Strong in colour Agfa Color-Agolon 2.5/90 + its adapter

alex ph · Joined: 16 Mar 2013 Posts: 1571

Another high quaity projector lens, Agfa Color-Agolon 2.5/90. As compared to Leitz Colorplan, it has a larger diameter (barrel of 52mm), and it is justified by a larger glass and generally quite a massive lens. It was throttling in my reserve box, as I wished to adapt it in an elegant way. I finally found one... a sanitaryware two-sided variable size tube adapter which works just fine. Tomorrow I will take a shot of it and will it add it to the post.

Here are some samples from the lens taken wide open with Sony Nex. Estonished by its sharpness.

The lens likes red

#1 Unprocessed

#2 Autocontrast applied

#3 Autocontrast

It renders nicely and with a very good shrapness/saturation at various distances

#4 Close to mid range, autocontrast

#5 Further, autocontrast

#6 Closer, autocontrast

It gives a nice bokeh, including some jolly circles

#7

#8

#9

There is an older post by Pancolart very well presenting the lens in urban BW.

RnR · Expire: 2019-08-29

Wow!

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you RnR, glad you like it! I am pretty much impressed with the image quality the lens renders.

And here is the adapter

As you may see it is a PVC tube of constant diameter, with adjustable collars at both ends. The tube diameter is 58mm. The PVC is rather soft but thick, so no issue with useless flexibility of the tube. With help of collars it is squeezed up to 49-50mm.

I inserted Nex extension tubes at one side which lets grasping well the mount part. And a roll of paper at the other side, in order to let the lens slide smoother inside, as the rubber-like PVC is not ideal for precise focusing. The collar leaves a good margin to regulate the movement precisely.

One of the advantages of such a construction that it easily accepts various projector lenses with different flange distance, and of various barrel sizes. Another advantage is that it leaves a slight tilt effect, when you loosen the lower collar and move the PVC tube around the Nex extension ring. Even though the tilt capacity needs a screwdriver you bring with you. But the regulation is fast and not really annoying. Here is an example of such a slightly tilted image.

In case you are interested in such a solution for your projection lens, I found the adapter in sanitaryware of Leroy Merlin, a large chain of houseware and DIY stuff. It costed me 15 euros, which is a bit overcharged. I rate it better for half of the price. But it does well the job which it is not intended for.

Oldhand · Posted: Sun Jun 13, 2021 11:21 am Post subject:

Very beautiful results.
Congratulations on the ingenious adapter.
The lens is from a 6X6 slide projector I think.
It is certainly a good quality piece of glass
Tom

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you Tom! A very good lens indeed.

visualopsins · Expire: 2025-04-11

Maybe paint the inside of the PVC with flat black...

RnR · Expire: 2019-08-29

Always been fascinated with these slide projector lenses, but since a Contax Zeiss 85mm f2.8 hit my collection and realised my tinkering abilities are somewhere around zero, I'm happy living through more adventurous photographers Very Happy

alex ph · Joined: 16 Mar 2013 Posts: 1571

I may try to paint the inner surface of the paper roll, thank you for a good idea.

RnR, with such a PVC adapter you have no charge of a DIY skills, as long as all you need is a screwdriver to fasten the belts.

I tested the lens in more conventional urban context, always on Sony Nex, this time with some more contrast / saturation tweaks and I am very much pleased with the results.

#1

#2

#3

A simple conversion to BW works well too.

#4

#5

kds315* · Expire: 2021-03-09

Pancolart · Expire: 2013-11-18

Splendid samples. Lens comes in two different sizes. I guess one is for 6x6 and other for 35mm projector.

Zamo · Joined: 08 Feb 2019 Posts: 163

Very nice lens, the bokeh is very soft, really like it.

blotafton · Joined: 08 Aug 2013 Posts: 1554 Location: Sweden

Cool lens, didn't know about it. Does anyone know the optical design?

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you fellows! It's really nice to share with you the pleasure of discovering new lens qualities.

Oh yes Zamo, a "dirty old town" Smile

In fact, some well known cityscapes are conventional by their widespread recognizability.

I zoom sliding the lens up and down in the paper roll inserted in the PVC tube and sometimes turning it a bit for smoother and smaller steps. This double friction surface works pretty well. As long as you can adjust the collar tension and thus the surface adhesion, you can move the lens in a really precise way.

Blotafton, not me. I searched for some more technical details but did not find much.

I saw the lens was coming with a 35mm slide projector Agfacolor 250 AV which must be a high end equipment. There is still a couple of BIN offers in German ebay for around 50, the lens included. I once got an old and simplier Agfa projector from the 60s or even 50s equipped with Agomar 2.5/85 (presumably a triplet). It was for 35mm only slides, not dual-format, and the lens barrel was 52.5mm, exactly as this one or Kodak Carousel lenses. From that I concluded that Color-Agolon was also destined for 35mm slides. But I am far from being a firm expert in slide equipment.

dickb · Joined: 04 Apr 2008 Posts: 821

Projector lenses come in several diameters, 42.5mm, 52.5mm and 62.5mm being the most common. One way of using the 52.5mm size is with the cheap ebay extension tubes for Sony E mount, for instance. Those have a 57mm diameter thread, and a slightly narrower internal diameter. Using one or two layers of black velvety flocking material inside those tubes gives you a great non-reflective sliding tube. Alternatively there are 52.5mm to say 58mm adapters from RafCamera, that allow you to use the lens with a 58mm helicoid for even more convenient focussing. Alternatively you could go DIY and sand a 52 to 58mm stepdown ring to a fitting diameter and then use the M58 helicoid again.

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you, Dick, for the overview. I was leisurely searching for a cheap and pretty stable solution, so when I stumbled upon the sanitary adapter it fit my original intent. As you see, cheap Nex extension tube makes part of the adapter I made with it. Extension tube only with some velcro must work well too, I did not think about that before. Till now I avoided Raf Camera adapters for their price. As for filter rings, I tried first an M53 to M42 one: being too shallow, it does not fix the lens. Unless you stick it to the lens bottom. But that it irreversible.

sergtum · Joined: 14 Nov 2016 Posts: 735

alex ph · Joined: 16 Mar 2013 Posts: 1571

Thank you, sergtum!

alex ph · Joined: 16 Mar 2013 Posts: 1571

One more at close distance

Baekmann · Joined: 28 Feb 2021 Posts: 64

Wow, amazing shots! I need to make myself an adapter like that for my colorplan lens.

Doc Sharptail · Joined: 23 Nov 2020 Posts: 993 Location: Winnipeg Canada

Thanks for posting this.
I had been considering something similar for a project in mind.
The repair sleeve is good thinking.
I think brass tubing may still be available for a focusing liner too~ from the same source.
Things like this give us neophyte schmucks hope for a chance...

-D.S.

16:9 · Joined: 04 Apr 2014 Posts: 302 Location: UK

This lens is one of favourite PJ optics: more detail here and a better review pending. It's a five-element lens, by the way:
https://deltalenses.com/index.php/product/agfa-color-agolon-90-2-5/

simple.joy · Joined: 30 May 2022 Posts: 443

16:9 · Joined: 04 Apr 2014 Posts: 302 Location: UK

I know it goes without saying, but most PJ lenses have had a long, hot, hard life: it may be that your sample isn't the healthiest. Also obvious - but not often commented on - these are the least optimised of all alt.lenses for short range work. Or maybe you're just spoilt by that AV-Apogon!

One of the purposes of the growing Delta Hall of Fame is to rank projector lens sharpness. If you check the 'Far, Wide Open' metric here:
https://deltalenses.com/index.php/hall-of-fame-far-distance-wide-open/

You'll see there that at distance, the best PJ lenses are very sharp. For instance, the AV-Apogon 90 is sharper centre frame at f2.4 (scoring 8.eight) than the Schneider Apo-Componon 60/4 at f4 or the Tamron G2 70-200/2.8 at 100mm and f2.8 (both scoring 8.7).

I provide marks for centre-frame (Zone 1) and 'full-frame' corners (Zone 3) at near and far distances. At distance, the Zone 3 score for the AV-Apogon 90 at f2.4 dips to 8.0, whereas the Apo-Componon 60/4 at f4 scores 8.2 and the Tamron G2 70-200 at f2.8 scores 8.4.

Perhaps no surprise: a modern zoom lens is expected to perform well across the frame; an enlarger lens isn't expected to have sharp corners at long distance, and a projector lens isn't supposed to be taking pictures anyway.

My copy of the Agfa Color-Agolon 90 scored 7.6 / 6.5 - so, no, not in the upper echelons of PJ lens performance – comparable to the Leitz Colorplan. In fact, it's softer than the Reflecta Agomar 90 and the 'plastic fantastic' Agomar 85. (See the whole Hall of Fame for context). For mission-critical pixel-level sharpness, it's barely good enough, but it doesn't fall apart at sub-1m distances (there scoring 7.6 / 6.4), it's unusually well corrected, and it has lovely tonality and colour saturation.

So much can be done in post nowadays, that I set the bar for 'sharp enough' at “does it get me to DXO PhotoLab with enough information to make a crisp A3 print?” The Color-Agolon 90 just squeaks through as 'acceptable' for centrally-framed subjects. It also goes without saying that pixel-level sharpness doesn't matter for every image. It would be a poor kit-bag that only had a Color-Agolon 90 in it, but if you already have sharp, profiled modern zooms and primes, it offers a substantially different, attractive look: not wild 'look at me!!' bokeh – in fact, minimal mechanical vignetting is a real selling point for me – but funky, smooth and distinctive. I'm a fan.

If you want this look but sharper, try the Leica Super Colorplan: it's the only PJ lens I've seen that combines the aesthetic qualities of the Color-Agolon with the technicial proficiency of a modern lens.

Pancolart · Expire: 2013-11-18

alex ph · Joined: 16 Mar 2013 Posts: 1571