Over the past couple of years, I’ve made a bit of a hobby out of collecting and using old lenses on my Fujifilm X mirrorless cameras. (I’ve discussed some of them in a previous blog post.) More specifically, I’ve been using M42 lenses. M42 is a lens mounting standard that was used by many camera manufacturers from 1949 to the 1980’s. There is a wide range of lenses available for this mount and they can be purchased quite cheaply now. Of course there are more expensive versions from brands like Zeiss, but there are plenty of good, cheap lenses from brands like Helios, Vivitar and my personal favorite, Asahi Pentax.
Other lens mounts like Canon, Nikon, and even Leica can be adapted your mirrorless camera, but they are usually much more expensive than M42. I’ll focus on M42 in this blog post.
Reasons to Use M42
- Many M42 lenses are relatively cheap! They are typically a fraction of the price of equivalent modern lenses. This allows you to play with various lenses and focal lengths without breaking the bank.
- The M42 standard easily adapted to many camera mounts. I talk about Fujifilm cameras in this blog post, but you can buy M42 mount adapters for most if not all major camera manufacturers. That means these lenses can be useful even if you switch camera systems. I’ve personally got M42 adapters for my Canon full frame bodies, but I think these lenses really shine on mirrorless cameras, especially with focus peaking.
- Great build and mechanical quality. All the lenses I’ve had experience with are built like a tank! No wonder they’ve lasted this long.
- Overall, it’s just lots of fun to use these lenses. They are sharp, well-built, and have their own character.
Reasons Not to Use M42
- Manual focus only. M42 lenses have no AF. However, the lack of autofocus is not such a big deal on mirrorless cameras like the Fuji X series, as they have focus peaking and other focusing aids built in.
- Old lens design and tech. Vintage lenses are not as clinically sharp as modern lenses. Also, aberrations and flare are not handled quite as well due to older lens coating technology. However, this can also be a benefit if you want a classic/vintage look.
- Adapters make the lens more bulky. Especially with smaller mirrorless cameras, adapters must be a certain size to in order to compensate for the distance between the lens and the sensor. Unfortunately, this adds a bit of bulk to the combo. SLR adapters are smaller since the distance is more similar to the original M42 camera design.

Lens without adapter vs. Lens with adapter. Noticeable size difference.

M42 adapter and Helios 58mm on my Canon 6D. Note the much smaller size of the adapter.
Mount Adapters
Like lenses, the available adapters vary in quality and price. I recommend skipping the generic adapters and going for one like the KF concept. The cheapest generic adapters do the job, but the build quality is a bit lower and might need a bit of adjustment to line up the top of the lens. There are also specialized adapters that enhance functionality, such as tilt and tilt-shift adapters from Kipon, which I would love to try in the future. There is also the Lens Turbo II from Zhongyi, which removes the crop factor and makes the lens effectively faster via an additional lens element. For this blog post, I will focus on the regular adapters that simply connect the M42 lens to the camera, therefore keeping the 1.5 crop factor.

Left: Generic M42-Fuji X adapter with hex key wrench to adjust lens rotation. Right: K&F Concept M42-Fuji X adapter with better build quality (and looks).
Lenses
Asahi Pentax SMC Takumar 28mm f/3.5
Pros: small, sharp, good contrast, great build quality, 40-ish mm equivalent close to “perfect normal”, short infinity focus with nice focusing ring feel
Cons: flare prone (as many M42 lenses are), not a low light lens, (but should be okay given the high ISO performance of Fuji bodies), some chromatic aberrations, it is mostly an outdoor daytime lens
Typical price: $45 USD and up
Sample images:





Helios 44-2 58mm f/2.0
Pros: famous swirly bokeh, built like a Russian tank, fairly fast at f/2.0, stepless aperture ring (some Helios variants may not have this), great 85-ish portrait focal length on crop sensor
Cons: lots of flare and aberrations (flare can be a good thing), a bit soft at 2.0
Typical price: $30 USD and up
Sample images:





Asahi Pentax (SMC) Takumar 135mm f/3.5
Pros: small, built well, 200mm equivalent, especially love the metal hood, nice long focus throw for precise focusing, looks awesome (like a little cannon ;)), nice long reach in a small package
Cons: soft wide open, not particularly fast lens, but will do well outdoors
Typical price: $30 USD and up
Sample images:




Asahi Pentax SMC/ Tele-Takumar 400mm f/5.6

Asahi Pentax SMC Takumar 400mm f/5.6 as purchased from eBay. Price: $159 USD shipped.
Pros: long reach (600mm equivalent on Fuji!), built in metal lens hood is great, sharp especially when stopped down a bit
Cons: 8 meters (26.2 ft) minimum focus distance (sounds really far, but it’s really quite fine for outdoor landscape and travel use), relatively slow 5.6 minimum aperture, again this is mainly an outdoor lens, can be a bit challenging to nail focus, not that easy to find for sale
You will need a tripod to keep this lens stable for the most part.
Typical price: $140 USD and up
Sample images:



Overall, all of these lenses produce great images, have excellent build quality, and have relatively low price.
Tips For Choosing Your Lenses
- Decide what focal length you need and want
- Check lens reviews and sample images online. Pentax Forums is a great resource for Takumar lenses.
- Be on the lookout for good deals on eBay or Amazon.
- Check the seller’s description and images thoroughly and make sure the lens is in good condition. The good sellers will typically provide all the information you need to make a good selection.
- Things to avoid are fungus, too many scratches on the lens elements, and poor condition of the lens barrel/mechanics.
- Look for included accessories. I personally like the ones that have caps, hoods, and cases, and I’m willing to pay a little bit more for those.

Ready for action! Total cost for 4 lenses and 4 adapters: about $360 USD shipped.
Final Thoughts
I hope you enjoyed this little peek into the world of M42. Again, this information doesn’t just apply for Fujifilm cameras, but all major camera manufacturers that have M42 adapters available. The rabbit hole goes deep with vintage lenses, and I barely scratched the surface here. I definitely recommend trying out vintage lenses for your mirrorless camera. If you’re worried about autofocus, I can tell you that it does get easier as you practice. These days, I’ve been nailing focus pretty easily with the vintage lenses. All in all it’s really fun and useful, especially if you’ve been dying to try a certain focal length, but aren’t ready to pull the trigger on an equivalent current model lens.
UPDATE: I’ve also tested some Olympus OM Lenses on my Fuji system. Check it out!
Video
I put together a video where I talk about these lenses then go out and shoot with them. Please check it out!