The Best £15 You Can Spend On Your DSLR

My first DSLR was a used 2009 Pentax K-x, in 2014.

At this point I’d already been shooting film SLRs a couple of years and had fallen for a number of vintage manual aperture, manual focus lenses, like the peerless Takumars, and the Helios 44 series.

In researching DSLRs, I was delighted to discover that Pentax had retained their K mount since its introduction in 1975, so any K mount lens could be used on a modern Pentax DSLR.


Lenses like the excellent Pentax-M 50/1.7 and the humble yet frequently impressive Ricoh Rikenon 50/2.

I also found out that with a simple adapter ring, I could use the older M42 screw mount lenses I mentioned before on my DSLR. 

However it wasn’t unbridled happines from the outset.

The cheap adapter I went for gave me issues with infinity focus (it protruded from the camera body, so the lenses wouldn’t mount flush against it), and I was baffled at first by why my lenses on the DSLR seemed to be “zoomed in” much closer than when I used them on my film SLRs.


Further learning revealed that because the APS-C sensor in the DSLR was smaller than a frame of film, there was a crop factor of 1.5x.

Meaning that a 50mm lens on a 35mm film camera gives you an equivalent 75mm field of view (ie 50mm x 1.5) on a DSLR.

In time, I shot more with a DSLR than an SLR, so the focal lengths and fields of view just became normal to me, and it was no longer an issue.


On the adapter front, I later bought an official Pentax version, which still only cost about £15, and fits inside the camera mount, so lenses fit flush against the body, as they should.

And, arguably, this is the best £15 I have spent on my Pentax system, because it lets me use all those classic M42 lenses I own (and have owned – and thousands I (yet) haven’t).

Many of the Pentax K and M series lenses are almost as lovely as their Takumar predecessors, as well as being optically excellent.

But being able to use the beautiful Taks, plus other lenses that there is no direct equivalent of in Pentax K mount – like the Carl Zeiss trio of the Flektogon 35.2.5, Pancolar 50/1.8 and Sonnar 135/3.5, the Helios 44-2 85/2 with its unique bokeh, and the Jupiter-37A 135/3.5 I recently fawned over here – make the adapter an essential purchase in my eyes for any Pentax DSLR owner.


Indeed, a number of other digital camera systems have M42 adapters available too. 

I’ve shot M42 lenses on Sony A mount DSLRs, a Sony NEX 3N and a Panasonic Lumix GF1. It’s an excellent investment that opens a world of opportunity.

The photographs in this post were all made with a Pentax DLSR and M42 lens.

How about you? Have you used M42 lenses on a Pentax DSLR – or any other digital camera? 

Please let us know in the comments below (and don’t forget to tick the “Notify me of new comments via email” box to follow the conversation).

Thanks for looking.

What Next?

Share this post with someone you think will enjoy it using the buttons below.

Read a random post from the archives.

See what I’m up to About Now.

11 thoughts on “The Best £15 You Can Spend On Your DSLR”

  1. I have an M42 to K converter and I’ve used it a little on my K10D. But it has been more a novelty for me than a way to do serious work. I bought an AF zoom for my K10D and that’s what I use on it 99% of the time now.

    1. Jim I’m quite surprised to hear you say it’s been a novelty and not a more serious option. I thought you had a few Takumars, maybe I’m mistaken. Many people love the old CCD sensor DSLRs (like the K10D) with Takumars.

      1. I just find the camera more cumbersome to use than it’s worth when I shoot my old lenses. I get perfectly acceptable results from autofocus K mount lenses with less hassle.

  2. I must be the odd one here. I’ve had my Fuji X-T2 for two years. I’ve had my Pentax Spotmatic II for nine months. I have four M42 Mount prime lenses but only one X-Mount (zoom) lens. With an adapter for my Fuji X-T2, it’s easy to use the camera’s focus peaking system with these manual focus lenses. I guess it was the most practical solution for my budget.

    1. This is very similar to how I was with my Sony NEX. I never had a native lens for it, I only bought it to try out old manual lenses, and had them in half a dozen different mounts, including of course M42.

  3. Beautiful shots Dan, amazing color.

    I’ve used my SMC Takumar 50mm f1.4 on both my K-5 and my Olympus E-M10 Mk II and the results always make me very happy. The Olympus, with its 2x crop factor make the Tak a wonderful 100mm equivalent portrait lens.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s