The Light Slide

fun with photography

Auto Alpa 50mm 1.7 Macro: First shots

Sure, sex is great, but have you ever managed to track down a rare and mysterious lens in a dirty auction lot of somebody's grandpa's camera collection and win it for a tiny fraction of the going (used) price, plus a nice clacky-feeling film camera and several other lenses for a little lagniappe?

I hope so, because it's a great feeling!

It is my pleasure to introduce you to the Auto Alpa 50mm 1.7 Macro.

It's an m42 lens with a minimum aperture of f/16 and a minimum focus distance of 0.27m.

First things first: SAMPLES!

Nota bene: My copy is a bit dusty, and oily around the outside edge of the front element from the aperture grease… it needs a CLA.  That's the downside of the dirty camera lot fun.

Here's how it performs on my Pentax K10D:

Palo verde: not my favorite
stopped down to f/11 or so due to wind

It gives flowers and plants an almost meaty, gel-like look… which is intriguingly different than the usual suspects.

It fell
close to wide open

Of course, this is edited with my own Portra-like color grading and a selective radial highlight/shadow… but isn't it dreamy? And yet it still has some 3D pop. How do you combine dreamy and 3D pop in one lens?

New prickly pear pad
stopped down quite a bit

The bokeh can be… paint-brush-stroke-like. It's unfair to judge bokeh with a rocky, spikey desert background; most lenses seem to come out harsh, most internet comparisons use photos taken in places with plush foliage. And of course it's not a very long lens.

I'm excited to try this lens up on the mountain where soft, leafy things live.

Prickly pear blossoms, closed
isn't the bokeh interesting?
Closing prickly pear blossom
slightly stopped down

Is it actually… swirling??

Stopped down, it's actually quite sharp:

Cholla cactus skeleton
pretty stopped down… should I take notes on these things? seems like a lot of work

It does well in black and white and has really nice micro contrast, especially considering the inside of the front element is oily:

B&W contrast example

It passes the cat test, too — not too harsh! Very pleasing color and her eyes look beautiful:

The all-important cat test
say hi to Zaha with the pleasing bokeh (yes I gave her eyes a little extra sat)

It does well in real tests of sharpness (text!):

Sharpness test: distance
Sharpness test: closer

Click on the peach flower below for the max size, and just look at those absolutely tiny little balls of pollen on the edge of the flower petals!

Prickly pear bloom, fading

The level of detail and that gel-like render makes me want to stick it on my Sigma SD1 Merrill. My m42 adapter is in the mail… I wonder how it'll look!

OOC & Processing

All of the foregoing examples were post-processed, of course, but color is good with this lens right out of the box, no doubt due in large part to the excellent Pentax K10D. I haven't tried this lens on my Sigma yet, which tends to have less flattering color out of the box (but tons of editing latitude).

Here's an example of a straight-out-of-camera raw file and how I edited it:

SOOC Cactus
Hedgehog cactus
my vaguely portra-esque edit

The way the lens renders sooc is ideal for the way I like to edit this kind of photograph. The desert is harder to edit to begin with, I think, with its limited color palette, there are fewer places you can go to with your pp… this lens is friendly to it, somehow.

I tried this same action/approach on close-up photos of the similar subjects from another lens and even with adjustments for sensor/color/scene, it didn't work half as well.

Future adventures

Next up, I'd like to try:

  • distant and infinity performance (my official Pentax-brand M42 adapter hadn't arrived)
  • performance on a higher-res camera
  • performance on the SD1 Merrill foveon sensor
  • performance on full-frame
  • extension tubes and on a tripod
  • more b&w
  • different, maybe softer, subjects
  • infrared! (but I can't, yet; don't have a body to adapt it to)


I love it. Love, love, love.

I really, really love the way this Alpa lens renders plants, petals, rocks, and cats… basically all the things I photograph most. It's different in a way that's hard to put a finger on. Small things have real presence with this lens, insubstantial things like flower petals have great weight.

The bokeh isn't too noisy or jarring even when the background is full of slender, stabby things.  But it's also not your bog standard smooth and flavorless "bokeh monster." It's unusual!

It's tons of fun to shoot, fun to post-process, and it'll be a joy to test it out some more.

This is a lens I see myself using often.

I could see it being worth $200-300. I paid at the low end of that including two other m42 lenses and a working 35mm film camera.

Unless you've got money to burn, I can't recommend spending $400-800 to buy a copy off eBay. But watch for Alpa bundles and maybe you'll find one like I did.

Sidebar: Can I just give some love to the Pentax K10D? It's just a frigging delight. Thanks so much to James from Snappiness for teaching me about it & inspiring my purchase.

Next time I'll post what I know about the origins of this mysterious and highly disputed lens…