helios 44m soft from midframe

[sonics]

From my grandpa's lens collection the most known one is a helios 44m sticked on a zenith camera.

On my 5D I use a tokina 17mm rmc f/3.5 and a CZ distagon 28mm f/2.8. Both met my expectations.

The helios however showed realy soft from midframe to border on my 5D. Worst wideopen only getting real sharp at f/11 at the corners.

My plan however is to use this lens on a sony nex, so I tried the helios on the nex.

For portraits the lens is fine but also on the nex the helios is not sharp near the borders up to f/8

Is this normal for this lens or is this a bad copy? The adapters I use are cheap china ones but I don't think that can be the cause.

tnx,

[Olivier]

[Attila]

Welcome! Your lens has faulty, hundreds of Helios user here and they are happy with their lens, buy another lens, I think less cost than get this one fixed.

[Lloydy]

All five of my Helios are sharp, I love them. Post some pictures taken with it, the problem might be simple to put right.

[sonics]

Hi there,

tnx for the reply. I post 3 examples of what I mean. All were taken at f/2.8



this one is from a sony nex at f/2.8



... and this one from a Canon 5D



When doing portraits the lens seems to do fine because borders are blurred anyways. Made with the sony nex

I also made some landscape photos which I deleted at f/4 and f/5.6 on my 5D which showed also border softness but less than here.

[Lightshow]

Looks soft to me, decentered(or loose) or maybe an element is in backwards.
Here's a WO shot from my KMZ 44-2 on my 1DIII

[Olivier]

[sonics]

Can I fix that myself? Or better to buy another one?

[Olivier]

First of all, try by yourself.

Remove the front ring with the helios name using a lens wrench.
Then you'll be able to pop glass out, clean it and reassemble it. Maybe this operation should realign the glass and solve the problem.
If not, try to remove the back glass by using the spanner wrench again, unmount, clean and remount the rear glass.

[Lightshow]

The 2nd group below the line is the design layout of the 44, just make sure they are mounted correctly, the rear is the easiest to get backwards.
http://www.abload.de/img/lens_scheme_dg_v2k8hu.png
From: http://forum.mflenses.com/list-of-lens-diagrams-triplets-planars-and-hybrid-lenses-t22934.html

[Lloydy]

It's worth a try, they are robust so can be dismantled fairly easily. And they are cheap if it all goes wrong.

I've got an excellent set of instructions but they are in PDF format - I'll sort them out tomorrow and post them here.

[Lightshow]

Helios lenses are great lenses to learn how to work on lenses, they're relatively simple, and somewhat cheap and fairly common so not a big deal if you have an oops.

[sonics]

[Ultron]

Left and right seem equally soft to me. And the Helios is known to have soft corners wide open.
But your corners look softer then I would expect so maybe an element has been reversed. I would try turning them around.

[sonics]

I bought another 44m and 44-2 for cheap and did some testing.

I liked the 44-2 best in handling and feel; smooth focusring and stop-down ring.
Too bad the mirror will lock at infinity on my 5D but for portrait and close distance this is not a problem. I want to use it on my nex as well.




The top two are from the 44-2 with different focus points. Can I conlude that this lens suffers from field curvature?

The 44m shows me there is quite some sample variation. The new sample I bought is better around the borders but less good in the centre at f/2.8. I tried the lens outside at infinity distance and showed the same results. The new 44m sample achieves same centre sharpness as the rest at around f/5.