar, Opteka, Bower, Rokinon, Polar, and other names. Image quality is supposedly the same between any make, but accessories might differ depending on what the brand wants to include with the lens. The Vivitar Series 1 lens has a slightly different look to it.
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