Guess: what lens it is made with?

Fabian · Joined: 04 Dec 2011 Posts: 254

I thought you were hinting at West Germany, but maybe I read wrong.

Cheap c-mount tv lens: China.

alex ph · Joined: 16 Mar 2013 Posts: 1571

Bingo, Fabian! It's Fujian CCTV 35mm 1.7. Did it look a bit like that from the beginning?

In about 20 hours I will post, as promised, two shots, wide open and stopped down.

alex ph · Joined: 16 Mar 2013 Posts: 1571

And all the players, sorry if I misled you with my hints. I did not mean to direct you to West Germany instead of East Germany. It could be a serious political mistake from my part! I meant it was not Germany at all.

It was a genuine pleasure.

Laurentiu Cristofor · Joined: 23 Oct 2010 Posts: 524 Location: WA, USA

Pancolart · Expire: 2013-11-18

Ha, ha i was only 5mm away with 30mm Pentacon. It has very similar bokeh and distinctive edge rendering.

std · Joined: 09 Feb 2010 Posts: 1827 Location: Bulgaria

ah Vault-Tech Very Happy

Another big Fallout fan like me ?

alex ph · Joined: 16 Mar 2013 Posts: 1571

Hello to all,

sorry for make you waiting. It took me more time than 20 hours to get to my shots.

Laurentiu Cristofor, it seems you have another version of Fujian. Yours gives an explicitly circular image, as you say: clear in the center and swirly blurred around. The mine does not lack that. But it is more unevenly distributed. As I said, the lens may give a blurry spot not far from the center, and then a clearer and better focused further away. Someone in the forums said it gives a partial effect of a tilt lens. Even if I have none, I saw some image samples, and I find it in a way similar.

Arkku, you asked me for two samples of one shot, wide open and stopped down to f5.6. Here they are. With an exception that the second one is stopped down rather to 8-11 (my lens have no clear mark, so I can only know an approximate aperture value):

This is a shot with the aperture wide open. Slightly sharpened after size reduction to 1600px, otherwise no post-procession.
You may look at the original out-of-camera image here.

This shot is with the lens stopped down to f8-f11. Also slightly sharpened after size reduction to 1600px, otherwise no post-procession.
Here is the out-of-camera original.

Do you notice that irregular sharpness all through the view field at the first picture and even slight effects of it in the second? Weird and interesting, isn't it?

alex ph

Laurentiu Cristofor · Joined: 23 Oct 2010 Posts: 524 Location: WA, USA

alex ph · Joined: 16 Mar 2013 Posts: 1571

Laurentiu Cristofor, I agree with you. The curved, circular effect is quite visible. What I mean is the fact that it seems more explicit in your and some other cases. And in my case it gives a slightly less visible swirl.

But what I wanted to underline even more is another strange effect of this lens. It is an irregular distribution of sharpness, as far as I may see. I mean an uneven distribution of sharpness at different distance from the center. To illustrate that, I made a photo of a plane object. And underlined several spots which have different sharpness:

Here you may see the original size and unprocessed image.

And here is the out-of-camera original jpeg.

What do you think about that?

The shot is always made with Sony Nex-5n, at ISO 800, 1/40 sec. Not a beauty, and could give probably a better result at ISO 100, 1/1000 sec. Still quite similar to what I usually have from that lens. The distance to the object plane was around 60-70cm.

fermy · Joined: 17 Feb 2012 Posts: 2877

Yes, Fujians have very strong field curvature. Here's what my Fujian 25 1.4 did from a perfectly straight wall (wide open test shot):

This looks horrible of course, but it's a fun little lens for little money, just treat it as super-Holga. Here's another wide open shot.

alex ph · Joined: 16 Mar 2013 Posts: 1571

Great tornado! Is it with NEX or 4/3?

fermy · Joined: 17 Feb 2012 Posts: 2877

This was with m4/3, I think 25mm vignettes on NEX.

Laurentiu Cristofor · Joined: 23 Oct 2010 Posts: 524 Location: WA, USA

alex ph · Joined: 16 Mar 2013 Posts: 1571

OK, later I will redo the test with a flat object with clear lines in a sunny day.

alex ph · Joined: 16 Mar 2013 Posts: 1571

Hi folks, I'm turning back to the topic in order to post another couple of shots. The idea I have is to show that Fujian gives not only a clear field curvature, but also a non-linear (non-circular) distribution of focus sharpness over the field. Previously, I made a shot of an old blanket to show that. But some persons justly noted that it was not perfectly plane to estimate the effect. More to that, the shot was made under a poor light condition.

It took me time to make another shot under a better natural light, of a plane surface with a regular, geometric design. As far as I can see, the effect I talk about remains on both shots, one made wide open, another with aperture at around F4-5.6.

Here are the shots:

1. @F1.7, out-of-camera jpg, resized, unprocessed. And here is the original where you may see it better.

2. @ F4-5.6 out-of-camera jpg, resized, unprocessed. And here is the full-sized original.

What I would like to outline is that in both cases you may observe some better focused spots further from the picture center than some worse focused spots. Just like in the shot of a blanket (a few posts upper in this thread) where I pointed out those spots with circles of different colors. Do you see the same thing, am I right?