Question & Answer

Q&A: Help me find a quality normal prime lens?

Already another question and answer post! Keep them coming. 🙂 Sharing information is a great way for everyone to learn. Edit: I have to say, I like the way he thinks. Why waste money on an inferior lens if you will eventually replace it? Opting to start with that 50-135mm f2.8 lens was a good idea. I’d say, If you have the cash, it is often a good idea to truly consider the high quality equipment for your given system of choice. On the other hand, the most expensive lens isn’t always the best. In my response, I go over some issues I see with the 31mm lens, but it is still one of the best lenses out there.

The initial contact:

I bumped into you on Youtube, have been following your channel for a while now. Great stuff!

I’m in dire need for some advice, and I have a hunch I came to the right place. I recently got into photography and bought a k-5 and a DA 50-135mm. That’s my only lens (I spent my last buck on it:P, and I’m loving it) so now I am looking for something wider. I really badly need a normal prime (something around 35mm).

Since I have little experience both with lenses and photography in general I tend to follow a simple rule: the more expensive the better. So I keep returning to the FA 31mm 1.8. I know it sound snobbish for a hobbyist to go for such a classy lens, but I wouldn’t mind the expense if deep down I knew it is worth it and simply if I enjoyed it to the last of the 1000$. Truth be told I am looking for a normal prime that would be my main lens that I can grow to love and wouldn’t get it off my camera – in which case it really can’t be too expensive. On the other hand, if I’m paying for the metal casing and sexy look it’s a huge waste. Are there other lenses that I can get away with cheaper? I don’t mind it being manual focus, I just want it to be above average in IQ and fast (at least f2, but probably even faster). What about the FA 35mm f2 AL? Or if you know of any respected old lenses that I can buy used. Are there current Carl Zeiss lenses for K mount?
What about the new crop sensor ones?

I plan to do some industrial photography so I need it to be decently sharp.

It is clear that the price for each lens is justified to a certain extent. The problem is I don’t EXACTLY know what I would be getting/loosing for the extra $. I want a lens that I won’t be needing to upgrade in a year or two, because in that case 150$ would be more expensive that a 1000$. I guess, simply put, I need a “lovable lens”.


P.s. If the price is right, I don’t mind not having AF.

My response:

I probably can give you more to think about at least.

The Zeiss lens are very expensive. There is a Zeiss 28mm f2 lens, but it’s a good $250 more expensive than the 31mm Pentax lens. I have not used Zeiss lenses, so I can’t comment on them. They are well regarded though.
The Sigma 30mm f1.4 probably would not be a good option because reviews say the corners are not very sharp throughout most of the aperture range.

I like my 31mm lens, but it isn’t perfect. For some reason, my 31mm lens is currently front focusing on my K-5 (I recently did a small photoshoot and noticed it, switched to live-view for focusing and it was perfect). So lately I have been using it in live-view mode as I have not spent the time to try and adjust the focus correction function in the camera. The 31mm is my go-to lens for videos. It’s wide enough for most situations, but not too wide, and of course the resulting quality is good. Another few negative things are the lens hood is integrated into the lens itself (designed for full-frame) and it doesn’t have quick-shift functionality (the 31mm was made before they released that feature).

I wrote an article comparing the kit lens at around 31mm to the FA 31mm:

I also have a review I wrote up on the 31mm as well:

It certainly is a good lens, but like anything it isn’t perfect and I do see some things I’d like Pentax to change with a revision.

There is the Pentax FA35mm f2 lens. There are some used ones right now on for around $430. The DA 35mm f2.4 is said to be a child of this design. I think either one is a good option, but I personally don’t know if they are as sharp and contrasty as the 31mm lens because I’ve never used them.

Then we have the FA* 24mm f2 lens. Some people think it is great, others not so much. You could probably find a used one around $250 less than the 31mm lens. I really want this lens, but lacking in the fund department at the moment.

This recent thread on Pentax Forums about 24mm lenses might be helpful: