[frank]

How do the borders look like when you manually focus on the center of the paper?

 

Almost the same as focusing on the border. Please see the attached image.

 

Frank

[frank]

Hi Frank, some of the old lenses have aberrations in the center as they are not optimized for the light reflected from the sensor. Check Tom Hogan's website, he explains it in more technical terms... I don't have the exact link, sorry. I used to rent this lens before, but never notice the issue. My impressions are that the lens is sharp at f 2.8, but it shows purple fringing, which is quite visible.

 

Interesting point. But after searching the internet, I find that it seems sensor reflection occurs after the lens is stopped down. Please check http://thesybersite.com/minolta/sensor-reflection/ . But I will investigate it further.

 

Frank

[frank]

I have made some more tests, using a paper with white letters on a black background. When I tried to manually focus on the center of the paper to make the image of letters as clear as possible, I get the following image, where the letters have well defined boundaries but are imbedded in white halos:

 

[ATTACHMENT NOT FOUND]

 

I cannot judge if the "white halos" are caused by spherical abberrations, or by some kind of sensor reflection as suggested by borisbg.

 

On the other hand, if I try to reduce the "white halos" and get the "sharpest image without halos" by manually focussing the lens, I get the following image with blurry letters:

 

[ATTACHMENT NOT FOUND]

 

I don't even know if this can be considered as "in focus".

 

Again, the parameters are as follows: f=200mm, F=2.8, distance=1.6m (roughly).

 

Frank

[PuxaVida]

Hi again... Are you sure the 1.6m distance is ok with this lens? The closest focus distance is shown as 1.8m (1.5m at macro setting) on Nikon' s site . However, In fact this does not explain the issue. The previous samples were in focus but soft (as in very low contrast). Maybe the results are because of the sum of more than one issues (distance, aberrations, curvature etc...)

 

Serkan

[Brightcolours]

Tell me, how does the lens perform at other than close up distances?

[frank]

Hi again... Are you sure the 1.6m distance is ok with this lens? The closest focus distance is shown as 1.8m (1.5m at macro setting) on Nikon' s site . However, In fact this does not explain the issue. The previous samples were in focus but soft (as in very low contrast). Maybe the results are because of the sum of more than one issues (distance, aberrations, curvature etc...)

 

Serkan

 

Yes, 1.5m-1.8m is marked as macro distance (but there is no macro button), 1.8m-infinity is marked as macro distance. The lens has no problem from 3m to infinity, including the [email protected]. With my test, only in the distance range 1.5m-2.5m the lens is extremely soft at 200mm (indeed 150-200mm) and f2.8, the results in 80-150mm and f2.8 are indeed very good (indeed very sharp to my eyes). I heard the lens is soft at 200mm and f2.8 and close distance, but I didn't know it is so soft--which makes me wonder if this is normal for this lens or the lens is defected. If it is not defected, I want to understand what cause the pattern of the softness (clear letters imbedded in blurry halos): normal spherical abberation, reflection of the sensor, or something else?

 

Thanks,

Frank

[frank]

Tell me, how does the lens perform at other than close up distances?

 

I would say the lens performs excellent beyond a distance of 3m (sharpness wise). It is sharp even at 200mm and f2.8, at least I have no complain.

 

While for close up distance I only see the above sharpness problem for f=~150-200mm and f2.8.

 

Frank

[borisbg]

Frank, if you want to use it for close distances why don't put one extension tube and give it a try. I guess this lens is not meant for macro or near macro photography.

[frank]

Frank, if you want to use it for close distances why don't put one extension tube and give it a try. I guess this lens is not meant for macro or near macro photography.

 

Thanks, Borisbg. Yes, I know. I just didn't expect that the [email protected] is so soft for close up focusing, which made me think if the lens is defected.

 

Frank

[Brightcolours]

If the lens is fine at 3m and further, my guess is it is not defective. Just a design "issue" one sees at close focussing. Like boris says, an extension tube will allow you to get closer without getting into the trouble zone. a 12mm tube already will bring you within 3 meters while the lens is at infinity.