Pentax 300mm f/4 ED IF SDM SMC DA*
(From Pentax lens literature) The smc Pentax DA* 300mm f/4 ED (IF) SDM (focal length equivalent to 450mm in the 35mm format) is a high performance telephoto lens featuring weather resistant and dust resistant bodies. The SDM system creates a smoother, quieter auto focus and the lens features a Quick-shift Focus System for instant switching from auto focus to manual. The Pentax SP coating protects the exposed lens elements from grease and dust.
- High performance telephoto lens
- SDM system creates smoother, quieter auto focus
- Weather resistant and dust resistant body
- Quick-shift Focus System for instant switching from auto focus to manual focus
- Pentax SP coating protects the exposed lens elements
- ED elements compensate for chromatic aberration
- Developed specifically for Pentax digital SLRs
- Focal length equivalent to 450mm in the 35mm format
Pentax 300mm f/4 ED IF SDM SMC DA* User Reviews
10 out of 10 points and recommended by sjwaldron (6 reviews)Sharp low chromatic aberration lens with quality build and WR.F4 aperture and AF speed isn't that fast.
What I like about the lens:reviewed November 24th, 2010 (purchased for $1,100)
- While I have not scientifically tested the lens, I feel that it is sharp enough from it’s widest aperture and have never found an image that was was not good enough due to optical quality.
- It follows the tradition of Pentax rendering with vivid contrast. This lens is also very strong at controlling chromatic aberrations such as purple fringing.
- Seems very good at controlling flare, but I almost always use the lens hood.
- The bokeh can be beautiful (at times), especially in combination with a sharp subject producing a strong 3D effect.
- The lens seems bright throughout the whole frame event at the widest aperture (it is a full frame lens by design and has been confirmed “good enough” on pentaxforums.com with film cameras).
- The construction is top notch and one of the best lenses I’ve personally owned.
- SDM is quiet in focusing compared to screw-drive lenses.
- Quick-shift focus with a nice feature to have.
- Topnotch weather sealing.
- Small and light for it’s abilities relative to similar lenses.
- The lens is very versatile considering how long the focal length is, which is partly due to the short minimum focusing distance.
- I can easily hand-hold this lens and pan-focus on moving subjects.
- The lens is still very sharp and usable with a 1.5x Kenko teleconverter.
What I’m not too fond of:
- Maximum aperture of f4 is challenging at times with my K-7 because I like to keep the ISO low, but I’m not sure how much having f2.8 would really help…
- The lens isn’t cheap hovering around $1100, but good lenses hold value well.
- Pentax SDM hasn’t had the best track record, but my lens has been problem free. I did have two instances when I first got the lens where I needed to slightly rotate the screwdrive screw on the camera body after seeing that the lens locked up of sorts when I tried to auto-focus. For whatever reason the screw-drive connection wasn’t complete and held up the SDM from functioning. I’m guessing the screw drive connection in the lens was just a bit stiff initially (especially since the screw-drive bit isn’t used but on the oldest of camera bodies).
- Focus isn’t “lightning fast” with the K-7 and K10D, but it works fine. I think the K-5 might be better in this regard.
- Not specific to this lens as I have not had SDM issues, but I feel Pentax should allow users to select either SDM or screw-drive focus mode in the camera body. I have a feeling the lens would be faster in screwdrive mode as well.
- Bokeh can be wavy depending on the scene and conditions, which is most likely due to having sharper more contrast-y background blur or possibly just a property of the glass elements in how they handle the light and how you are facing a close background. I always use a lens filter, so I can’t say if it’s caused by that or just a property of the lens design.
One of my best lens for sure. Although it’s also my most expensive lens to date, so quality should be high. If you are in need of a long telephoto and want to stay with Pentax and not buy a used lens, this is it. Your only other option is the 60-250mm, but I feel the DA* 300mm provides some positives to make up for not having the ability to zoom. Such as better weather resistance by not having an extending barrel, 50mm more millimeters in focal length, ideal long telephoto lens for people who prefer primes, and most likely a bit cheaper than the 60-250mm. Either lens would be a good buy though… Your other options for new lenses would probably be in the Sigma and Tamron line-ups, but those currently don’t have weather resistance, which I feel is important in these “slow-ish” long lenses that are designed for being used outside.
Photos and analysis in my blog article.
9 out of 10 points and recommended by buckeyemikie (1 reviews)Beautiful bokeh; easy to hand hold w/K10 & 20; very sharpnot inexpensive
I've used this lens for about two months now and like it better every day. I've used it on my Bushhawk shoulder mount, Bogen and Flashpoint (carbon fiber) tripods with excellent results. Watch your shutters speeds if using a shoulder mount as its easy to end up at too low a speed even with IS tunrded on. I've used it to shoot tulips using selective focus to highlight a single tulip in sharp focus with beautiful results. I also have very sharp photos of birds at my feeders (even with a 50% crop) with my K10 & 20 bodies. I hope Pentax comes out with the weather-sealed 1.4X converter as rumored. Aftermarket converters for Pentax AF are hard to find.reviewed September 6th, 2009 (purchased for $1,079)