Nikon 20mm 1.8G not sharp at infinity

Hc

My like new used Nikon 20mm 1.8G arrived to day and looked good. At close and middle distances the lens is tack sharp, but at long distances and infinty it is rather dull. Needless to say l am disapointed. l am using the lens on a D610. Any sugestions on what is wrong with the lens.

What aperture?

What method of focus?

I've got the 20/1.8G - so, okay, it's not a Zeiss Milvus 25/1.4 or the insane Sigma 40/1.4 Art, but it is most definitely sharp at infinity, once you've stopped it down a bit. So something seems off....

-m

anotherMike said:

What aperture?

What method of focus?

I've got the 20/1.8G - so, okay, it's not a Zeiss Milvus 25/1.4 or the insane Sigma 40/1.4 Art, but it is most definitely sharp at infinity, once you've stopped it down a bit. So something seems off....

-m

Click to expand...

I would expect a lens like this to be quite sharp over most of the frame wide open, and extremely sharp stopped down a bit.

If I had to guess I'd suspect an autofocus miss, rather than an optical defect. Does it get sharper if you use Live View manual focus (or Live View contrast AF)?

1) Wide angles are very difficult optical designs and very few are what I'd grade as "excellent" - maybe a handful if that. So if one is expecting a lot of across the frame sharpness wide open, one is expecting too much. Really very, very, very few lenses can do *that* wide open (really only the Sigma 40/1.4 Art honestly).

Stopped down, my own thoughts are that I'm only happy with the corners and edges with my 20/1.8G starting about F/7.1, but I might prefer F/8 or F/9, and many lenses aren't as good even at those apertures in the corners/edges (the 14-24 in particular is clearly beaten by the 20/1.8G even at F/9 in the corners/edges) This is sort of typical with a lot of wides on a very high resolution body. My Zeiss 25/1.4 can do it around F/5.6 on some subjects, but that's a 2 grand+ lens that weighs more than a pair of 20G's and ridiculously large as well.

2) I'd definitely agree that the OP should check their focus by using live view as the somewhat golden reference. If they are using AF-S and the lens needs fine tuning, then that might explain poor sharpness.

-m

OP using the word "dull" to describe the infinity results makes me wonder if atmospheric conditions might have affected his results too. Haze is common and can cause that effect.

Thanks for your replies. Lens will be sent back to the seller.

Andre Yew said:

OP using the word "dull" to describe the infinity results makes me wonder if atmospheric conditions might have affected his results too. Haze is common and can cause that effect.

Click to expand...

+1

The lens should be as sharp as is the distant detail - focussed manually.

With haze combined with the size of distant objects reduced with a wide angle, AF does not necessarily work well.

Without a sample images there is no way of knowing if the lens had a fault - or if the OP did not know AF does not focus good on everything.

The OP will return the lens to its previous owner with full refund.

The end

Egil Stroemme said:

Hc

My like new used Nikon 20mm 1.8G arrived to day and looked good. At close and middle distances the lens is tack sharp, but at long distances and infinty it is rather dull. Needless to say l am disapointed. l am using the lens on a D610. Any sugestions on what is wrong with the lens.

Click to expand...

WIthout posting a full size picture no one can instruct you properly. Post up a full size jpg no editing and owners' of the lens like myself can help you. I'll bet the lens is good but let's see...I've shot with this lens a lot lately and I find it truly excellent. I see you are returning / returned it. My thoughts are it may be a good copy of the lens and you simply aren't aware of how it functions at infinity IQ wise.

Egil Stroemme said:

The OP will return the lens to its previous owner with full refund.

The end

Click to expand...

Hi, I would do some good testing before returning a lens. Many ways to test a lens. Live view versus viewfinder image shooting a good target. With no images included in this thread makes it impossible for us to give you some better comments.

Larry

Nice that you keep posting but the lens is going back to its previous owner.

primeshooter said:

Egil Stroemme said:

Hc

My like new used Nikon 20mm 1.8G arrived to day and looked good. At close and middle distances the lens is tack sharp, but at long distances and infinty it is rather dull. Needless to say l am disapointed. l am using the lens on a D610. Any sugestions on what is wrong with the lens.

Click to expand...

WIthout posting a full size picture no one can instruct you properly. Post up a full size jpg no editing and owners' of the lens like myself can help you. I'll bet the lens is good but let's see...I've shot with this lens a lot lately and I find it truly excellent. I see you are returning / returned it. My thoughts are it may be a good copy of the lens and you simply aren't aware of how it functions at infinity IQ wise.

Click to expand...

+1, need to know how to test a lens.

Larry

So many folks think if they just place the center mark right in the middle of the infinity symbol, all will be okay.

Live View at 100% zoom is so valuable.