28mm Summicron-M ASPH: Edge Softness Issue

[aaron_johnston]

I recently purchased a 28mm Summicron-M ASPH lens used and looked over

my first slides taken with it (Fuji Provia 400f/Leica M7.) At any

rate, I notice a lot of edge softness and am somewhat surprised by the

results as this was not a major issue in any of the reviews I read.

The glass looks very clean and I bought it from a reputable dealer.

 

Can someone else with experience using this lens tell me if they have

experienced similar problems?

[OCULUS New York]

No such experience with mine for past 2 years.

 

<img src=http://d6d2h4gfvy8t8.cloudfront.net/2202124-lg.jpg>

 

Good luck,

ray hull

[erudolph]

Sorry for making this big but if it's not big you can't see. This was shot at f/5.6 I think.

 

 

<center><img src="http://d6d2h4gfvy8t8.cloudfront.net/4222132-lg.jpg"></center>

 

<center>28mm summicron</center>

[eliot_rosen1]

In my experience, the edge sharpness of the 28/2 Summicron is about as good as it gets for a 28 mm lens. It consistently gives outstanding results. Maybe you could post an example showing the edge softness, so we can see what you are talking about.

[stuart_richardson]

How are you checking the edge sharpness? If you are scanning, often the edges go soft if you

are not using a glass mount. Even regular slide mounts can make the edges appear soft when

projected, or if you look at them with a loupe that is not centered over the edge. If it is soft

at the edges and it is not a depth of field issue, then perhaps your body or lens need to be

adjusted. This is the least likely case. Though I don't have the 28/2 ASPH, I would doubt that

it would have any significant softness when stopped down even a bit. Chances are the

problem is somewhere else in your image chain.

[eliot_rosen1]

I find that even at F/2 it is quite sharp at the edges. As far as I have observed, the only flaw of this lens is that it has more vignetting at large apertures than I would like to see.

[aaron_johnston]

Thanks, everyone. I am beginning to suspect my Nikon 500ED film scanner may have a part in it. I do not have a loupe or a light table (I shoot negatives 90% of the time) and I cannot notice the edge softness quite as much as I do on screen. Still, I will fiddle with it some more.

 

I think my major concern was the fear I had a bad lens but edge softness does not seem a likely byproduct of sample variation and the glass looks fine.

[stuart_richardson]

Well, I don't know if the Nikon lets you set the focus point, but if it does, set it for the corner

and see if it comes out sharp. My experience with this type of scanner is that you cannot get

edge to edge sharpness unless you use glass mounting. This is the claim to fame of Imacons

and drum scanners...they can get edge to edge sharpness.

[stuart_richardson]

Oh, and you can improvise quite a good loupe by opening a blank white page on your

computer (in the browser for example), and take a 50mm lens (summicron/planar/

nokton...whatever) and look through it. As long as you can open the lens completely, it can

be used as quite a good loupe.

[david-m]

I have found my 28 cron to be absolutely sharp from centre to edge, and even wide open it

is still pretty astonishing. This is my most used and favoutire lens. The Nikon 5000

scanner will allow you to selectively focus wherever you want, so check it this way.

 

David

[robert_clark]

Much better and easier to check on a light box with a good loupe. Make sure you centre over the edge or corner.

[arthuryeo]

>This is the claim to fame of Imacons and drum scanners...they can get edge to edge sharpness.

 

Just to interject: you do not need to spend $10K for a glass-mounted scanner. The Nikon Super Coolscan 9000ED already has it. And, soon, the new Epson 6400ppi scanner will even allow you to do liquid-mounted scans, if you're that much motivated.

[stuart_richardson]

Arthur -- my comments about glass were not about the Imacons or drum scanners -- neither

of them use glass. I was talking about the traditional film scanners like the Minolta Scan Multi

Pro, which is even cheaper than the 9000ED, and most people seem to think it is better as

well, but that is another argument. Imacons and drum scanners are famous for edge to edge

sharpness because they bend the film, and I was saying that if he wanted to get a similar

effect he would need to use glass mounts. If you are scanning mounted slides, you can buy

Gepe anti-newton glass slides to replicate the effect, even without buying a more expensive

scanner like the 9000 ED or Scan Multi Pro.