Lens cleaning/repair service

[RacingSnake]

Hi guys,
I've been a little 'unsure' about the sharpness of my pictures recently.
I've got a 100-400L, and compared to when I bought it a year ago it just doesn't seem to have that razor sharp finish it used to.
it seems to just go a little soft at 400mm.

I don't have any notable dust spots on the images, but there are a couple of tiny specs on the inside of the lens.
I've never had it cleaned, so the question I am asking is, is it worth sending it for a 'routine' clean & repair, and am I likely to see any improvement?

I appreciate this is a bit of a 'it depends' question, but there are seemingly no other issues with the lens, it operates and focusses fine, just doesn't seem to quite get the sharp end in. :thumbsdown:

(Have already got a quote from Elstree re: their clean & service)

 

[boyfalldown]

depends

a couple of dust spots inside the lens shouldn't cause you issues but its possible calibration has wondered out slightly.

 

[RacingSnake]

well, it hasn't been abused, but it has (once) fallen off our table onto the floor , my camera took the brunt of it on that occassion, but everything functioned fine.

It's probably really pertinent to the original post but since everything appeared fine (apart from a scratch to my camera ) I thought nothing of it?!

 

[cuthbert]

but it has (once) fallen off our table onto the floor , my camera took the brunt of it on that occassion, but everything functioned fine.

almost certainly a calibration is all that's needed. i've read in many places that the odd sharp knock and shift some of the elements slightly, especially in some lens designs.

i think you can ignore the dust, although some people have noticed that some copies of this lens have a fault where there appears to be some black bits of paper inside the lens - somebody else might be able shed some light on this, i think it was a defect with the friction ring, but can't recall.

but in short, i think a calibration is all you need here.

 

[RacingSnake]

Okay thanks, this should be covered under canons repair and service right? Of course i'll ask when i go there on monday, but just checking

 

[RacingSnake]

Seriously impresed with the Canon repair centre in Elstree.
I went up there yesterday in my lunch hour (2 hours ), aside from taking 1hr 20 to travel the 14 miles from the office I found the place okay and handed it over with a note saying I must have it back by 25th feb at the absolutely latest.
Got a text and email this morning that it was all done!

I phoned them up, paid by card and they're going to ship it back to me UPS for tomorrow (as I didn't fancy driving up there again), together with a report of the work completed.
looking forward to getting it back (probably won't notice a difference lol), but certainly so far, the process has been very slick.