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Helios 44-2 58/2 back focus issue
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PostPosted: Tue Feb 28, 2012 8:10 pm    Post subject: Helios 44-2 58/2 back focus issue Reply with quote

I've been a lurker here for a while and though I've learnt a lot from reading the forums I'm a bit lost with this one.
I recently bought a Helios 44-2 58mm f2 from ebay and I've got an adapter from Big-is (M42-EOS). The adapter is the EMF AF confirmation type and what I've found is the lens is back-focusing quite a lot, in fact much more than my Canon 7D can rectify.
While 'messing about' I unscrewed the lens from the adapter by less than a half turn and the focus now seems about right and in synch with the audible/visual focus indicator. So should I try to fix the lens and adapter in place as they are or is there another solution I haven't thought of?


PostPosted: Tue Feb 28, 2012 8:30 pm    Post subject: Reply with quote

If it focus' correctly by unscrewing the lens, then maybe a paper / thin cardboard shim will do the trick ?

That's a great lens though, a perfect introduction to MF lenses.

I don't have experience with modern Canon, but I'm sure some who has will be along shortly.


PostPosted: Tue Feb 28, 2012 8:37 pm    Post subject: Reply with quote

the EMF chip has built in focus adjustment (so you can leave the camera setting on 0), but first i'd check the infinity setting. Turn the lens to infinity, and take a picture of something far enough away (50-100m) It should be tack sharp. If it is sharp before infinity, the adapter is a bit to thin. (i got some big_is adapters here, too and some seem to be about 0.01-0.05mm to thin)


PostPosted: Tue Feb 28, 2012 8:44 pm    Post subject: Reply with quote

spoilerhead wrote:
the EMF chip has built in focus adjustment (so you can leave the camera setting on 0), but first i'd check the infinity setting. Turn the lens to infinity, and take a picture of something far enough away (50-100m) It should be tack sharp. If it is sharp before infinity, the adapter is a bit to thin. (i got some big_is adapters here, too and some seem to be about 0.01-0.05mm to thin)


Ok I'll give that infinity test a try tomorrow when it's light.
I'd forgotten there was focus adjustment on the EMF chip because I've not needed it before now.


PostPosted: Wed Feb 29, 2012 8:20 am    Post subject: Reply with quote

spoilerhead wrote:
the EMF chip has built in focus adjustment (so you can leave the camera setting on 0), but first i'd check the infinity setting. Turn the lens to infinity, and take a picture of something far enough away (50-100m) It should be tack sharp. If it is sharp before infinity, the adapter is a bit to thin. (i got some big_is adapters here, too and some seem to be about 0.01-0.05mm to thin)


I would say it is the other way around. If the adapter is too thick, which is common unfortunately, the lens will never reach infinity focus. Thus the image is sharp before infinity (the thicker adapter acts as a tiny macro extension tube that moves the minimum (and maximum) focus position closer to the lens).

However, this shall not affect back or front focusing optically for the focus phase detection sensor and what you see in the WF. Correct me if I'm wrong, perhaps there is some special feature with the adapter you have and Canon that I'm not used to.

/T


PostPosted: Wed Feb 29, 2012 8:41 am    Post subject: Reply with quote

torbod wrote:
spoilerhead wrote:
the EMF chip has built in focus adjustment (so you can leave the camera setting on 0), but first i'd check the infinity setting. Turn the lens to infinity, and take a picture of something far enough away (50-100m) It should be tack sharp. If it is sharp before infinity, the adapter is a bit to thin. (i got some big_is adapters here, too and some seem to be about 0.01-0.05mm to thin)


I would say it is the other way around. If the adapter is too thick, which is common unfortunately, the lens will never reach infinity focus. Thus the image is sharp before infinity (the thicker adapter acts as a tiny macro extension tube that moves the minimum (and maximum) focus position closer to the lens).

However, this shall not affect back or front focusing optically for the focus phase detection sensor and what you see in the WF. Correct me if I'm wrong, perhaps there is some special feature with the adapter you have and Canon that I'm not used to.

/T


oh sorry, i actually ment to say "with the focus scale set to something before infinity", maybe that wasn't very clear Smile


PostPosted: Wed Feb 29, 2012 9:19 am    Post subject: Reply with quote

I've pretty much given up with AF confirmation; use live view for wider than F4 and you'll be fine.


PostPosted: Wed Feb 29, 2012 1:42 pm    Post subject: Reply with quote

So, I went out with the lens today and picked a subject around 80yds away and took two shots.
First shot is with the focus ring set to infinity and I got the AF confirmation bleep.
Second shot is with me focusing via live view, no AF confirmation bleep.
I then took two photos of the lens focus ring to show the difference between the two shots.
I hope that makes sense.


I have a few other mf lenses (see sig) all with adapters but they don't have this issue.
I know these images are small (don't know what I'm doing Rolling Eyes ) but it's clear I have a problem here . Sad
The question is what do I need to do to fix it?


PostPosted: Wed Feb 29, 2012 2:25 pm    Post subject: Reply with quote

martinsmith99 wrote:
I've pretty much given up with AF confirmation; use live view for wider than F4 and you'll be fine.

+1


PostPosted: Wed Feb 29, 2012 3:03 pm    Post subject: Reply with quote

SonicScot wrote:
So, I went out with the lens today and picked a subject around 80yds away and took two shots.
First shot is with the focus ring set to infinity and I got the AF confirmation bleep.
Second shot is with me focusing via live view, no AF confirmation bleep.
I then took two photos of the lens focus ring to show the difference between the two shots.
I hope that makes sense.


I have a few other mf lenses (see sig) all with adapters but they don't have this issue.
I know these images are small (don't know what I'm doing Rolling Eyes ) but it's clear I have a problem here . Sad
The question is what do I need to do to fix it?


I have had this issue many times with many lenses, i think it's the adapter being the wrong thickness.

Do you have another M42 lens you can try with the same adapter?

I have a Helios 44M4 and a big Is M42-EOS adapter, without AF confirm, if it will help I will take it out and see what results I get.


PostPosted: Wed Feb 29, 2012 4:16 pm    Post subject: Reply with quote

SonicScot wrote:
So, I went out with the lens today and picked a subject around 80yds away and took two shots.
First shot is with the focus ring set to infinity and I got the AF confirmation bleep.
Second shot is with me focusing via live view, no AF confirmation bleep.
I then took two photos of the lens focus ring to show the difference between the two shots.
I hope that makes sense.


I have a few other mf lenses (see sig) all with adapters but they don't have this issue.
I know these images are small (don't know what I'm doing Rolling Eyes ) but it's clear I have a problem here . Sad
The question is what do I need to do to fix it?




Hi, this is not an issue...it´s pretty normal behaviour. You can´t trust the AF confirmation at all. If you can get a sharp image with live view so there is nothing wrong with your lens.


PostPosted: Wed Feb 29, 2012 5:00 pm    Post subject: Reply with quote

Yes, I'm sure the lens is fine, I've had at least 10 Helios 44s and they were all fine. The issue is the adapter thickness.


PostPosted: Wed Feb 29, 2012 5:38 pm    Post subject: Reply with quote

Thanks everyone for your replies.
I didn't actually think there was anything wrong with the lens as such, I was just hoping to match the AF confirmation with having an in-focus image. I can live without this by using the live view, as people here have suggested, it's just that live view isn't always ideal in a given situation.
The adapter was only about £6 so I might as well get another from a different seller and see if that has a more appropriate thickness.

I bought the lens after reading the many Helios posts here, it's in great condition and only cost £11. I 'think' it's the KMZ version, maybe someone could confirm this. The coloured lettering and serial number starting with 74 makes me think it is.

Again, thanks for the help. Very Happy


PostPosted: Wed Feb 29, 2012 5:40 pm    Post subject: Reply with quote

iangreenhalgh1 wrote:
SonicScot wrote:
So, I went out with the lens today and picked a subject around 80yds away and took two shots.
First shot is with the focus ring set to infinity and I got the AF confirmation bleep.
Second shot is with me focusing via live view, no AF confirmation bleep.
I then took two photos of the lens focus ring to show the difference between the two shots.
I hope that makes sense.


I have a few other mf lenses (see sig) all with adapters but they don't have this issue.
I know these images are small (don't know what I'm doing Rolling Eyes ) but it's clear I have a problem here . Sad
The question is what do I need to do to fix it?


I have had this issue many times with many lenses, i think it's the adapter being the wrong thickness.

Do you have another M42 lens you can try with the same adapter?

I have a Helios 44M4 and a big Is M42-EOS adapter, without AF confirm, if it will help I will take it out and see what results I get.

I don't have another adapter at the moment but I'll order one today.


PostPosted: Wed Feb 29, 2012 9:35 pm    Post subject: Reply with quote

Don´t be dissapointed with you next adapter...if you are able to get a sharp image with live view so there is no problem with you adapter...it´s juts the inaccuracy of the AF confirm...look here how many people here are dealing with split-screen and microprismatic third-party focusing screens. If the AF worked precise noone would need them Smile Or ?


PostPosted: Thu Mar 01, 2012 1:40 am    Post subject: Reply with quote

I think all my adapted lenses focus before the infinity mark no mater which mount or adapter.


PostPosted: Thu Mar 01, 2012 7:07 am    Post subject: Reply with quote

revers wrote:
I think all my adapted lenses focus before the infinity mark no matter which mount or adapter.
I think the dozen or so adapters I have are the same. Better to go past infinity than stop short of it I suppose.


PostPosted: Thu Mar 01, 2012 3:21 pm    Post subject: Reply with quote

martinsmith99 wrote:
revers wrote:
I think all my adapted lenses focus before the infinity mark no matter which mount or adapter.
I think the dozen or so adapters I have are the same. Better to go past infinity than stop short of it I suppose.


Just trot out the excuse the AF peeps use for going past infinity... it's to allow for temperature variation. Wink Might as well make something positive of the situation!

K.


PostPosted: Thu Mar 01, 2012 3:27 pm    Post subject: Reply with quote

martinsmith99 wrote:
revers wrote:
I think all my adapted lenses focus before the infinity mark no matter which mount or adapter.
I think the dozen or so adapters I have are the same. Better to go past infinity than stop short of it I suppose.


Most adapter maker doing on this way due safest , than make an accurate adapter and buyer send it back due not reach infinity sometimes with a lens.

I have accurate adapters for Samsung NX (Kiwi) and reach before infinity (Pixco ) to SONY NEX.


PostPosted: Thu Mar 01, 2012 3:37 pm    Post subject: Reply with quote

Attila wrote:

Most adapter maker doing on this way due safest , than make an accurate adapter and buyer send it back due not reach infinity sometimes with a lens.


I can see the sense in that.


PostPosted: Tue Mar 13, 2012 5:40 pm    Post subject: Reply with quote

SonicScot wrote:

The adapter was only about £6 so I might as well get another from a different seller and see if that has a more appropriate thickness.
Very Happy


Update: I ordered another cheap (£7.50) M42-EOS adapter from China (different seller) and this one is clearly a different thickness. The AF confirmation turns out to be accurate this time...ok I had to make a 7-point micro adjustment. Wink
Obviously I'll use live-view most of the time to really nail focus but it's good to know I can shoot on the fly and be there or thereabouts. Very Happy

This seller was Adplo Camera accessory Shop, in case anyone wants to know.


PostPosted: Wed Mar 14, 2012 10:52 am    Post subject: Reply with quote

SonicScot wrote:
The AF confirmation turns out to be accurate this time...ok I had to make a 7-point micro adjustment.


try to reach the focus plane from far and from close, and you may perhaps change idea Wink .


PostPosted: Wed Mar 14, 2012 9:50 pm    Post subject: Reply with quote

Attila wrote:
martinsmith99 wrote:
revers wrote:
I think all my adapted lenses focus before the infinity mark no matter which mount or adapter.
I think the dozen or so adapters I have are the same. Better to go past infinity than stop short of it I suppose.


Most adapter maker doing on this way due safest , than make an accurate adapter and buyer send it back due not reach infinity sometimes with a lens.


I wish that was the case with both my MFT adapters for LTM and M42, but my lenses cannot focus to infinity on them. And they're from different sellers too.