Lockdown relaxed with Zoom Decar 85-150mm

alex ph · Joined: 16 Mar 2013 Posts: 1674

I've provided myself with a pretty special zoom from the 1960s, I think, which is destined for slide projection. It is called Zoom Decar 85-150mm. That's all what is indicated on it, with no info on maker and of its constant aperture. The construction is pretty simple and ingenuous. It has four lenses, with rear and front easily detachable, as in many projector lenses of the era. And the zoom mecanism which combines the idea of a simple slot guided mouvement and a simple threaded ring. What is amazing, it works fine and looks more relyable than more sophisticated constructions.

All glass is uncoated and the edges are not blackened. So, it's a situation pretty uncommon for a zoom lens, with simply "natural" glass. I doubt you find it in any dedicated camera zoom. The resulting image has much of CA and low contrast. Besides, image edges are very fuzzy, and that is visible even when projecting slides. In fact, that's a "bad" projection lens and technically poor zoom.

BUT pushed far enough a BW conversion of the shots looks pretty awsome, both for its dramatic impression (and natural vignetting) and tonality. It is certainly not the easiest and surest lens to operate. Many times I needed to fix a distance and then to play with zoom shift to get an image focused. And sometimes I lost it completely, even though in the live view it looked OK. But those shots that came out well have some interesting character.

All shots are taken with Sony A7 and processed quite heavily as for contrast and exposure compensation.

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hasenbein · Joined: 15 May 2020 Posts: 93

You are just imagining something here.

These are just bad photos taken with a bad lens. That's all there is to it. Sorry.

Oldhand · Posted: Mon Jun 01, 2020 8:07 am Post subject:

Some old slide projectors came with a zoom lens for adjusting the size of the projected image. The Kodak Carosel was one of these.
There was only wide aperture.
Your images are probably typical of a similar lens, but maybe not quite as good.
Still, there is a nice dreamy quality about some of them
Like 1 small

D1N0 · Joined: 07 Aug 2012 Posts: 2537

Seems like a good lens for shooting dream sequences in video

alex ph · Joined: 16 Mar 2013 Posts: 1674

Thank you for your feedback, Tom and D1N0! That's what I thought about playing with BW. The lens rendering reminds quite a bit vacation shots from the 1950s taken with "crappy" Brownies and and cheap triplets, or with 8mm video cameras, with much of details lost, harsh contrast and glow. And these dramatic simplifications and shiny sun surfaces of the shot bodies created a clear allusion of memories or dream.

from here

from Zoom Decar 85-150

Hasenbein, it seems you don't accept the point of a "character" lens and directly associate shot quality with the lens' perfection?

hasenbein · Joined: 15 May 2020 Posts: 93

If the "character" is entirely by chance (because it's simply a poor lens) then I don't give a sh** about that "character", especially if it means just horrible unsharpness.

You actually get better pictures with a pinhole camera, and that says something.

alex ph · Joined: 16 Mar 2013 Posts: 1674

Hasenbein, I hope you have nothing against pinhole cameras. You don't really need of salty rhetoric to express your taste preferences in this forum.

Oldhand · Posted: Tue Jun 02, 2020 5:58 am Post subject:

tb_a · Expire: 2019-08-28

It doesn't make much sense to discuss different tastes. I don't like lenses with "character" as well and will never understand why some folks like crappy lenses.
However, everybody should do whatever he likes. No problem with that.
Finally I appreciate contributions like this one as I can learn which lenses to avoid.

alex ph · Joined: 16 Mar 2013 Posts: 1674

For reference, this is how the lens looks like (a shot taken from the net)

Looking at the "starwars" exterior, I was already pretty intrigued with an eventual "specialty" of its rendering.

And here is the simple focusing mechanism, with the threaded head unscrewed

alex ph · Joined: 16 Mar 2013 Posts: 1674

I found an amusement in recolourizing some of the shots converted into BW, with an online service colourise.sg. I wished to see if the retro effect keeps up. It does indeed, and the computative intelligence is pretty impressive, to recognize human figures even in bent and uncomplete shapes.

#1 Here is the shot #6 from the first set above

#2 And here is the "original" jpg (in fact, already downsized and colour / contrast corrected). Funny how the algorythm swapped blue and black in some clothes, as compared to the original

#3 And here is #4 from the first set above, recolourized.

#4 The jpeg before its BW conversion. Some colours, like bright yellow and acid green are not recognized, the blue is swapped again. And still very impressive

To my taste, the recolourized images, with a muted palette, look more interesting.

visualopsins · Expire: 2025-04-11

Reds get mangled too. Smile

Find an old Coca Cola bottle, use a file to score around lower part, tap sharply on score to break off bottom. Now there's a lens with REAL character. Somebody will like it. Not me, but no problem. I've also heard but never tried thickly coating a good lens with Vaseline to give some character.

alex ph · Joined: 16 Mar 2013 Posts: 1674

Yes, robots and scripts are still full of imperfections...

Thst's funny, I even bought a small tube of vaseline, to try the "glow effect". I didn't dare to put it on a UV filter yet, having no idea of the right amount. I'll try that later anyway. But should I post the result? Laugh 1