Tips and Tricks
Posted by Bengt Köhler Sandberg 2013-07-31
I have got quite a lot of questions about my homemade lenses and its about time I write something about them.
There are not made from scratch and I have taken lenses elements and things I have found in other products and then glued them in a lenshousing.
And I have made a few of these throughout the years.
But found a broken Nikon 100mm Series E lens which I took out all the lens elements from and glued in binocular lens.
This lens is supprisingly sharp in the middle and gets very blurry at the corners but that what you get when you only use one lens element.
My widest single element lens and it's about 35mm.
Plastic element that are very soft and only got some detail in the very middle.
This also had a plastic tubing for camera housing at first but remade it with a housing from a pentacon 50mm.
It was not that easy to remove the lens element out of this so I ended up using a hammer and screwdriver to do the job.
Carl Zeiss Jena DDR Flektogon 35mm f/2.4 (m42).
And it was a nice working lens before I got it.
But it's like breaking a rock someone might think.
Yes but you can break a rock if you really want to, might take some violence but it can be done and let's just leave it to that.
But instead of just throwing it in the bin I thought I try to experiment to rearrange the lenses and see what it might do.
So I ended up completely removing the front element and flipping another so it faces the wrong way.
This made the lens to do everything the manufacturer try to avoid at all cost.
The lower and focusing part is from another lens which I don't remember the name of, the second half is of the Zeiss lens which is glued together.
Ended up to be a good looking lens if I say so myself.
At least if you compare it to my other homemade toy lenses and you don't look to close.
Have now also a modern 4x5" large format camera.
A camera type which can be perfect for homebuilt stuff.
And here are my first home built lens for this.
This is done in the same way as my first two.
It have one lens element and I have taken this lens from the same binocular as my first home build.
But this have the big front lens element of the binocular.
Used the whole front plastic part of the binocular and the have almost the same diameter as a old shutter I have.
So the build was very simple and I only needed to file down the plastic so it could be screwed into the shutter.
It has no aperture so it's fixed at around f/5.6 and the focal length is about 180mm.
Image quality is also very similar to my first home built.
It has quite good center sharpness and gets very fast blurry towards the sides.
This do also vinjett a lot but it's not the lens element it self that do this.
And it is the shutter which is smaller than the lens and also mounted at some distance from lens.
I find this to work quite well and the picture get both blurry and darker towards the sides.
One great thing about using a lens like this on a large format camera which have lens movement.
Meaning that you can move the entire lens up or down or side to side.
This moves where the center of the lens are on the negative and you can much easier get good sharpness where you want it.
Here are some examples and their directly from the scanner.
I'm very happy with its image quality and love the bokeh and blur.
Here is one image of the first test pic and found the vinjetting a bit too heavy.
Filed it a little more so the lens element came closer to the shutter whith gave less.
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