50mm Leica-M Summilux ASPH

[lct]

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Mine is 6 bit as well. Got an overhaul at Wetzlar last year.

[jaapv]

I set the focus all at the same and only adjust the shutter speed and aperture.

which F1.4 do u mean, Centre or Corner or both?

 

 

 

The focus area was at the left side "ball knob" not the part that curve in.

I was using SL manual focus using the Live view, I think it can't be front focus issue right?

Well, if you look to the right in the centre shot crop you can see that the knotted strings on the right are in the plane of focus and that the part that you focused on is not.

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[turbonetics]

Well, if you look to the right in the centre shot crop you can see that the knotted strings on the right are in the plane of focus and that the part that you focused on is not.

 

 

I think the materials plays a part?

the place I focus on has more fine thread and that was the reason I choose to judge the details/sharpness.

I think maybe I should send it down for professionals to check.

Edited April 25, 2016 by turbonetics

[turbonetics]

Mine is 6 bit as well. Got an overhaul at Wetzlar last year.

 

why did u send for overhaul?

and do u see any difference? in which aspects?

 

Thanks.

[lct]

why did u send for overhaul?

and do u see any difference? in which aspects?

 

I just dropped the lens which caused some back focus and asked Leica to do a 6-bit coding and fix the stiffness of the focus ring at the time. Took them 6+ months to do the job but the lens works perfectly now.

Edited April 25, 2016 by lct

[jaapv]

I think the materials plays a part?

the place I focus on has more fine thread and that was the reason I choose to judge the details/sharpness.

I think maybe I should send it down for professionals to check.

You might do so, as the floating elements mechanism is made to exceedingly narrow tolerances and is a known weakness of the lens.

[Rick]

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The 50 Summilux is actually one of the best performers at the edge of the frame.  The Summilux 50 1.4 is actually an APO design according to Peter Karbe.  It is probably the best all-around 50 ever made.

 

The edge performance of the lens has been reported to resolve 1368 lp.  The same as the 50/2 APO!

 

The 50/2 APO has better field curvature and has been reported to resolve 1368 lp in the middle of the frame where the 50/1.4 resolves 1152 lp.

 

At center the 50/2 continues to excel and is reported to resolve 1680 lp vs 1488 lp for the 50/14.  Nothing touches the 50/2 APO for sharpness across the full frame.

 

But, the edge performance of the 50/14 exceeds both the Zeiss Otus/1.4 and the Sigma Art/1.4 - Both newer designs for digital.

 

*All tests done at f2.0.  All lenses here would fall of some at f1.4, of course.

 

Rick

[harmen]

If you take a picture of something that is positioned at an angle you can always find something that is in focus. Take a page of a book for example and then see if text near the edge of the photo is any worse than text in the center. Just don't take it full frontal. Good luck!

[Mornnb]

It looks as if your object is ever so slightly behind the plane of focus.  The tassels that extend towards the camera seem sharper.  Or is it me?  How about taking a shot where your object is angled 45 degrees so you avoid any focus issues?

 

Which is likely focus shift, the plane of focus of the lens bends towards the edges of the frame, the problem is the rangefinder does not account for this field curvature. It actual use situations this is an issue, for example consider taking portrait orientated photos of people. You focus in the centre with the rangefinder, recompose so that the persons face is near the lines of thirds and the focus is thrown slightly off by field curvature.

To avoid this, one needs to go with the more corrected 50mm APO. It is a good argument in favour of the APO.

Edited May 1, 2016 by Mornnb

[lct]

The 50/1.4 asph has some field curvature like most lenses besides exceptional ones like 50/2 apo but none of them has the least focus shift, as far as my copies are concerned at least.

[Mornnb]

The 50/1.4 asph has some field curvature like most lenses besides exceptional ones like 50/2 apo but none of them has the least focus shift, as far as my copies are concerned at least.

 

 

Sorry, when I said focus shift, I actually meant field curvature. While I absolutely love the rendering of the 50mm Lux which is essentially perfect (IMHO it's better than the Noctilux at 1.4). The field curvature has meant I have missed a few shots at f1.4 when doing a focus and recompose.

 

 

There's an article here that shows a clear example of it, note the comparison between centre focused and edge focused.

http://3d-kraft.com/index.php?option=com_content&view=article&id=160%3Aadorable-50s-sigma-art-zeiss-otus-sonnar-leica-summilux-review&catid=40%3Acamerasandlenses&Itemid=2&limitstart=4

Edited May 2, 2016 by Mornnb

[lct]

Well known issue at fast apertures. A modern EVF with moving focus patch is the best if not the faster solution.

[IkarusJohn]

The 50/1.4 asph has some field curvature like most lenses besides exceptional ones like 50/2 apo but none of them has the least focus shift, as far as my copies are concerned at least.

 

 

Looks like field curvature to me too.

 

The best test would be to use the SL, focus using the magnifier on something in the corner (as LCT has done above), and be very sure what you've focused on.  At f/1.4, the depth of field at 1 metre focusing distance is only 7mm ...

[james.liam]

The 50/1.4 asph has some field curvature like most lenses besides exceptional ones like 50/2 apo but none of them has the least focus shift, as far as my copies are concerned at least.

 

Lloyd Chambers managed to demonstrate the slightest bit of shift on the 50 APO at very close distances. Unknown if this applies to subjects at distance. Matters are even more dramatic with the MM and red filters (maybe why Leica isn't making 39mm reds) but also to a lesser degree with orange.

 

Some shift is also hinted at for the 50 Summilux too based on the MTF graphs but don't want to give away all of Lloyd's findings.

 

All in all, seems marginal/minimal at worst for both.

Edited May 3, 2016 by james.liam

[lct]

Looks like Mr Chambers sees focus shift everywhere more or less. Last time was on the 28/2 v2 if memory serves. I posponed my order because of that but serious owners i trust have reassured me so i have ordered the lens finally. I've not yet received the lens but i don't hold my breath. As far as 50/1.4 asph and 50/2 apo are concerned, i've never seen the least hint of focus shift at 0.5 metre and on but i'm not a notorious reviewer.

Edited May 3, 2016 by lct

[james.liam]

Looks like Mr Chambers sees focus shift everywhere more or less. Last time was on the 28/2 v2 if memory serves. I posponed my order because of that but serious owners i trust have reassured me so i have ordered the lens finally. I've not yet received the lens but i don't hold my breath. As far as 50/1.4 asph and 50/2 apo are concerned, i've never seen the least hint of focus shift at 0.5 metre and on but i'm not a notorious reviewer.

 

Sean Reid, perhaps less notorious but equally as thorough, notes a shift in the new 28/2 as in the old, as well as the retired 35/2 asph--I know you did not, but this may all be subject distance-dependent.

[lct]

I don't read reviews about lenses i own but what you're saying doesn't encourage me to change my mind i must say.

[james.liam]

I don't read reviews about lenses i own but what you're saying doesn't encourage me to change my mind i must say.

 

 

Not my place to do any of that.

Some seek opinions, others leap on faith. We all deal with the consequences accordingly. Each to her/his own comfort level. 

[lct]

I'm more interested by facts than by opinions or faith personally but i'm always glad to share others' experience on this great forum.

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.... The field curvature has meant I have missed a few shots at f1.4 when doing a focus and recompose.....

The loss of focus with focus and recompose is caused by turning the camera away from the spot you focused on. It's a merely geometrical effect and happens even with a theoretically ideal lens, i.e. with a lens which does not suffer from any field curvature.

 

When focusing, you measure the distance of your target from the focal plane. When you recompose, you turn the focal plane. The target will now lie on a plane which is parallel to the focal plane but much closer than the target was when focusing.