Adox CMS20 – Fast Becoming a Favourite Slow Film

It’s always fun to try a new film – especially if it’s one of the more exotic ones.

This post is a mini test of 35mm Adox CMS20 black and white film, which claims to be ‘The sharpest, most fine-grained and highest resolving image recording system in the world‘ with an equivalent of 500Mp of detail on a 35mm negative. It’s original purpose was as an ultra high resolution and high contrast document film, but if developed properly it can yield a full range of mid-tones.

So, I had to give it a try.

Adox CMS20 Zuiko 50mm F1.4

Zuiko 50mm f1.4 at maximum aperture

Sample from the top left plus a few dust spots

As you’d expect it’s slow – 12 or 20 ISO, so your first problem might be finding a camera with a slow enough film speed setting. The Olympus OM2 goes down to 12 so that’s what’s been used here, along with my sharpest lens, a Zuiko 28mm f2 shooting at f5.6 or f8 – and a few from the Zuiko 50mm f1.4.

ADOX CMS20 Zuiko 50mm F1.4

Zuiko 50mm f1.4 stopped down to f5.6

Adox recommends a specific developer, ADOTECH II CMS which is quite pricey by comparison with ID11 or Rodinal, but as I wanted to do something approaching a proper test I used that. The processing is different to most films – the developer smells strongly of something like acetone, fixing takes a very short 45 seconds and is followed by a short wash time of 5 minutes. Caffenol, Rodinal and HC110 can all be used too.

ADOX CMS20 Zuiko 28mm f2

Zuiko 28mm f2 at f8. This is Knowlton Church, now a ruin, in the centre of a neolithic earth circle (a ’causewayed enclosure’) which is 4000 or so years old. A spooky location for a film test. There’s loads on Google if you’re interested.

As a general impression it looks a little like Ilford PAN F, and the slow speeds allow some nice shallow depth of field effects with a fast lens. It shares PAN F’s tendency towards high contrast darker images which I quite like.

ADOX CMS20 Zuiko 28mm f2

28mm f2 at f8 – White Mill Bridge.

The ultimate question though is – where’s the grain? Here are some enlargements from a scan from a Plustek 7500i set at 18 by 12.6 inches at 350 dpi which is close to it’s maximum physical resolution.

Here’s a shot of White Mill –  a National Trust property on the River Stour. No spotting or dust removal just straight from the scan.

ADOX CMS20 Zuiko 28mm f2 White Mill

28mm – White Mill

And here’s a couple of small samples from the shot  :-

The dovecotes in the centre of the picture. The brickwork is still sharp.

Enlargement from the top left of the shot

No grain at all, except a slight speckling in the sky which is just discernible. It’s easily out-resolving my best lens and scanner and showing no grain – something I can pick up with PAN F. These are only scans – Adox claim it can be printed grain free up to 2.5m horizontally from a 35mm negative and I’ve no reason to disbelieve them after this mini test.

The only downside of this film is that there’s no grain to hide small dust or spots, so for a large print it will take a lot of cloning/spotting.

If you haven’t already, give a few rolls a try – if nothing else shooting at 12 ISO is an experience! It’s available in 120 and as sheet film too – in 5×4 with a top lens, the resolution must be astonishing.


19 thoughts on “Adox CMS20 – Fast Becoming a Favourite Slow Film

  1. Thanks Steve – glad you found it useful!
    It’s extraordinary film, but 12/20 ISO means I’ll need to carry a tripod in the winter – something I’m less than enthusiastic about!

  2. I’m not familiar with Adox lines, but I heard some of their films were discontinued because some machinery broke down. I know some types of film are still being produced and even heard about a Silvermax which should have a high level of silver and have beautiful results. Thanks for the reminder, I need to do more research on this. Wonderful post today.

    • Some of the Adox films made in Croatia for Adox have been discontinued sadly – the CHS Art line and the Ortho films – which is a pity as I really was getting to like the CHS Art films. The film manufactured in Germany – including the new Silvermax – is still in production and it’s something I’m keen to try out.
      Thanks for the comment! It was fun doing the mini-test.

  3. Impressive range of mid-tones. I’ve found it really hard to control the contrast with CMS 20 using Adotech. I’ve been meaning to try Rodinal and stand development but maybe I just need to be more careful with my exposure and processing.

    • Hello Matt – I had the same problem with the first roll, but on the second I over diluted by 10% and cut the tank inversions to every 1 1/2 minutes which seemed to do the trick. Haven’t tried Rodinal yet but it sounds promising – and cheaper! Thanks for the comment.

  4. Amazing results but I’m not seeing much shadow detail on my Ipad. Is this a screen or scanner issue or is 12 ISO still on the “fast” side for CMS20?

    • Hello Ansel61
      It’s very tricky stuff and the default developing times are a bit too long (just my personal opinion). Over fixing can cause problems too! I overdiluted the bespoke developer by 10% then cut the dev time by 10% but it’s still very contrasty and the scanner needs the lowest contrast setting to get a reasonable image. The dev temperature at at ISO 12 is lower than ISO 20 which possibly helps to tame the contrast.
      I only got to the point of it being relatively useable after a bit of experimentation and a lot of exposure bracketing.
      Good luck with any further exposures!

  5. Forgot to say that I tried CMS20 a while back but shot it at ISO20 and didn’t like the tonality although you can’t argue with the sharpness or grain!

  6. Hi Robert,
    I finally couldn’t resist the curiosity your article stirred in me and bought a batch of CMS20 for christmas.
    Setting out on a long bike trip on a blazing clear winter day across the fields I chose an Olympus RC35 to test not only the film but also the the camera and myself.
    The lens (42mm/2.8) performes best at f8 resulting in a 30/s time while aiming for iso25 developement (as i wanted to be able to use the cameras automatic function while lowest ISO25)
    The results are very pleasing and although having read your article I was absolutely amazed to actually see my testtarget (a modern church tower 2miles away) with so much detail. On a 9x13cm print the tower appears at needle size thickness and can easily bee enlarged 10x.
    The very high contrast capabilities in mind I sat my son on a big stone, donned with a black wollen hat and dark blue jacket sun blazing right into his winter-pale face. Choosing a grade5 paper for the fun of it the face seemingly pops right out of the picture.
    What a great find!
    Thank you.

    • Hello Nick – very pleased you like it and glad to know the article inspired some curiosity! It is a superb film – I’ll try some more of it when spring comes around, at the moment I’m playing with the other end of the ISO scale – Ilford Delta 3200 – which is something of a contrast in the grain department!

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