Field curvature on 50mm 1.4 Summilux ASPH?

[IronLion]

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A quick update- I haven't had time to take more test shots unfortunately. I'm waiting for some time to take outdoor shots in decent light, but I have been too busy at work to get home in time to take daylight shots. Later in this week should clear up though and I'll post test shots here soon after I can take them.

 

In the meantime though, I did look through my shots from this past weekend and found another one that seemed, well, odd to me, and odd in the exact same way as the first photo that I posted. In this shot, I again chose to focus on a street sign out of boredom- it was probably about 15-20 feet away from me, and again, for some reason that looks and feels weird to me, the area in the upper left hand corner, which is clearly further than the stop sign (I double-checked this the other night when I passed it) appears to still be significantly sharper/more in focus than I would have expected. I saved this one from Photoshop without using the "Save for web" option, so hopefully the exif data is attached for those who are interested in it. 

 

 

For my future test shots, I've been looking for a decent 35mm lens for indoor use, and given the recent weirdness I've experienced with my 50 Summilux ASPH, I figured snagging another lens sooner rather than later would help determine definitively that the issue lies with the lens and not with my new M10. So, tomorrow I should be receiving a used 35mm Zeiss Biogon that I purchased off of the FM forums which will hopefully help me to diagnose the issue. 

 

Thanks to everyone for chiming in with additional thoughts- I hope to post here again soon with some test photos for people to help me make sense of what is going on. 

[Fgcm]

Dear IronLion,

this tread is very interesting. In the week end I will check my Summilux Asph and I will be back to you with some DNG to compare with yours.

Ciao

Franco

[lct]

Your focus point is too close to be compared to IronLion's Franco.

[Fgcm]

Ict, I agree with you.

I edited my previous post.

In the week end I will deeper investigate the problem.

[IronLion]

Dear IronLion,

this tread is very interesting. In the week end I will check my Summilux Asph and I will be back to you with some DNG to compare with yours.

Ciao

Franco

 

Thanks so much Franco! I really appreciate it.

 

This is by a wide margin the most expensive lens that I have purchased, so a point of comparison would be really great to have.

[tobey bilek]

On the next series,  do a focus bracket and do not focus and recompose.    

 

Interesting thing on last pic is the silver car seems to be be in good focus,  yet the sign at same distance is not.

 

I am beginning to think this lens needs to go back to seller.  It is screwed up and may or may not be fixable.   Used lenses have histories you can not know and I would not waste much time on it.

[jaapv]

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Everything is fixable - but this is a lens that is very "difficult" mechanically and even new ones have to go back to the factory from time to time to be reworked.

 

In your case I would certainly return it. Even if your doubts should be unfounded (although I suspect they are real), there will always be that nagging feeling in the back of your head.

[250swb]

With such baffling phenomena my instinct is to shake it and listen for any rattles or clonks. You could also twist it and pull it. Also look at it, aperture blades clean and all symmetrical and working, any signs it has been taken apart in the past? 

[tobey bilek]

Everything is fixable - but this is a lens that is very "difficult" mechanically and even new ones have to go back to the factory from time to time to be reworked.

 

In your case I would certainly return it. Even if your doubts should be unfounded (although I suspect they are real), there will always be that nagging feeling in the back of your head.

 

Probably but what is the cost and who pays.  Hours & hours might be spent if it was assembled wrong or with parts from two different lenses. 

 

If this were a car here in USA , paint it yellow and call it a lemon.  I have a few CV early lenses I will never sell as they are my favorite paperweights.  

 

A screwed up lens is the seller responsibility if he is a decent seller.  Buyer deserves a different lens or refund.  

[Fgcm]

Dear IronLion,

before discussing the problem of your Summilux, I wish to point out that f1,4 lenses are not designed for maximum sharpness (whatever it means).

Fast lenses are a mix of acutance, smooth bokeh and gorgeous colors.

 

If you take a photo of a traffic plate shooting from your bow window ad medium distances, you are building the perfect storm.

This is the worst possible senario for a Summilux 50 Asph or any other fast lens.

 

To clear your doubts about your lens, you should perform some meaningful tests.

 

First test is a photo of something very far away, not 100 feet, much more. 

This is a good example of long distance:

 

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View of Sydney from the Opera House. Handheld (thanks to the Summilux at f1,4  ) 

 

As you see, the centre si sharp, but at the edges, the photo is's not perfect.

This is normal with a Summilux 50 asph a f1,4 and, believe me, this is the best f1,4 ever.

 

If you want a sharper image, stop down to 5,6 or go for a Summicron or a Planar, but forget the character of this great lens.

 

If you look for the best colors, Summilux 50 Asph is the absolute winner

The second check is a photo at short distance (5 - 10 feet) of a colorful subject at f1,4. If necessary, use a neutral density filter.

 

 

Piazza Duomo, Origia Island, Siracusa, Sicily

I think colors of this photo do not need any comment.

Bokeh is smooth.

 

The last check: the lens must show good acutance and micro contrast in the center.

 

 

Cortona, Tuscany. 

Look at the dress. The image is crisp, colors are vivid, you can see the texture of the dress.

 

This is what you should expect from your Summilux, so, go out shooting real people and real things and check the result at a normal size, not at 100% view.

 

If you get colorful images, good acutance and micro contrast, smooth bokeh your lens should be fine. 

 

Let's go back to the apparent field curvature of your lens.

I went out for a traffic plate with something behind at some distance and I got the same weird field curvature as yours.

Apparently you are the first to report this weird thing.

 

 

Look at the crop of the right corner.

It is too far to be on the focus plane, nonetheless it's pretty sharp.

 

 

I was closer to the plate than you were when you took your photo, so I got a sharp image of a closer corner.

If you want, you can check yourself the problem changing the distance from the plate outside of your window.

 

I repeat: you got the worst possible senario to test your lens. If you were closer or farther from the plate, the roof of the house would not be sharp. I cannot say if this is bad luck or the contrary.

 

Do not forget that this is one of the last Leica lenses designed at the end of the film area, without a 0,8 mm infrared filter between the lens and the sensor. 

On the Adox CMS 20 film, Summilux 50 asph performs very very well. IMO, even better than on digital.

 

Now that I'm aware of this field curvature at medium distances, I'm still very very happy with my Summilux, which has taken so many beautiful photos in the years.

 

Ciao

Franco

 

 

 

 

 

 

 

[pico]

if you choose "save for the web" EXIF will be stripped.

 

Best to allow all metadata. Middle right side of Save for Web dialog.

[John Black]

 

Double Images in the background with a Summilux 50 Asph? Really?

 

 

 

Yes, towards the edges of the frame and extreme corners.