Helios rear elements as (fun)lenses - The element of suprise

[ForenSeil]

When I was playing around with lens parts I recognized that the rear elements of Helios/Biotars are able to project.

Here's a rear element (I hope I remember correctly) of a Helios 44M 58mm 1:2





I clamped it to a leftover of an Industar 61 (Leica M39 mount) whose helicoid was used for focusing. I didn't measure the focal distance but I guess it's possible to reach infinty on M42 etc. if you find a way to adapt it which allows focusing
Not very beautyful but it works very well.


First tests:

Very soft focus


@Infinity


Raindrops on the window








(defocused, it's not easy to focus with such a soft lens )


(also defocused, over infinty, but not by accident)

Any experience with that? I would love to see this lens used on some flowers with raindrops (and a hood) but the weather my day's shedule are not friends of this projekt

PS: Contrast could be much better. My copy is hazed a little.

[iangreenhalgh1]

What you have there is the rear 3 elements.

I took the rear group out of a Helios-44 and use the lens with just the front group, which made it a triplet with an effective focal length of 116mm. You should try that, works really well.

[ForenSeil]

[gmonkman1]

nice.....you could call this " the element of surprise ."....lol

[ForenSeil]

[martinsmith99]

[Lightshow]

It should give interesting results for portraits.

[ForenSeil]

[DSG]

[leilacandy]

Wow!

[ForenSeil]

I've just tried the Helios 40/Cyclop 85mm F1.5 rear element... similar effect, sharper and more contrasty in center but with a longer focal length

[vilva]

This rear element (or actually group) can be used as a pretty good soft-focus lens with a hard to beat bokeh, and mounting it backwards provides a very compact design but without an aperture mechanism. I glued the original rear end of the group onto an M42 macro reversal ring so the group could be mounted totally inside an M42 17-32 mm focusing helicoid. I had previously removed the thread section from the other end of the reversal ring so the lens assembly adds only less than 3 mm to the thickness of the helicoid, which means the total thickness is less than 20 mm, i.e., roughly that of a CZ 45/2.8 Tessar*. The focusing range is from about 40 cm to almost infinity, which is quite OK as I see no need for infinity focus when using a soft-focus lens.

Here is a slightly cropped test shot:



and an intentionally out of focus shot through a glass door showing the bokeh behavior when there are no very bright highlights:



Veijo

[martinsmith99]

That's a nice result.