Sekor 180mm f4.5 for Mamiya C3

Neare · Joined: 09 Sep 2009 Posts: 43 Location: New Zealand

Here's a lens most of you will not really think about using, however it is quite an interesting one so I thought I'd show you.

It's the Telephoto lens for the Mamiya C series TLR's.

What's interesting about it however is its strong distortion.

I'm sorry that these are not the best TEST scenario shots, so bare with me. Its purpose is just to show.

All shots are of course, unedited. Shot with Fuji Velvia 100

Shot at f8

Notice the huge amount of distortion even even when the lens is stopped down quite a bit.

Shot of f11

Still very noticeable distortion, though handles flare quite well.

Shot Wide Open at f4.5

The Distortion areas can render some interesting Bokeh when shot Wide Open however.

Shot Wide Open at f4.5

Mounted on the beast itself.

For general photography purposes Id say that this lens is quite useless. Though If you use it wisely it can create some great effects I'm sure. I imagine the distortion will carry all the way through to f45, which is quite a feat. The original Lensbaby perhaps?

Sharpness wise, ok. Not great. And gives fairly less contrasty tones to my eyes which can be good or bad in some cases.

Again I know these aren't standard test shots, but I'm sure you can get an idea of how this thing works.

Ari

Abbazz · Joined: 23 Jun 2007 Posts: 1098 Location: Jakarta

Ari,

I am very surpised by your results with the 180mm lens. I have one of those and I use it from time to time on my Mamiya C330s. It delivers good results, especially when stopped down a bit, even though it's probably not the sharpest lens in the world. I don't have any pictures available but I have found these online:

Photo credit: Dave Moss

Photo credit: Kalin Ruichev

Photo credit: Ian Tindale

My guess is that your lens is missing an element, probably the rearmost one. If you check the lens visually, there should be a glass element visible at the back of the lens, almost flush with the rear flange:

Illustration credit: Dr. Robert Smith

Cheers!

Abbazz

Xpres · Expire: 2014-10-28

If not the missing rear element, then maybe you're using the viewing lens rather than the taking lens?
I have the viewing lens of an old Yashica twin lens set up for effects just as you show here.
Not sure why this should be the case - apart from the viewing lens needing to be very bright. Anyone?

Abbazz · Joined: 23 Jun 2007 Posts: 1098 Location: Jakarta

Neare · Joined: 09 Sep 2009 Posts: 43 Location: New Zealand

Very interesting.

The viewing lens also has the distortion, I'm pretty sure as I've been using it for some time that I'm not mounting it backwards. =D Otherwise there would be no shutter. All elements accounted for as well.

Note that the last photo shows the lens has the silver ring instead of the black one. This is because this lens is one of the earlier models of the 180mm, much less common. Perhaps this is the reason.

JWH · Joined: 26 Aug 2009 Posts: 120 Location: Netherlands

I just love that first photo for some reason, mind me asking what the green ball is doing in the middle of it?

Neare · Joined: 09 Sep 2009 Posts: 43 Location: New Zealand

scsambrook · Expire: 2011-11-18

Something is surely not right with this 180 Sekor. I had a C3 once, and although the lenses weren't Hasselblad quality they were still good. The 180 didn't have this sort of distortion - although I think it makes for some really interesting images Smile

Even odder is that you get the same effect in the viewfinder. My guess is that it's been stripped at some time for cleaning and whoever did it re-assembled both sets in an identical, but somehow incorrect, manner.

I got exactly that sort of result once when I dismantled my 5-element projector lens and managed to "flip" one of them when putting it back together. Took me a while to figure out where I'd gone wrong!

Neare · Joined: 09 Sep 2009 Posts: 43 Location: New Zealand

Haha so my lens is 1 in a million, nice.

I acquired my Mamiya C3 off a man who was one of the original developers of Ilford Delta. This was his studio camera for years and this is one of the lenses he happily used for professional work. Weird.

Well anyway, I'll see if I can use it to create some interesting effects in the future.

rawhead · Expire: 2014-04-29

My bet is also on flipped innter element. I got something similar when I CLA'd my Yashica-Mat, and flipped the second element during reassembly.

Took me a while to figure that one out, too Very Happy

When fixed: