Saturday, February 12, 2011

Pentax FA* 300mm f/4.5 review

Build quality / Handling

Pentax Fa* 300mm f/4.5
© Quiet Leaf

From the professional grade lenses of Pentax back in the 90’s, this lens is built like a tank. It’s solid, heavy (935g) and seems ready to take years of abuse. The front element is recessed for 1cm into the lens body and doesn’t protrude at all, keeping it safe from any direct hit when the lens hood isn’t on.

The aperture ring is made of plastic and goes from f/4.5 to f/32, the focus ring has a push/pull mechanism to control the focus. Note that if you want to set it on manual, you must change it from the lens, the switch on the body isn’t enough on its own.

FA* 300mm f/4.5 and Canon 70-200 L f/4
© Quiet Leaf

The lens came without lens hood, and I was a little bit worried by the lack of a proper flare protection but after several hundred shots under bright and direct light right into the lens, the need of one rapidly vanished as the lens doesn’t suffer at all from ghosting or flaring. I used to screw a rubber shade on it but it was more in order to protect the lens when I had to put it on a rough surface.

Be careful, even if it’s a FA*, the lens IS NOT weathersealed!
But fortunately it can be easily taped (albeit you lose the manual focus option).

Pentax FA* 300mm f/4.5 and Canon EF 70-200 L f/4

The lens is sufficiently small to be carried around without too much last; it has a filter thread of 67mm (compared to the DA* 300mm f/4 which is 77mm) and measures 16 cm long. It can be put in a regular shoulder bag when mounted on a camera + grip, and taken in and out without too much hassle. Since it’s so small for a 300mm and with a silver coating, it doesn’t attract attention compared to the grayish Canon 300mm L counterpart (16 cm vs 21,3 cm).


As usual, the autofocus mechanism is on the noisy side, you don’t have the speed nor the quietness of a SDM / USM motor. But you can be sure that it will never let you down – screwdrives lasts forever!

For static and slow moving objects under good light conditions, the autofocus is quick and precise; but when it comes to fast actions e.g. football players or rally cars, it tends to be a tad too slow to catch the right speed in order to freeze in focus the spot that you want. In 60% of the situations, the picture will have a slight blur due to this delay (estimated number after lots of open air sports shooting)... But we’re talking about fast and unpredictable movements, so for most users it won’t be an issue here. Wildlife and lifestyle photographers will be overly satisfied with this lens but sports shooters must look to other options (with SDM / HSM equivalents – or a faster autofocus system, but that’s another debate).


The lens was tested on a k20d, but results may vary with the new k5 since it has a new in-body motor and a new autofocus type.

Image quality

Wide open and with the long focal length, it delivers a decent bokeh (8-bladed diaphragm, but remember that we’re talking about an f/4.5 lens on APS-C, so it’s more like an f/5.6 bokeh) and an excellent level of detail and contrast. It’s tack sharp when stopped to f/5.6.

The 8-bladed diaphragm
© Quiet Leaf

The K-mount and the aperture ring
© Quiet Leaf

It’s one of the few lenses which I had the “wow” surprise when pixel peeping pictures at 100%. The amount of detail was absolutely stunning, on par with the FA 50mm 1.4 at f/4. With the FA* and the 14.6 mp of the k20d, I kept going deeper and deeper in the picture, I was still able to crop it and stay with an excellent picture.

Working with JPEG’s and AWB, colours were naturally saturated and contrast was very high. All in all, it’s a lens that has an excellent piqué... I was seeing here the benefits of Pentax’ Super Multi Coating, one of the company’s best strengths. No flare, no CA. A real gift for every photographer.
In the field

Mounted on a k20d with the battery grip, the lens is very well balanced for shooting handheld but lacks the tripod collar when it has to be mounted on a mono or a tripod. Several owners use the tripod collar of the Canon 70-200mm f/4 (or equivalent) without any trouble, there’s just enough space between the aperture ring and the scale window to attach it there. On its own, when the camera and not the lens is mounted on the tripod, the camera can’t handle the 935g without trouble and suffers from disturbing vibrations. You can use it handheld (but I would consider a handstrap) and at the end of the day you won’t suffer so much from the wheight (but not if you’re shooting continuously for 1 hour).   

The FA* mounted here on the k20d
© Quiet Leaf

Pentax k20d and FA* 300mm side by side
© Quiet Leaf


When I found it in a second hand shop, I didn’t realized at first how lucky I was; for the price I paid (around 600€ - used - but with the autofocus mechanism cleaned and calibrated, no other problems) this lens is a must-have for light and tough travellers. The metallic outer shell inspires so much confidence that you know that you can use the beast everywhere, it’s small enough to be carried around – we’re talking about a 300mm! – and comes with a screwdrive mechanism that will never fail, and image quality on the bests levels.

All in all, this lens is hard to find (in France/Benelux, I see sometimes one once a year on the 2nd hand market, no more) but if you can grab it, you won’t regret it.

Nearly 1kg of metal and glass, this lens is  nearly indesctructible
© Quiet Leaf

 f/4.5, ISO 400, k20d
© Quiet Leaf


  1. You can sometimes find near mint ones with the hood and without all the scratches in North America for less than what you paid.

    I know since I sold mine on eBay last year for $750. It is a very good lens, but the s-l-o-w focus is a pain.

    Still, from what I've seen from the current 300, the FA* produces better photos.

  2. Very good write-up Yann !

    I compared the FA*300 to the DA*300 just last week, on a K5. The AF on both struggles when shooting from say 30 yds (metres) down to 5 yds but the FA shades it. When making small focus adjustments (e.g. 30 yds to 25 yds) then both were fast and no advantage to either lense.

    The DA*300 though is totally silent ! Whereas the FA is a little noisier - but as a Pro friend of mine said (and I never thought of this) you can just wrap it for birding if necessary.

    The DA*300 is sharper - no doubt - but not by much and you really need to pixel peep to 1:1 to see the difference.

    A guy on Pentax Forum who has both agreed with the comments above when I asked him - and also with your comments on great contrast.

    In the end I bought the DA*300 (guarantee and WR) but I'm sure I'd have been just as happy with the FA.

    The addition of the hood (which just makes it look soooo much nicer !) takes the weight over 1kg - almost identical to the DA*300 - but both of them are easily hand-held, a huge advantage over some other brands' huge 300s.

    BTW the SDM motor is not fast, but IS virtually silent. It offers almost no speed advantage over screw-driven lenses.


  3. Yes, the SDM motor (and every equivalent) is a real gift when shooting in quiet environments, but I never heard about wrapping a lens, It can be quite difficult if you have a 60-250mm when it comes to reach the zoom ring!