Albuqshutterbug Loc: Albuquerque NM

I received my Canon lens back from repair yesterday.
The autofocus assembly was replaced and it appears as if they either replaced my front lens or polished out the tiny scratches that were there. I did a few hand held shots of ol man Luna at full zoom.
ISO 100 f/11 1/125th IS on.
Not my favorite time of moon to shoot but it didn't do that poorly.

Full Moon

(Download)

SonnyE Loc: Communist California, USA

Nice!
I can tell the scratches are gone, too....

.... :roll:
:lol:

CraigFair Loc: Santa Maria, CA.

I love the Moon in all it's phases, nice shot Jim.
Craig

Albuqshutterbug Loc: Albuquerque NM

You can? rofl.
Thanks Sonny.

Albuqshutterbug Loc: Albuquerque NM

It's soooo frickin flat. I hate full moon shots but wanted to test the focus and stabilization.
I may have to micro adjust to make me happy.. What can I say..
Thanks Craig, Rant over.. lol

CraigFair Loc: Santa Maria, CA.

Do you have the Auto Focus Fine Tune capabilities in you camera???
I did mine at 600mm on my Tamron 150-600mm and I got a noticeable difference in sharpness.
Which reminds me I need to do all my other lenses. That will give me something to do this afternoon.
Craig

Albuqshutterbug Loc: Albuquerque NM

It's called autofocus micro adjust and I have it in both the 7D and the 5D Mark II. It allows you to correct for front or back focus on up to 20 different lenses and or lens combinations. IE 300mm with 2X extender.
I used my best guess tweaking on the Tamron and set it at +5. It is much sharper.
I need to find the sweet spot for this lens although I don't think it is very far off based on a few shots I shot during my break at work.

rocketride Loc: Upstate NY

rocketride Loc: Upstate NY

I'm pretty sure you got a replacement front lens. First, since the front element or group is so vulnerable, the manufacturers make extras. (Actually, they make extras of all of the elements/groups, but more of the front and rear ones because these are the ones in best position to get damaged, being on the exterior of the lens.)

If they had just locally 'repolished' the scratches, there would be patches of uncoated glass on the surface, and an uneven 'figure' on the optical surface.

So, they'd have to repolish the entire surface instead, and test it to make sure they hadn't added any unwanted deviation from the designed curve. Which is merely a pain in the butt if it is a spherical surface and a complete b---h to do on an asphere. If they had to grind and polish more than a very, very, very thin layer off, it would alter the optical correction of the lens element, and therefore the correction of the entire lens assembly. In which case, they may or may not be able to compensate for this by adjusting spacings between lenses and groups.

Also, to get 'like new' appearance and performance, they would have to have applied a new multicoating.

Except possibly for a large element made of an exotic glass, or for a very expensive optical system with no replacement part available, this would generally be more trouble and hugely more expense than it's worth. (It would probably cost much more than just replacing the entire lens.)

Albuqshutterbug Loc: Albuquerque NM

I am pretty sure they replaced the lens and the front hood ring. Both look like new.

Here is what I got with my micro adjust tests on the 5D Mark 2

Focus point was the large Kobalt circle on the side but the end improved as well at +3

Unadjusted

(Download)

-3

(Download)

+3

(Download)

CraigFair Loc: Santa Maria, CA.

Sweet job Jim was the difference about 5 on the scale???
Craig
PS: Oh, I see it now a +3.