Photoclubalpha

After acquiring an M42 to A mount adapter, tried the Vivitar 50/1.7 screw mount lens on A700

Just a shot wide open.



And a 100% crop

I suspect the iris diaphragm is not circular on this one! It seems a pretty good lens. It was made by Cosina for the Vivitar branded cameras, which were Cosinas.

If I come to Armenia, I'm getting a pointy hat. I already have a pointy head and it will fit perfectly

David

Unfortunately that lens is not mine (yet), so for the time being I can't post more shots... Oh wait I made another shot-test with it and I hope that will satisfy your needs (both Don and David). I'll be back in a few moments.

So here it goes:




And a 100% crop



I have no other shots with that lens, but I will post on a separate thread shots with Soviet made Jupiter-37A 135mm f/3.5 lens (M42). Also a small lens, a very tiny little one called Industar-50-2 which is a screw mount lens of 50mm f/3.5. Other details and info will follow in a new thread (I'm testing it on a bellows ) so have patience.

Oh, I forgot, David, you're right, I did pay attention to the diaphragm which was not circular, as you pointed it out. One thing that kept me from buying it from the guy in the first picture was the stiffness of the focus at the far end.

So, do you recommend this lens? Don't ask the price. Have no idea.

Sonolta wrote:

Sonolta wrote:...but the bokeh (at least on that shot) looks to be a bit on the ovular and hard edged side.
-Sonolta

Doc...that's what I said. You seemed to have forgotten our bokeh discussion from the other day. The oval bokeh wide open is a dead giveaway of the non-circular diaphram.

Remember? I posted the heart shaped bokeh and several other aperture shape info links on that 20mm thread.

http://www.diyphotography.net/diy_create_your_own_bokeh" onclick="window.open(this.href);return false;

http://ca.konicaminolta.com/products/co ... f_cir.html" onclick="window.open(this.href);return false;

-Sonolta

Back in the 1970s, Komura made a 100mm f2.5 lens which could be taken apart easily. They didn't intend it for this use, but I was able to put star shaped and slit diaphragms inside it. A few years later, Cokin introduced a slit aperture kit which relied on using a 50mm f1.4 and putting special shaped apertures in front of the lens, like a filter. It does not work as well as an aperture placed within the lens, but you can use stars, hearts, slits or cut shapes of your own. In 1981, Izumar marketed an item called the Pan-Focus Lens. This was a 50mm f-something (I think around f4) lens in a T-mount, which could only be focused by unscrewing the lens in the mount. It came with an f64 aperture, for semi-pinhole effects, or you could use it wide open for a soft focus effect. It was also possible to make apertures and insert them. I had a Panfocus lens and now I can't find it. I am sure I never sold it or threw it away by mistake.

The modern equivalent is the LensBaby range, very similar to the Izumar in concept but much faster apertures (f2.8 or f2) and a set of apertures. Heart and star apertures are included with the LensBaby G3 and the new model which replaces it.

I did an article on the LensBaby in the first month of Photoclubalpha: http://www.photoclubalpha.com/2007/06/1 ... wing-lens/

I have just updated it with the news of their latest models, and added two pictures I took in August 2007 using the Creative Aperture kit they sent me just after the original report was posted. These appeared in f2 magazine but I forgot to update the post here.

David

Dr. Harout wrote:So, do you recommend this lens? Don't ask the price. Have no idea.

For experiments, yes. $15 I would say, maximum.

David