AF 20mm 2.8D lens misalignment?


Status
Not open for further replies.

kwanhan

Senior Member
Aug 17, 2009
828
2
18
37
Redhill
Hi guys, is this a case of lens misalignment?

Look at the left most 1/8 of the frame, the entire vertical strip.

D300, ISO400, f2.8, 1/60 (getting this in prep for FX upgrade)

8263582032_880c8697e5_o.jpg


view it larger on flickr: http://www.flickr.com/photos/kwanhan/8263582032/sizes/o/in/photostream/

I've heard that misalignments are hard to fix and even after calibration the blurriness could be fixed but the sharpness overall could be affected.
 

Last edited:
Seems like there is a drop in focus at the top right corner and its affects more than 1/8 of the frame. If you are not comfortable with it, look for something else.
 

Seems like there is a drop in focus at the top right corner and its affects more than 1/8 of the frame. If you are not comfortable with it, look for something else.

the context is that i've already bought it 2nd hand from The Camera Workshop... lesson learnt that I got to be more thorough in my checking (so far I've been lucky with my 2nd hand purchases)

Thankfully TCW is honouring their warranty and will let their technician have a look- in the event that it can't be fixed they are willing to let me have an equivalent value swop (either another 20mm copy if there's one in the shop, if not i'll upgrade my 85 1.8D to the G)
 

I believe that it's the property of the lens. The 20mm f/2.8D lens have poor performance at the corner/borders. It will be worse if it's on a FX camera. It only gets slightly better when stopped down to f/5.6 and narrower. Like bro Kit advised, if you're not comfortable and need better corner performance, look for something else.
 

I believe that it's the property of the lens. The 20mm f/2.8D lens have poor performance at the corner/borders. It will be worse if it's on a FX camera. It only gets slightly better when stopped down to f/5.6 and narrower. Like bro Kit advised, if you're not comfortable and need better corner performance, look for something else.

stopped down (to f8) it still looks unacceptably mushy (not in a distortion way) which is why I'm thinking it isn't a property of the lens but either a bad copy or misalignment.

(a friend's copy i handled previously was less sharp but no corner problems this noticeable)

if it was lens property, the corners would be equally bad throughout? I'm not sure about this.

but yes the 85 1.8g swop is an option.. will update on how it goes
 

Are you able to crop down to the affected portion? There are many variables but if a lens is weak in resolving the corners, it should be quite uniform throughout. I've studied the image, it doesn't seemed to be depth of field issue since the boxes are more or less placed at the same distance from the lens and you are standing close to parallel to the subjects.

On a side note, barrel distortion is horrible.
 

hehe i know it's distortion is horrible and it has moustache distortion

but i'm looking for something relatively cheap and light.. so i roughly know what i'm paying for... just that the difference between the right and left side of the frame is so pronounced it bugs me

LEFT:

8262723545_dfde7bb53c_o.jpg


RIGHT:

8262723373_9a990aa939_o.jpg
 

I do agree that the left looks horribly mushy compared to the right.

Is there a refund option? There must be a reason you're looking for something this wide and light. Going for the 85mm upgrade version abit pointless leh.. Eventually you'll also be looking at this lens again.
 

Hmmm..... dpesn't look good. I haven't had a misaligned lens for about 10 years and from what I understand, its a fix which needs precision. Hope you can either get it fixed or exchange for something else. Usually, reasonable 2nd hand dealers will let you exchange.
 

I do agree that the left looks horribly mushy compared to the right.

Is there a refund option? There must be a reason you're looking for something this wide and light. Going for the 85mm upgrade version abit pointless leh.. Eventually you'll also be looking at this lens again.

i do use my current 85 a fair bit and i could use the upgrade but yes eventually i'll be looking for another copy of the 20mm.

and yes TCW is letting me exchange which is why a new grey 85 1.8 G is on the cards for me (if after servicing this copy is still bad, and if they don't have another copy in shop at the moment)

either way i'll gain lah.

my budget FX set up i'm working towards:

D600, 20mm 2.8 D, 50 1.8 G, 85 1.8 G, 180 2.8D

presently:

D300, 20mm 2.8D (this chui copy), 35 1.8 (to be sold when I go FX), 85 1.8D, 180 2.8D

almost there!
 

i do use my current 85 a fair bit and i could use the upgrade but yes eventually i'll be looking for another copy of the 20mm.

and yes TCW is letting me exchange which is why a new grey 85 1.8 G is on the cards for me (if after servicing this copy is still bad, and if they don't have another copy in shop at the moment)

either way i'll gain lah.

my budget FX set up i'm working towards:

D600, 20mm 2.8 D, 50 1.8 G, 85 1.8 G, 180 2.8D

presently:

D300, 20mm 2.8D (this chui copy), 35 1.8 (to be sold when I go FX), 85 1.8D, 180 2.8D

almost there!

Or if not see if they have the 35mm f/2D or not lor, since you seem to be missing a 35mm, but that's if you need it. The 20mm f/2.8D and 35mm f/2D should be the same price range bah.
 

Or if not see if they have the 35mm f/2D or not lor, since you seem to be missing a 35mm, but that's if you need it. The 20mm f/2.8D and 35mm f/2D should be the same price range bah.

about $200 difference I believe, presently not looking for the 35 f2 too much CA haha
 

anybody wants to share full res photos from their good copy of the 20mm to show what it is capable of? :bsmilie:

Ben if u have a manual copy of 20mm can share here too hurhur
 

anybody wants to share full res photos from their good copy of the 20mm to show what it is capable of? :bsmilie:

Ben if u have a manual copy of 20mm can share here too hurhur
Did you buy a new copy made in Thailand or is it an older used one?
 

Last edited:
anybody wants to share full res photos from their good copy of the 20mm to show what it is capable of? :bsmilie:

Ben if u have a manual copy of 20mm can share here too hurhur

lhttp://www.photozone.de/nikon_ff/617-nikkorafd2028ff?start=2

Can see from there :)
 

Did you buy a new copy made in Thailand or is it an older used one?

a 2nd hand copy i hastily picked up.. guess i shouldn't be too paiseh about a quick pixel peep on laptop next time
 

a 2nd hand copy i hastily picked up.. guess i shouldn't be too paiseh about a quick pixel peep on laptop next time

Usually decent 2nd hand shops are nice and let you play with the lens very long ;)
 

Why not getting a new one?

feel that it's not worth paying $800+ for first hand when u can possibly find a good 2nd hand copy for about $650.
 

Status
Not open for further replies.