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Modifying Helios 44-2 for extra bokeh?
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PostPosted: Fri Apr 01, 2011 9:20 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
Well, I'm lucky, I have a Prinzgalazy M42 tube that is 18mm. I shall give it a try tomorrow.

I might have to grind it down by a mm or so to get the register spot on but it should work eventualy with some trial and error.


You will not focus to infinity but I think the 18 mm tube still will allow you to focus in a range that is of practical use.
Another idea would be to get a shorter tube (I think 14 mm was an usual lenght) and shim it on the camera side.

Quote:

How should I test it? I'm guessing point it at something more than 50m away, set the focus to infinity and take a shot and see if it's in focus?


You don't use it on a SLR? If yes than what you see in the mirrorbox will come to the film too.
If you have a splitscreen on the groundglass, than point to the moon. Should be far away enough to be considered infinity.

Quote:

One other thing occurred to me. What would be the effect of mounting the rear group I removed in the extension tube so that all I have done is move the two groups further apart?


On the very same site where the schematics you posted came from is another modification that does exactly the thing you mention.

Quote:

Oh, one final thing, I have an M42-EOS adapter I am mounting this with, do I need to factor in the thickness of that adapter when calculating the tube length? If the adapter is 1mm thick doesn that mean the tube should actually be 16.2mm rather than 17.2mm?


I think so.
Did the lens (or any other M42 lens) without the macro tube (I mean before the modification) focused to infinity with the adapter? Than you don't need to factor it in.


PostPosted: Fri Apr 01, 2011 9:54 pm    Post subject: Reply with quote
Eugen Mezei wrote:
You will not focus to infinity but I think the 18 mm tube still will allow you to focus in a range that is of practical use.
Another idea would be to get a shorter tube (I think 14 mm was an usual lenght) and shim it on the camera side.


Yes, I thought the same too - that the 18mm tube will at least allow me to go try the lens again tomorrow to greater practical effect.

I have a powerful bunch grinder so it's easy for me to remove 1-2mm from the tube and I have loads of tubes, this one is the closest in length.

Eugen Mezei wrote:
You don't use it on a SLR? If yes than what you see in the mirrorbox will come to the film too.
If you have a splitscreen on the groundglass, than point to the moon. Should be far away enough to be considered infinity.


Yes, I use an EOS 10D but it doesn't have a split screen or any focussing aids so often things can appear to be close to focus in the vf but just be a blur when you look at the shots on the PC.

Eugen Mezei wrote:

On the very same site where the schematics you posted came from is another modification that does exactly the thing you mention.


Ah, thankyou, I find that site a little hard to follow but i will study it more closely. I happen to have a variable teleconverter that consists of a 2x teleconverter and a 20mm extension tube that can be fitted behind it. This tube has a metal insert inside it to reduce reflections that just happens to be the exact same diameter as the rear element of the Helios 44-2 so that is another modification I can do in seconds.

I wonder what would happen if I mounted an unmodified 44-2 on the tube with the rear element mounted in? That would be three symmetrical 116mm gauss groups in series.

Eugen Mezei wrote:
I think so.
Did the lens (or any other M42 lens) without the macro tube (I mean before the modification) focused to infinity with the adapter? Than you don't need to factor it in.


I think so to. Infinity is hit and miss with my various M42 lenses, they all will hit infinity but some focus past infinity, prime example being my Jupiter-11A. So I think the best approach is for me to go out and shoot some more tomorrow with the 18mm tube on the back and see how it works. Then if it doesn't hit infinity as we suspect it won't I can grind 1mm off the tube and test again. if still not hitting infinty remove another 1mm and keep trying until I remove enough that it does hit infinty.

This lens modding is really fun when the modifications are so easy, no dismantling of fiddly assemblies with tiny fiddly parts to loose or reassemble incorrectly, I think I will have to grab a few more cheap Helios 44-2s and make a whole range of modifications. It would be really fun to have a aluminium carry case containing a whole range of modified Helios 44-2s!

Last edited by iangreenhalgh1 on Sat Apr 02, 2011 4:01 am; edited 1 time in total


PostPosted: Fri Apr 01, 2011 10:21 pm    Post subject: Reply with quote
Well, It took about a minute to make a matching teleconverter for my modified lens by using the rear group of elements and a couple of M42 extension tubes.

The rear group of elements from the 44-2 fits perfectly inside this M42 tube:



However, it stick out the back by about 12mm, no chance of mounting on my camera, would hit the mirror:



But luckily I have a 10mm extension tube, screw that on the back and now the rear element protrudes less than 2mm and will miss the mirror by a mile:



This is the modified lens on the 18mm tube, ready to test tomorrow:



Here is the modified lens with the 'teleconverter' added:




Have to say, I'm delighted with this little project, cost in total is less than 10ukp. Just hope it will take some interesting shots when I test it tomorrow!


PostPosted: Sat Apr 02, 2011 8:47 pm    Post subject: Reply with quote
Right, the sun finally put in a long overdue appearance today so I took the modified lens out to take some more shots. I tried to recapture the swirly bokeh I saw in that one shot yesterday so most of these are wide open.

With the 18mm tube on the back it's much more practical to use but still won't hit infinity, it's a long way out in fact so shacing a mm or two off this tube probably won't work. I'll get a 14-15mm tube and try that and that should give me an idea what exact length it does need.

Anyways, I like the effects this lens now gives, especially wide open, it's definitely a modification worth trying as it does no damage to the lens and can be reversed in seconds by popping the rear group back in, just add a medium M42 tube et voila, an ersatz Helios-40 for a mere fraction of the cost.

Dof is shallow as hell so focussing skills are taxed and mine are crap but I'm getting better.

















PostPosted: Sat Apr 02, 2011 10:14 pm    Post subject: Reply with quote
There are some select spots in some of the pictures that suggest reasonably sharp focus can be achieved. To me it is looking much like the formidable Cyclop lens in the way it is behaving. If that is the case, results will depend much on how you use it - the subject, background, lighting, and exposure. Consider using in dim or shaded areas with uncluttered backgrounds when near. Underexpose by one full stop unless there is a bright lighted area, then two stops.


PostPosted: Sat Apr 02, 2011 10:23 pm    Post subject: Reply with quote
woodrim wrote:
There are some select spots in some of the pictures that suggest reasonably sharp focus can be achieved. To me it is looking much like the formidable Cyclop lens in the way it is behaving. If that is the case, results will depend much on how you use it - the subject, background, lighting, and exposure. Consider using in dim or shaded areas with uncluttered backgrounds when near. Underexpose by one full stop unless there is a bright lighted area, then two stops.


Cheers woodrim. I struggled to get the focussing right, going to require some practice with this lens to get the most out of it for sure.

I am absolutely delighted at how it performs, I have wanted a Cyklop since I saw the thread on them but they aren't that cheap.

I noticed the glow on bright areas so i did underexpose most of these shots then PP them. Thankyou for the tips on use, now spring has sprung here I will have plenty of opportunity for more practice with this lens, I'll post the best shots.

I'm keen to see if anyone else tries removing the rear element of a Helios-44 to try this for themselves, if anyone does, be sure to post up the pics!

Played around with some PP on a couple of the shots:





PostPosted: Sat Apr 02, 2011 11:35 pm    Post subject: Reply with quote
I've got a nice set of Hanimex tubes that are 22.5mm, 20mm and 11mm ( I presume the measurement is face to face and doesn't include the male thread ? ) and I have a couple off 44-2's, so I might try it in the next few days. The overall effect looks very interesting.


PostPosted: Sat Apr 02, 2011 11:52 pm    Post subject: Reply with quote
Lloydy wrote:
I've got a nice set of Hanimex tubes that are 22.5mm, 20mm and 11mm ( I presume the measurement is face to face and doesn't include the male thread ? ) and I have a couple off 44-2's, so I might try it in the next few days. The overall effect looks very interesting.


Yup, measurement doesn't include the male thread.

Good luck and would love to see your pics when you take some.


PostPosted: Fri Apr 29, 2011 7:46 pm    Post subject: Reply with quote
Any updates on this project? I'm in luck to have some "spare" Helioses and am thinking about converting one... Razz
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