[Alberts]

Hi, everyone!

I am from Riga (Latvia). I bought a new Pentax DSLR K-x at the beginning of 2011. It is my first DSLR camera and second digital camera. I bought the camera equipped with two standard kit DA lenses - 18-55 mm and 50-200 mm. I am quite satisfied with the camera. I use it in short trips quite frequently, mainly, to photograph landscapes or portrait+landscape (so-called travel photo). Sometimes I photograph the moon.
However, I sometimes luck the telephoto feature above 300 mm (35 film equivalent). I previously used point-and –shot camera Olympus SP-500 UZ that allowed optical zoom up to 350 mm (35 film equivalent). The standard DA lens 50-200 mm allows me to reach 300 mm (35 film equivalent). Sometimes, for example shooting the full moon, I want a little more than 300 mm. At the same I am not a professional photographer or very passionate amateur. So I have been looking for some cheap lens provides focal length above 300 mm (35 film equivalent). Recently I found out about a lens SMC Pentax-FA 100-300mm F4.7-5.8. This lens offers focal length up to approximately 450 mm (35 film equivalent). According to reviews in this forum, this lens is both quite cheap and good (for amateurs). And it seems to be fully compatible to Pentax K-x body. So I am considering buying this lens if I find a good offer on-line.
According the user’s manual of K-x, this lens should fit K-x, the AF, Auto aperture and P, Tv, A, M modes should work, etc. However, I am not very well-informed in technical details of lens, lens mounts and so on. So I am little hesitating and have some concerns about this lens compatibly to my camera (this lens is from film era). I will highly appreciate advice of more experienced users.

Faithfully,
Alberts

[Tranzistors]

Hello! I am another Latvian Pentax shooter with K-x form 2011 purchase.
For cheap and long lenses you should consider Mirror "lenses", like ::: Samyang Optics co., ltd. - We bring you Safety :::
On e-bay they come for about 100 LVL (last time I checked). You will need T mount to K mount adapted though. They have problems:
* no auto focus
* fixed aperture
* perhaps ugly bokeh (irrelevant for moon and stars)

Good things:
* light
* no chromatic aberration (helps for moon photography).

[Jüri]

Greetings from Estonia!

I advise you not to worry too much about the long focal length. Once you find out how pointless taking those moon-shots is, you'll undestand that 300mm is more than enough. I hardly ever use anything above 75mm.

[Alberts]

I would like to specify that at the moment I have DA L kit lenses not DA lenses. DA L is not the same as DA .

[Alberts]

I agree that usually there is no need for focal length above 75 mm. In most cases I use the standard kit lens DA L 18-55 mm. The second lens – DA L 50-200 mm is used by me quite rarely. However, I have some fashion to shoot distant objects like the moon. Sometimes I would like to shoot animals, birds and similar objects that also require longer focal length. I understand that potential third lens with focal length above 300 mm will be used quite rarely. It will surely not be my basic lens. So I am seeking some cheap not perfect lens but quite functional lens (that supports my K-x more or less fully).

[snappychappy]

The Pentax 55-300mm is an excellent lens and is relatively cheap second hand.

[Alberts]

I presume that Pentax 55-300 mm is good. However, I have already got DA L 50-200 mm. And the price of DA L 55-300 mm seems to be even higher than for a second hand SMC Pentax-FA 100-300mm F4.7-5.8. So I am more thinking of hand SMC Pentax-FA 100-300mm F4.7-5.8. However, my reasoning might be incorrect.