CalArti

I’ll never forget when I bought my first SLR camera. I was working on a project making digital collages, and found that I needed to go out and take some photos to use as source material in the collages. I knew nothing about photography, but I did a little reading and wandered into the local camera shop, intending to buy an APS camera, which (based on my reading) seemed to be the obvious future of photography...

By chance I wandered over to the used equipment counter, and before all was said and done I had blown my budget and was walking out of the store with a Pentax Pz-70 camera, and a pair of Takumar-F zooms. I was elated – I was certain that I would never need to buy another piece of camera gear again...

The decision to go Pentax was purely accidental, but for me it was a happy coincidence. The basic Pentax K mount is virtually an open source design, and Pentax’s commitment to backwards computability remains strong. With a few exceptions, you can use almost any lens on any body. I used to love using the FA 43mm f1.8 limited - a very new lens - with the 20+ year old Pentax LX. Similarly, my mid 1980's Kiron 105mm macro lens works wonderfully with the *ist-D digital SLR body. Auto focus, manual focus, lenses and bodies are all interchangeable (with a couple exceptions.) This opens up a wide world of available lenses and equipment.

(Unfortunately, the interchangeability of lenses and bodies is not as complete as it was a few years ago. These days you have “D” lenses that are intended to work with digital SLRs, some newer lenses that lack aperture rings and are incompatible with some bodies. And lastly some bodies are incompatible with the very oldest Pentax lenses (though, through a rather ingenious work-around, the *ist-D digital SLR can be used with even he oldest K Mount lenses.)

For a full rundown on all aspects of Pentax gear, check out Bojidar Dimitrov's Pentax K-Mount Page.

The purpose of this essay is to share a few subjective impressions of the K Mount lenses I have personally used. Over the last few years, as I have bought and sold a variety of K-Mount lenses, I've often wished for more info regarding available lenses. So here are my thoughts regarding the lenses that I have owned and used.

As noted in the title, the following observations are primarily my subjective impressions about the lenses. From time to time I do run formal tests of my lenses, but that is usually to determine the relative quality of two or more comparable pieces. I never run formal resolution tests that determine line per millimeter data or some other objective data. There are sites that have this data - www.photodo.com being most notable - and such information can be a useful factor in evaluating lenses. But ultimately, this is more of ramble than a review.

A Few Qualifiers

Although the comments below are subjective, here are a few qualifiers that may put some in perspective.

First, it's important to note that while many lenses are discussed below, I regularly use just a handful of lenses for most of my work. Hands down, the SMC A* 200mm macro is my most used piece, and accounts for most of the close up images of insects and plants on this site. Three zoom lenses pick up most of the balance - these being the FA 20-35mm, FA 28-70mm, and Sigma 70 - 200mm. While I used to shun zooms, I've found these lenses to be excellent for landscapes and general purpose shooting. For event photography, portraits, and the odd wedding, the FA 28 - 105 and Sigma 70 - 200 are ideal choices. Aside from the above, the A* 400 f2.8, often with the F 1.7x teleconverter, is my main choice for birds and some landscape shots.

Other favorite lenses that see less use include the, Kiron 105mm macro, FA 50 f 1.7, A 50 f1.4, and the rather funky F 17 - 28 fisheye zoom.

And while these and other lenses get the occasional work out, a small number of lenses covered below have seen little use. These were mostly opportunistic eBay deals - those rare occasions where a low bid prevailed. I usually run some quick test shots with new lenses, but in some cases the lenses have been used very little, and I’ve ultimately sold off many of these lenses. I try to note these cases so you can weigh the comments on the lens appropriately.

Terminology

The terminology below should be familiar to anyone experienced with Pentax K mount lenses. For those who are not, here is a quick guide:

SMC: Super multi-coated. Pentax's patented 7 layer multi coating process. Almost all of the K Mount lenses were SMC, the Takumar-F series being the main exception.

Takumar: Probably the most confusing term in the Pentax lexicon. Originally, Takumar lenses referred to Pentax screw mount lenses. With the introduction of the super multi coating process, SMC-Takumar lenses appeared. With the subsequent introduction of the bayonet K Mount, the Takumar label was applied to budget lenses that lacked the SMC coatings. These lenses were made in both manual focus and auto focus mounts.

K Series Lenses: The earliest manual focus K mount lenses bore no series designation. They simply bore the "SMC Pentax" and "Ashai Optical Co., Japan" designation. For the sake of clarity, I have used the designation SMC-K in describing these lenses.

M Series Lenses: In the early 1980's, Pentax introduced a series of compact, manual focus, lenses designed to accompany the popular ME, ME Super, and MX cameras. These lenses bear the designation "SMC Pentax-M" along with "Ashai Optical Co., Japan."

A Series Lenses: These manual focus lenses have the contacts and aperture ring setting to support program modes - like auotexposure mode or shutter priority. When set to the "A" setting the camera body can control the aperture setting. These lens also support evaluative metering in modern camera bodies. (The K and M series lenses allow only center weighted metering.) The “A” lenses retain full compatibility with all Pentax Cameras, including the most modern digital SLR's. The prior K and M lenses are not compatible with some newer bodies.

F and FA Autofocus Lenses: Pentax has produced two series of autofocus lenses - the F and FA lines. In many cases, the differences between these two series are primarily cosmetic, with some differences in internal electronics. While some FA zooms support the power zoom function, newer FA zooms do not.

A newer variant on the FA lenses are the D-FA lenses. These are optically optimized for digital photography – with lens design and coatings that intended to reduce chromatic aberration and otherwise work well with digital SLR’s. However, the image circle covers the full 35mm frame, these lenses have aperture rings, and are therefore fully compatible with Pentax K Mount film cameras as well.

Star "*" Lenses: Pentax designates their highest quality lenses with a green star - usually transcribed with the asterisk. M*, A*, F*, and FA* lenses all incorporate ED elements, and in many cases incorporate internal focusing (EDIF).

I describe non Pentax K Mount lenses as follows:

K-compatible: Manual focus lenses that do not support autoexposure features.

A-compatible: Manual focus lenses with auto exposure support.

Autofocus: Third party lenses comparable to Pentax F or FA lenses.

Note about Ricoh lens compatability:

Ricoh program lenses are not compatible with Pentax Auto-Focus bodies. You can identify these lenses by a “P” on the aperture ring – when the ring is rotated into the “P” (Program) position, it locks in place and you have to depress a small button to get the aperture ring to move again.

The Ricoh program lenses have a small ball bearing contact on the rear flange of the lens that will pop right into the hole that holds the AF cam on Pentax autofocus bodies. The result will be that the lens gets locked tight on the body, only halfway mounted. I learned this the hard way trying to mount a Ricoh lens on my Pz-1p! It took a trip to the repair shop to get the lens off the camera.

The Ricoh program lenses will work fine on manual focus Pentax bodies – no AF cam or hole to get stuck on. With my Ricoh 50mm f 1.7 I just removed the back flange from the lens and took out the ball bearing contact. With the modification it no longer works as a program lens on Ricoh bodies (not that I have any Ricoh program bodies) but it is now compatible with Pentax AF bodies.

Older, non program Ricoh lenses do not have the contact or this problem These lenses are basically like SMC-M or K lenses in their aperture operation.

With the exception of the 50mm f1.7 mentioned above, all of the Ricoh lenses reviewed here are the older, non-program models, that fit without problem on all Pentax bodies, both manual and auto focus.

And with that - here are the lens summaries:

Prime Lenses

Sigma 14mm f3.5 (A-Compatible): In brief - very wide, flawlessly rectilinear, and reasonably priced. This is not a lens that I use very often, but when I do the results are usually good. The ultra wide angle of view opens up many interesting creative opportunities. The lens is very sharp, suffers form light fall off at aperture below f8, and does have a problem with flare / reflections when bright light sources hit the front element. The are not uncommon problems for lenses of this focal length. For me, this is a nice optic in a focal length that I don’t use very often, and was available at a reasonable price. I have the manual focus version of this lens, and keep it in my bag, despite infrequent use. This lens was replaced by Sigma's 14mm f2.8 EX Sample photos - 1, 2, 3.

SMC-K 24mm f2.8: Much sought after and often pricey, I used this lens only a few times before selling it. The few shots I took with it looked very good, but the FA 20-35 f4 looked just as good, so I decided to hang onto the zoom and sell off the prime.

Ricoh XR Rikenon 24mm f 2.8 (K Compatible): Adequately sharp but somewhat weak in flare control, this lens nonetheless is very reasonably priced, features an outstanding build quality, and is an excellent way to get into a prime at this focal length. As with the 24mm SMC-K, I sold it off in favor of the FA 20-35 f4.

Ricoh XR Rikenon 28mm f2.8 (K Compatible): This is one manual focus lens I still use a lot. Its a standard for my infrared film shooting. I’m very satisfied with the results of this lens. Not a common lens, it can be had at a reasonable price when you do find it. Sample photo.

SMC-A 35mm f2.8: The most disappointing Pentax lens I ever tried. Unsharp at any aperture, this lens just never produced good results. Not recommended.

SMC-K 35mm f3.5: I bought this as a replacement for the SMC-A 35mm f2.8 and was happy with the results. Again – sold it off when I got the FA 20-35.

SMC-M 40mm f2.8 Pancake: Many people find the diminutive size and nearly perfectly "normal" focal length to be very compelling, and this lens regularly sells for a pretty high price on eBay and other venues. Personally, I'm not enthralled by this piece. Granted, the 40mm focal length is great - the perspective is more relaxed than 50mm and does not have quite the wide angle feel of a 35mm. But this small size makes this lens a pain to work with, the optical quality is good but not outstanding, and the price is ridiculously inflated. If you like small things or if you can get this lens at a discount, it just may be right for you, otherwise you can get better optical performance and a fraction of the price from an SMC-M or A 50mm f1.7. While the 50mm is over twice the size of the 40mm, it still is only about 1 CM longer - so with a little ingenuity you can probably still be able to carry the more bulky 50mm setup.

SMC-FA 43mm f1.8 Limited: A really outstanding lens - exceptional build quality and style, with really impressive optics. The price is a bit daunting though. As much as I liked this lens, I ultimately sold it off. The most compelling reason for me to use this lens was the focal length, but as I moved to the digital *ist-D with it’s 1.5x focal length factor, the 43mm lens became an effective 65mm – not nearly as compelling. Sample photo.

SMC-A 50mm f1.4: A fine normal focal length lens, very sharp, great flare control, and excellent color rendition and contrast. In the "bang for the buck" category this is near the top - a truly great optic typically available used for under $100. I tested this lens against the Ricoh Rikenon 50mm f1.4 and very rare Rikenon 55mm f1.2 - and it outperformed both. Sample photos 1,2.

Ricoh Rikenon 50mm f1.4 (K Compatible): Not particularly sharp and with pretty poor flare control, this lens does have some interesting characteristics. I shot quite a bit with this for a while, but it was supplanted by better 50mm lenses. While it makes pleasing images with a nice bokeh, there are better choices in the 50mm range. Sample photo.

SMC-M 50mm f1.7 / SMC-FA 50mm f1.7: I'm lumping these together since they are virtually identical optically (the most notable exception being in the lens coatings.) These lenses are very sharp, with excellent flare control. Folks who love minutiae love to debate over the pros and cons of the 50mm f1.4 and 50mm f1.7. From my perspective the optical differences are so slight as to be meaningless. However, the manual focus M 50 f1.7, which often sells used for $20 -$30, certainly is a great buy. I use the FA 50 f1.7 when shooting film with an AF body, and the A 50 f1.4 when shooting with a manual focus body. This lens also performs very well on the *ist-D digital SLR, thought the effective 75mm focal length is not ideal.

Ricoh Rikenon 50mm f1.7 (K Compatible): I bought a newer version of this lens on sale, and used it on a camera that I kept under the car seat for a few years. The all plastic construction of the newer lens is a bit disappointing, the optical performance is very good but not on par with the Pentax 1.7.

SMC-M 50mm f2: I use a pair of these lenses as loupes for examine slides, but have never put them on a camera to test them out.

Ricoh XR Rikenon 50mm f2 (K Compatible): This is rumored to be one of the sharpest lenses ever made for 35mm cameras. I bought an old, clunky, all metal version of this lens for $10 on eBay. I have yet to test it out.

Sigma EX 50mm f2.8 macro (Autofocus compatible): Pretty big and bulky for a 50mm, this lens focuses down to 1:1 without any additional extension or filters. I use this lens mostly for snow crystal shots, and it has performed admirably in that capacity.

Very sharp, but also rather slow, This lens only focuses down to half life sized - you need to added extension tubes or close-up filter to get additional magnification. Its a nice lens and pretty inexpensive as macro's go, but if you want a macro lens for close focusing, one that focuses down to 1:1 would be much better. If macro focusing is not important, a faster, cheaper, smaller non-macro 50mm is a better choice. I mostly use this for shooting snow crystals, though in the last year the aperture blades have gotten sticky (especially in sub freezing temps) so it has been supplanted by the Sigma 50mm f2.8 for that use.

Ricoh XR Rikenon 55mm f1.2 (K Compatible): A big, fast lens that comes close to the Pentax SMC f1.4 and 1.7 50mm's in quality. I like the size and heft of this lens, and the mystique of a lens this fast is really appealing. But in my tests I found that the SMC 50mm f1.4 was sharper at f 1.4 though f4, at which point the performance of the two lenses seemed to be equivalent. This is a fine optic, but more of a collectable than a working lens, IMO – which is why I sold mine to a collector. Sample Photos 1, 2, 3.

SMC-M 100mm f2.8: Great lens, Small, great optics, and available at a reasonable price. This is a nice lens for portrait work or general shooting - much smaller than a 100mm macro and with a focusing mechanism that allows you to fine tune distant subjects as opposed to close ones.

Kiron 105mm f2.8 macro: A big macro lens that focuses down to 1:1, this was my main workhorse lens before I bought the SMC-A* 200 macro. There are a lot of macros in the 90-100 mm focal length, and many are very good. This is one of the best and is great if you can get it at a reasonable price. I use this on the digital *ist-D, also with good result. There is some very slight chromatic aberration apparent when using this on the digital, but nothing beyond the ability of Photoshop’s raw interpreter to correct. Update: Once I started using this lens on the K10D, I noticed pretty significant chromatic aberration, particularly at high magnification shots. It is still manageable in Photoshop, but prompted me to upgrade to the DA 100 f 2.8.

Sample Photo 1, 2, 3, 4.

SMC D FA 100mm f2.8: As noted above, I upgraded to this lens, in part to get past the chromatic aberrations of the Kiron 105mm macro, but also to gain autofocus in a macro lens. This lens is much smaller and lighter than the Kiron, however it lacks the rugged metal construction of the older lens. Autofocus can be relatively fast – but the lens lacks a focus limiter so if the camera does decide to start hunting, the lens can annoying swing far out of focus. The manual focus ring is large, and the focusing mechanism is smooth. This lens also employs the clutch focusing mechanism, so you can manually focus at any time without disengaging autofocus on the body. The lens also features a focusing clamp, which will lock the focus position in place – handy when working in a studio environment.

This lens has a really huge hood, which attaches to the main body of the lens, and not the front element. This means that as the front element extends – and as you focus down to 1:1 it extends by a couple of inches – the hood does not move. However, at high magnifications the front of the lens is almost flush with the edge of the lens hood, making the hood essentially ineffective. Personally, I don’t like the design and have opted to just put a hard, 49mm threaded hood onto the front element (by chance I have a sturdy metal one that works very nicely.)

From my limited use of the lens thus far, image quality appears to be superb. I intentionally shot high contrast scenes, hoping to induce chromatic aberrations or fringing, but virtually none was to be found. Resolution, detail, edge definition are all excellent. Color saturation, contrast, and flare control are all excellent. Tested on a film body (Pentax Mz-S) the lens proved that it did indeed cover the full 35mm frame, even at 1:1 magnification, with no noticeable light falloff in the corners.

Overall – I’d highly recommend this lens to anyone seeking a 100mm macro. Someday, when I get over my emotional attachment, I might even sell my Kiron, which seems to be doomed to get even less use than before.

Sample photo: 1.

Bayonet Takumar 135mm f2.5: Generally regarded as a dog, this lens lacks the Pentax SMC coatings. While the build quality is nice, the multi colored aperture markings make it look somewhat cheap. And this is a cheap lens - usually retailing below $50 US. But for all it's faults, I always have fun with this lens. The finder is really bright for a telephoto, the shallow depth of field wide open is great, and while it's not the sharpest optic it does a decent job in most situations. If you find one priced cheap, grab it and join the fun.

Pentax SMC A* 200mm f2.8: A truly fine lens in every respect. Sharp, well build, fine Bokeh, impressive speed. Like many A* lenses it can be expensive, but is worth it. Ultimately, I sold mine off – at one point in time I had two zooms that covered 200mm and three prime lenses at this focal length. I whittled that down to the pair of zooms and the following lens:

Pentax SMC A* 200mm f4 macro: My most used lens - rock solid in build quality, exceptional optics and sharpness. This lens focuses down to 1:1, at which magnification the size of the image projected onto the film is the same as the size of the subject . I use this as my primary lens for both field and studio macros. This lens is compatible with the excellent 1.4x - L and 2x - L teleconverters - and in combination with those you can achieve some really high magnification images. This has continued to be my #1 most used lens for macro work with the A*ist-D, and the results are truly excellent. Highly recommended. Sample photos (most of the insect and butterfly galleries.)

SMC M 200mm f4: Compact, well built, with very good optics. This is an affordable 200mm, not in the league of the A* lenses noted above, but also costing only a fraction as much. I use this lens with a 50mm reverse mounted in front as an easy way to get 4x life sized macros, and it does well in this application.

SMC A* 300mm f4: Quite small and compact for a 300mm, excellent optics but not quite at the level of the A* 200's. My only complaint about this lens is the minimum focusing distance - just under 3 meters - which can limit it's usefulness with small subjects. Despite this quibble, this is an excellent lens. This lens also works well on the *ist-d, where, due to the focal length factor, it is the equivalent of a 450mm f4 – a much more useful focal length for telephoto subjects. Despite this – its one of the least used lenses in the bag. Sample Photos: 1, 2.

SMC A* 400mm f2.8: Big, fast, and heavy - I use this lens for birds, landscapes, and the occasional close up. I almost always use this lens with teleconverters - typically the 1.7 F autofocus adapter, but also with the 1.4x-L adapter and 2x adapter. With the 1.7x adapter, this lens becomes the equivalent of a 640mm f4.5 on a 35mm camera, and the equivalent of a 960mm f 4.5 on the *ist-D. While the autofocus aspects of the adapter are limited with this lens, AF does kick in once the lens is pre-focused. Sharpness is on par with the best of the Pentax A* lenses. The only complaint I have with this lens is that the Bokeh can be harsh, particularly when used with the 2x-L teleconverter. Sample photos (no teleconverter): 1, 2, 3. Sample photos (with 1.7x teleconverter) 1, 2, 3.

Tokina 400mm f 5.6: Like most Tokina lenses, this is a well build, solid piece. It's fairly small and compact for a lens of this focal length. Optical quality is acceptable at f5.6, much better at f 8 and 11, though it never rises to the level of the Pentax A* lenses. On he *ist-D this lens become the equivalent of a 600mm lens on a 35mm camera – making it very usable for birds etc. Sample photo.

Takumar 500mm f4.5: Often refereed to as "Battle Ship Takumar," this lens is big, heavy, and all metal. My copy was the oldest, single coated screw mount version that was crudely modified to be a K-Mount lens by having a K mount adapter permanently affixed to it.. It was also make in a SMC screwmount version, and a K-Mount version. The K Mount version, which incorporated the same optical design, was manufactured through the late 1990's. With a manual aperture, physical size close to its focal length, and minimum focusing distance of 10 meters, this is definitely not a modern optic. But that does not prevent it from delivering great images. In terms of sharpness, my tests show this lens to be on par with the Tokina 400mm f5.6 - very good but not outstanding. Where this lens is really outstanding is in it's saturation and contrast. Looking through this lens there is a visible 'pop' to colors that you can see in the finder - and that shows on the film as well. The screwmount version can found at very reasonable prices - mine cost $430 - and are probably the best way to get into some serious 'big glass' at a reasonable price. Though I sold my Takumar off before going digital, I suspect that the chromatic aberrations in this lens (even visible to some degree in film shots) would really impair its performance on a digital SLR. But – that’s speculation on my part. Sample photos 1, 2, 3.

Zoom Lenses

Purists dis them, but using a zoom may be the best way to get the shot you want. The ability to quickly frame up the shot by changing focal length means you get more shots. Though zooms often lag behind fixed focal length lenses in terms of image quality - the shot you get is always better than the shot you miss. Here's a rundown on the zoom lenses I've tried:

SMC DA 16-45 f4: It took the Pentax K10D to get me serious about the APS-C format. Up till then I was reluctant to buy any of the DA lenses, because I figured they would be incompatible with film shooting, and ultimately incompatible with a full frame digital SLR. But now that my 35mm film shooting is virtually nill, and the APS-C format seems to be here to stay, I’m finally willing to invest in these lenses. Besides – the DA 18-55mm kit lens that came with the K10D made me miss having a wide angle lens.

The DA 16-45mm lens is a notable step up from the 18-55mm zoom. The constant aperture (f4 at the widest) is nice. Overall sharpness is excellent, both in the center and the edges of the frame. There is no noticeable light fall off in the corners. The zoom range is very useful – corresponding to a 24-70mm lens in 35mm terms – though it would be nice if it were a little longer. Close focusing and maximum magnification are OK, but not as nice as the 18-55mm. Flare is very well controlled throughout the zoom range.

Physically, the lens is fairly large, but light and easy to carry. The accompanying hood is a nice accessory.

This is a fine general purpose zoom, and is the lens I usually keep on the K10D. What’s not to like? The lens displays slight chromatic aberration in high contrast scenes – like tree branches against a light sky. Not enough to be a major problem.

Pentax SMC-F 17-28 fisheye zoom: Now here's an odd duck. At the widest setting this lens has a pronounced fisheye effect, but as you zoom in the fisheye effect becomes less pronounced until it all but disappears. At the 28mm setting, this lens shows very little fisheye distortion, but shows a wider angle of view than a typical 28mm - approximately that of a 24mm. One drawback of this lens is that it cannot take fromt mounted filters due to a concave front element - there is a holder for geltain filters on the rear of the lens. This is a great lens that offers a lot of creative opportunity - and it's a lens unique to Pentax. Highly recommended for use with film cameras. The situation changes somewhate with the *-ist-D Digital camera. Because the digital sensor crops out the edges of the frame - where the fisheye effect is most pronounced - you don't get much of a fisheye feel to this lens on the digital SLR. Instead, you get what looks like a pretty poorly dorrected, high distortion, wide angle. It is wide, and if you can correct the barrel distortion in Photoshop this lens may be a good wide angle alternative for the *ist-D. Sample Photos 1, 2, 3, and the photo of the room here.

DA 18-55mm f3.5-5.6: This is an inexpensive ‘normal zoom’ for Pentax digital SLR’s. The “DA” designation indicates that the lens covers only the area of the APS sized sensors in Pentax digital SLR bodies, and would probably produce vignetting if used on a film body (something I have to try!) For being such an inexpensive lens (mine came with a Pentax K10D kit for an added price of well under $100) this is a very good lens. It’s not up to the most rigorous standards – wide open it is soft in the corners of the frame, shows noticeable light falloff, and is subject to pretty noticeable chromatic aberration. The image quality improves notably when it is stopped down. It also focuses extremely close for a standard zoom – verging on macro lens magnifications – which is a real boon for those of us who like to get close. I plan to upgrade to the 16-45 or some other high quality normal zoom (at 4-5 times the cost of the DA 18-55!) but for everyday shooting, this lens is more than adequate. I’ve also produced one exhibition print from an exposure taken with this lens - this shot – and while some of the defects are apparent when the image is viewed at actual pixels on the computer screen, the print itself looks extremely good.

Vivitar Series 1 19 - 35mm (A Compatible): A great lens at the price, this zoom is sharp and contrasty through its range. The one problem is flare. I used this on one trip - many indoor shots were great as were outdoor shots where the sun was behind me. But catch a few sun rays on the front element and you'd swear that Captain Kirk is beaming into your shot. A good lens if you are on a budget, not the best of class. Sample Photo.

Pentax SMC-FA 20-35mm f4: This is one of my favorite lenses and gets a lot of use. The 20-35mm focal length is a lot more useful when shooting film, but is still useful with the *ist-D. Images are sharp and contrasty, with minimal distortion. Like many ultra wide angles, this lens is prone to flare, though the accompanying hood is pretty good at helping to control it. An excellent lens all around and one that I’m sure to always take with me. I wound up selling off my SMC-M 24mm f2.8 in favor of this lens. Sample photos 1, 2, 3.

Pentax SMC FA 28-70mm f4 AL: This is another standard lens, and one that I use frequently. Excellent performance throughout the zoom range, and a good performer on both film and digital bodies. It should be noted that this is one lens that gets very mixed reviews – some people love it, others hate it. Maybe there is a lot of variation between individual lenses – I don’t know. But I do know that this lens is one of my favorites, and has produced many excellent images. Sample image: 1, 2.

Takumar F 28-80: The autofocus Takumar lenese are Pentax's 'budget' line (not to be confused with the older, screwmount Takumars, which were first rate lenese.) One of the first lenses I bought, and frankly one of the worst. Soft, unsharp, prone to flare. It had a macro setting at the long end that did provide for fairly close focusing, but the sharpness was lacking. Not recommended.

Rikenon 28-100mm f4: An old style, manual focus, constant aperture zoom. Probably set a record for the lens I owned the shortest period of time. I bought one on eBay, tested it, sold it within a week. It was sharp enough, seemed prone to flare, but had terrible barrel and pincushion distortion at the different ends of the zoom range. When you can see the distortion in the finder – time to fine a new lens.

Pentax SMC FA 28-105mm f4-56: This is the only power zoom lens that I have every used, The power zoom features were big in the Pz series of Pentax bodies, though I have never used them. The lens itself is very good, though in my opinion not up to the standards of the FA 28-70. The variable aperture is not a major problem, but is a bit of an annoyance. Optical quality is very good, but some distortion is apparent in larger prints shot at the wide angle end of the zoom. Sample photo.

Pentax SMC A 28-135mm f4: A real classic zoom that was no doubt a gem of a lens in it’s day. These can be hard to find and usually fetch a decent price. I found this to be a good sharp lens – not on par with the best primes or even the more modern zooms though. It’s solid as a rock (metal construction) and weighs about as much as a rock as well. It features a macro function on the short end – so you can focus close with the lens set to 28mm, not very logical IMO. I used mine on the trip to Skanee, and got a lot of excellent photos with it – but sold it off shortly thereafter. Sample images 1, 2, 3.

Sigma EX 70-200mm f2.8: Not as sharp as the best prime lenses in this focal length (e.g the A* 200 f4 macro or A* 200 f2.8) – but still very good. I use this with lighthouse photos, sports events, and various people shots. One quibble – it malfunctions at very cold temperatures (e.g. around 0 Fahrenheit) – the aperture opens up and does not shut. Sample photos: 1, 2, 3.

Pentax Takumar F 70-200 f4-5.6: Despite being a budget lens, my sample of this optic was excellent. I sold it when I bought the FA 80-320, but wish I still had it.

Vivitar Series 1 70-210mm f3.5 macro zoom: This lens was a bit revolutionary when it was introduced in the mid 1970’s. Apparently, it was one of the first third party lenses to be introduced that offered a quality that rivaled that of the major brand name optics. Several version of this lens were made – I had the first version, with the 67mm filter size. A lot of people rave about this lens, and it still enjoys a good reputation. Maybe I had a bad sample – you never know when you buy something used – but I found it to be lack luster in performance. Images were adequately sharp at f 8 and f 11, but were soft at more open apertures and downright soft wide open (aft f 3.5). The macro feature was intriguing – the lens snaps into a macro setting and focuses down to half life sized. On my lens, at least, the picture quality in macro mode was poor – about on par with using a single element close up filter. Again, maybe I had a bad sample – a lot of folks swear by this lens – and maybe it was quite the item 30 years ago. But personally, I would not recommend it.

Pentax SMC FA 80-320mm f4-56: This is one lens that I bought, never used much, but have not sold. I like it – very lightweight and with a good telephoto range. Performance from 80-200 is very good, more or less on par with the Sigma noted above, but of course a stop or more slower. Quality softens a bit beyond 300. Sample photo.

Tokina ATX 100-300mm f4: A massive, manual focus, constant aperture, ‘one touch’ zoom. Built like a rock – very solid. Optical performance is good, but not outstanding.

Teleconverters

Teleconverters fall into a unique category. Since they can only be used in combination with another lens, its difficult to evaluate them on their on merits. In my experience, a teleconverter that works well with one lens, may perform poorly on with another. Ultimately, using teleconverters is a bit hit and miss.

In theory, one way to avoid that kind of uncertainty is to use lenses and teleconverters that are designed to work together. Pentax makes several K Mount teleconverters that are specifically designed to work with certain lenses.

Among the current teleconverters, and the most pricey, are the 2x-L, 1.4x-L, 2x-S, and 1.4x-S series. The “L” series stand for long lens, and are designed to work with longer optics. The “S” stands for short lens.

Despite these designations, some converters are designed to be used with specific lenses. For example, the “L” teleconverters are designed to be used with the A* 200mm macro, while the “S” converters are designed for use with the A* 200mm f 2.8 (non macro.) The “L” series converters are the least flexible in terms of use. They have an extension that reaches up into the lenses that they are paired to work with. This enables them to integrate into the lens nicely, but also make it impossible to mount them on any lenses other than those they are designed to work with.

Both the “S” and “L” teleconverters have the electrical contacts needed to preserve full auto exposure features with Pentax cameras. However, there is no linkage for the autofocus drive shaft, so while these converters can be used with autofocus lenses, you loose autofocus functions when using them.

A real odd duck in the Pentax teleconverter lineup is the 1.7x-AF converter. This converter links to the camera’s autofocus mechanism, and focuses by moving the elements in the teleconverter itself, as opposed to the lens.

When I bought an A* 400 f2.8 for birding, I also bought the matching 2x-L and 1.4x-L teleconverters. Here’s my impressions of those (and other) K mount teleconverters that I’ve used:

Pentax SMC 2x-L converter: This is a fairly large converter, and is compatable with several long focal length lenses. Its expensive, and to be honest I’ve never been very impressed by its performance. Images loose a fair degree of sharpness, contrast, and saturation, but even worse is the horrific bokeh that this teleconverter and the A* 400 can produce. I keep it as 'part of the set' for the A* 400 f2.8, but in my opinion the AF 1.7x produces a much better image at almost the same degree of magnification, and the Kiron MC-7 is also also better.

Pentax SMC 1.4x-L converter: In stark contrast to the 2x-L, I can hardly tell the difference between shots taken with this converter on and without it. It is particularly useful on the 200mm macro for getting 1.4x life-sized images, with virtually no degradation of image quality.

Pentax SMC 1.7x AF converter: Like I said, this is truly a unique offering from Pentax. The optical quality is excellent – this is more or less permanently affixed to my A* 400 f.2.8 for birding (resulting in an effective 680mm f 4.5 lens for 35mm film, and a comparable 1020 mm on the *ist-D, due to the digital 'crp factor.'). The autofocus, functionality is surprisingly good – best with fast, shorter focal length lenses (e.g. a 50mm f 1.4). The effective range of the AF is limited with longer lenses, but is accurate and effective still.

Pentax K mount 2x TC6 teleconverter: This is an old, 6 element converter that lacks the contacts needed for auto features. My sample was a pretty poor performer – tack sharp in the center (and only the center) but with progressively worse distortion towards the edges of the frame.

A surprisingly good third party converter, works very well with the Kiron 105mm macro, but also as a general purpose converter. I had both the K Mount version (no electrical contacts) and the A compatible version, which supports full contacts. Both worked very well.

I have a few more lenses to add to this someday – and maybe someday I’ll buy a few new optics that can be added. In the meantime, for more scientific testing, consult sites like photodo.com.