Dud new 35mm 1.4

[tashley]

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So as I mentioned in my Venice thread, I took delivery of my discount offer by getting the 35mm 1.4 APO ASPH. It arrived the day before I went to Venice and I used it a lot the first day, but as I chimped away, I realised it was soft. At first I thought that since my M8 had been away I'd lost the RF focus knack, then I thought maybe Solms had nudged the RF into backfocus. But a process of elimination by controlled shooting in comparison to other lenses has proved to my satisfaction that for whatever bizarre reason, the lens is soft in the centre and sharp at the edge, and that this is the case at all apertures.

 

I won't post every exhaustive test but this series is very indicative. So my questions are:

1) Has anyone else seen this?

2) Please tell me it's not a characteristic of this lens ;-) ... ;-(

3) Do we think that QC at Leica has slipped due to their recent stresses and strains?

4) Do people who own correctly functioning versions of this lens find it as sharp as the 50mm 'lux?

 

Thanks for any advice or thoughts you might have!

 

Methodology:

 

Part of a wider test using other lenses and apertures. These shots were taken at f4, on a tripod, at 1/500th ISO 160. I show first the whole image downsized so you 'get the picture' then I show 100% crops from centre and edge. All from the 35mm Lux. Then finally there's a shot of the centr crop as produced under identical conditions from the 50mm 'lux, but before cropping I downsized to 70% so as to deliver the same resolution as the 35mm lens:

 

Full scene:

[ATTACH]25626[/ATTACH]

 

100% crop from centre:[ATTACH]25627[/ATTACH] 100% crop from edge: [ATTACH]25628[/ATTACH]

 

Centre crop from 50mm lux:

[ATTACH]25629[/ATTACH]

[Guest guy_mancuso]

Tim just got home from a shoot , looks to me like a floating element is out of whack. Rare yes but can happen. Just for grins find a intersection of a sidewalk with four lines and wide open focus on the middle of it at around a 45 degree angle. Lets see where the center focas falls. Looks like it will front focus

[sdai]

I don't think there's a floating element in the 35 Summilux ASPH ... back focus may be the case. Definitely send it in for a check.

[Guest guy_mancuso]

Hmmm I thought the asph element was floating but could be wrong on this but still looks like a element out of whack

[cnguyen]

I personnaly don't think it's a good test image. You camera digital film plane is not parallel to the building facade - looks like you're tilting the camera upward. Why not do a brick wall test with both of your 50mm and 35mm f1.4 again and go from there.

[tashley]

I personnaly don't think it's a good test image. You camera digital film plane is not parallel to the building facade - looks like you're tilting the camera upward. Why not do a brick wall test with both of your 50mm and 35mm f1.4 again and go from there.

I get your point but I have to say that the degree of tilt is the same at the centre as at the edge and is the same for the 50mm and the 35mm... more likely as an alternative is that the lens is back focusing and that the distance to the edge is greater so the focus is correct there BUT I can't get ANY shots under any circumstances that are sharp in the centre. Not one!

 

Tim

[cbretteville]

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Hmmm I thought the asph element was floating but could be wrong on this but still looks like a element out of whack

 

The 50 'lux and 75 'cron each have a floating element. The 35 'lux ASPH does not.

 

- C

[Guest guy_mancuso]

Thanks Carl , i must have been confused on the 35mm

[AlanG]

Clearly the lens has a problem. The angle of tilt won't have much to do with the center to edge situation. There is no doubt that you should be getting better results than that as the resolution is about the same as I get with a tiny 7 megapixel p&s. You should return the lens.

 

Here's a similar image to compare:

 

http://goldsteinphoto.com/venicedetail.jpg

 

I was in Venice just before the Carnival.

[tashley]

Clearly the lens has a problem. The angle of tilt won't have much to do with the center to edge situation. There is no doubt that you should be getting better results than that as the resolution is about the same as I get with a tiny 7 megapixel p&s. You should return the lens.

 

Here's a similar image to compare:

 

http://goldsteinphoto.com/venicedetail.jpg

 

I was in Venice just before the Carnival.

Thanks Alan - I am sure you're right. The only problem is that I need it back in 9 days for another trip and... well, you know Solms...

 

;-(

 

Tim

[tashley]

Tim just got home from a shoot , looks to me like a floating element is out of whack. Rare yes but can happen. Just for grins find a intersection of a sidewalk with four lines and wide open focus on the middle of it at around a 45 degree angle. Lets see where the center focas falls. Looks like it will front focus

 

Thanks Guy, I'll give that a try, though by now I'm pretty convinced that this lens is screwed, and not in a filter thread sort of a way!

 

Tim