Did I get a bad 35/1.4 Nokton SC?

[celluloidprop]

I've been trying to decide if what seemed like a lack of sharpness with my M4/35 Nokton SC was due to M4 issues, bad prints/scans from NorthCoast and Costco and with my V700. I couldn't really eliminate any of them as options. I picked up a 35/2 Biogon and my first set of cheapie prints from Costco were miles beyond anything I'd seen from the Nokton.

So I borrowed a NEX-5 (not 5N) and rented an adapter.

All of these are on a tripod, focused with the 14x magnifier, the slowest shutter speed was 1/30 (@ f/8). To my eyes, it's unacceptably sharp, roughly equal at f/5.6 or f/8 with the Biogon wide open - and that leaves me in a bit of a bind as I'm nervous about selling it on, and I'm quite a bit past the return period with CameraQuest.

Focus point was the wood at dead center. I know these are less than optimal conditions (budget NEX, etc.), but perhaps those in the know will say if it's in the acceptable range?

 

[celluloidprop]

Full image @ f/1.4 by celluloidpropaganda, on Flickr


100% crop @ f/1.4 by celluloidpropaganda, on Flickr


100% crop @ f/2 by celluloidpropaganda, on Flickr


100% crop @f/2.8 by celluloidpropaganda, on Flickr


100% crop @ f/4 by celluloidpropaganda, on Flickr


100% crop @ f/5.6 by celluloidpropaganda, on Flickr


100% crop @ f/8 by celluloidpropaganda, on Flickr

 

[celluloidprop]

The series I did immediately prior, before deciding that focusing on the point of the roof was a bad idea, but it exhibits the same behavior at each aperture.

All on tripod, shutter speeds fairly fast, 14x focus on the corner of the roof with red paint.


Full-size @ f/1.4 by celluloidpropaganda, on Flickr


100% crop @ f/1.4 by celluloidpropaganda, on Flickr


100% crop @ f/2 by celluloidpropaganda, on Flickr


100% crop @ f/2.8 by celluloidpropaganda, on Flickr


100% crop @ f/4 by celluloidpropaganda, on Flickr


100% crop @ f/5.6 by celluloidpropaganda, on Flickr


100% crop @ f/8 by celluloidpropaganda, on Flickr

 

[Chriscrawfordphoto]

That lens suffers from focus shift. That means if you focus it wide open, and stop down, the point of actually focus shifts BACK from what you focused on. Its a part of the lens's design, yours is just like all of them are.

 

[jordanstarr]

...your files are named DSC00068-73. I'm assuming it's the same range (f1.4 - f8) as the last set of tests. You may want to post the comparative results with the biogon. To me, the regular photograph looks fine and your magnification looks as sharp as my negative scans before sharpening, but I guess digital images should be sharper than scanned negatives?

Have you looked at larger prints to see how they match up with the same subject and aperture? Have you looked at the lens to see if it was tampered with (maybe someone opened up the lens to clean it and didn't fit it right back properly? loose glass elements?)

 

[celluloidprop]

Oops, didn't reload after I named each file in Flickr - edited with the aperture range.

I wondered about the focus shift when I was just getting prints back.
But at f/4, in the second series (roughly 15-20 feet away), I should have 10 feet of depth of field. That softness doesn't seem shift-related to me.

It was starting to drizzle outside, but I'll do a comparable series with the Biogon tomorrow, or find something here in the house to use tonight.

 

[celluloidprop]

Just ran a series from 5 ft away at a couple of DVD racks. I made a couple of changes to methodology (self-timer - I didn't think that could affect the outdoor photos since nothing was slower than 1/30, checking focus repeatedly at every aperture - there were slight shifts, and maybe I just couldn't tell where the sharpness plane had relocated on the second series up there) and I'm satisfied that it's plenty sharp. f/1.4 is a bit soft, but that's to be expected and would be flattering for portraits.

I need to get a dedicated 35mm scanner, the V700 makes it rather difficult to determine where sharpness issues lie or I probably could have figured it out before.

 

[Lflex]

Just ran a series from 5 ft away at a couple of DVD racks. I made a couple of changes to methodology (self-timer - I didn't think that could affect the outdoor photos since nothing was slower than 1/30, checking focus repeatedly at every aperture - there were slight shifts, and maybe I just couldn't tell where the sharpness plane had relocated on the second series up there) and I'm satisfied that it's plenty sharp. f/1.4 is a bit soft, but that's to be expected and would be flattering for portraits.

I need to get a dedicated 35mm scanner, the V700 makes it rather difficult to determine where sharpness issues lie or I probably could have figured it out before.

Sound reasonable. There were too many uncontrolled factors and problems with your method to make a firm conclusion.
You need to know your Nokton's flaws and work with/around them to enjoy this lens.

 

[uhoh7]

CV 35/1.4 MC on nex-5

full

full

Just some for you to compare. This is the sort of shot I test lenses with--to start with anyway. You can see right away how it's doing--especially if you compare to another lens like your biogon.

I would do some longer shots like this at f/8 with very careful focus--tripod if possible. Raw is better.

The biogon should be sharper, but as you can tell in the fulls--esp the second, the CV can produce sharp centers.

 

[jsrockit]

Shift shouldn't be an issue on a NEX, only on a mechanical rangefinder.

 

[Lflex]

Shift shouldn't be an issue on a NEX, only on a mechanical rangefinder.

If you focus wide open and stop down to shot, then you will have the shift issue.

 

[jsrockit]

If you focus wide open and stop down to shot, then you will have the shift issue.

But you will see the shift in your LCD, so you can refocus. With a rangefinder...you have to guess.

 

[Lflex]

But you will see the shift in your LCD, so you can refocus. With a rangefinder...you have to guess.

That's theory. In practice it is very difficult to notice on the LCD and it is quite challenging to re-focus precisely at say 5.6 or 8.0.

 

[Sparrow]

... surely stopped down to 5.6 or 8 any shift would be lost in the extra dof

 

[jsrockit]

That's theory. In practice it is very difficult to notice on the LCD and it is quite challenging to re-focus precisely at say 5.6 or 8.0.

So, are you saying all lenses are hard to focus at f/5.6 or f/8 on a Nex? I was under the impression that since, with a LCD, you see what you get ... focus shift should be a non-issue.

 

[Lflex]

... surely stopped down to 5.6 or 8 any shift would be lost in the extra dof

There is only one plane of focus. DOF depends of viewers distance and enlargement. If you pixel peak as we are doing in this thread you will experience that the sharpest place is not where you thought you focused.

In normal use and/or with film you probably will not be bothered at f 8, but at 5.6 at close distances or flat subjects you need to know your lens - not only the one mentioned here.

So, are you saying all lenses are hard to focus at f/5.6 or f/8 on a Nex?

I am saying stopped down lenses are harder to focus - The LCD is only a convenient approximation.

Michael Reichman's Nex 5n comment basically wraps it up:
Note that focus shift happens with some lenses, but not with others. There is therefore a trade-off to be made between the precision of focusing with a lens wide open, risking focus shift, and focusing closed down to shooting aperture, but with less accuracy due to increased DOF.

Read Reichman Nex 5n article and make sure to read Sean Reids addendum.