KelvinCJ From United Kingdom, joined Mar 2012, 34 posts, RR: 0 Posted (3 years 4 weeks 1 day 4 hours ago) and read 8034 times:
First off, I am sorry for posting another topic on the same subject - and hence for wasting bandwidth etc.
I wanted to post in my old topic but saw that it was archived and hence unavailable for me to do so.
I just wanted to update those of you that very kindly helped and advised me regarding my lens and the possible problem(s) I was having.
I received it back today and am pleased to say that it is a lot better in regards to quality and sharpness. It seems like it was £154 well spent.
Perhaps the most singular evidence I have of the 'improvement' arises from the uv filter versus no uv filter aspect.
Before I sent the lens off for repair, I could see no difference, at all, in terms of image quality or sharpness when using a uv filter or not.
Now, the difference is clear. The quality and sharpness are greatly improved when not using a uv filter. (Even at the 100mm end).
Unfortunately I have not taken it spotting yet but am pleased with my initial findings.
I just wanted to let you all know of my outcome, in case any one else finds themselves in a similar predicament.
kelvincj From United Kingdom, joined Mar 2012, 34 posts, RR: 0
Reply 1, posted (3 years 4 weeks 1 day 1 hour ago) and read 7999 times:
I managed to upload two test examples - with a uv filter and without a uv filter. Before I sent the lens off for repair, all my examples appeared like the uv filter crop example - it seemed to be missing that sharpness kick.
UV Filter Crop
No UV Filter
No UV Filter Crop
I am pleased with the service centre for fixing my apparent issue, and hope that if any one else finds themselves in a similar situation they either return the lens straight away to get a replacement - or, if out of return time / warranty, consider a repair at the service centre.
dlednicer From United States of America, joined May 2005, 555 posts, RR: 6
Reply 2, posted (3 years 4 weeks 1 day ago) and read 7976 times:
AIRLINERS.NET CREW DATABASE EDITOR
I was a lurker on the last thread, but it gave me a good heads up. I sent both of my lenses in for overhaul and it was well worth it. In particular, the overhaul got all of the dust out of my Canon EF-S 17-85mm f/4-5.6 and cleaned up a sharpness drift in my Canon EF 100-400mm f/4.5-5.6L IS USM. Looking at images, I've been able to identify that the drift in sharpness happened in a fairly short time period this spring, but I have no idea what caused it.
dazbo5 From United Kingdom, joined Mar 2005, 2956 posts, RR: 2
Reply 3, posted (3 years 4 weeks 1 day ago) and read 7967 times:
Quoting KelvinCJ (Thread starter): Perhaps the most singular evidence I have of the 'improvement' arises from the uv filter versus no uv filter aspect.
Which tells it's own story, don't use a UV filter as it's not needed! UV filters make no difference with digital sensors, only film as digital sensors aren't sensitive to UV. while I see the argument of having a filter on to protect the end element, I've never had the need as the lens hood offers sufficient protection as long as you're careful with your equipment. After all, why pay over £1,000 for a high quality lens than attach a relatively cheap piece of glass on the end? As you've seen, filters effect image quality so personally, I'd leave it in the box.
Glad to hear you're pleased with the results now though.
Equipment: 2x Canon EOS 50D; Sigma 10-20 EX DC HSM, 50-500 EX APO DG, Canon 24-105 f/4 L, Speedlite 430EX
stevemchey From United States of America, joined Feb 2009, 370 posts, RR: 0
Reply 4, posted (3 years 4 weeks 1 day ago) and read 7967 times:
Just out of curiosity, which filter (brand and price) did you use?
I know there is a lot of debate about the usefulness of a UV filter (or the lack thereof). I am often using a filter for protection (especially during wedding shoots, shoots along the beach and sporting events) and can only conclude: If you decide to use a filter, you need to go with the high end ones. A $20 filter only makes your images worse. A $100 UV filter might not improve your images, but at least it doesn't do (much) harm.
So, in answer to your question Stefan: Zeikos ZE-UV77 and around £10 or $15 - exactly as you say - onlymakes images worse. Interestingly enough - after I saw the difference I went straight online and decided to order a Hoya HD 77mm UV Filter - not necessarily for the 'quality' but with the idea of comparing the two - to see just what a difference the 'quality' and 'price' actually makes first hand.
Quoting dazbo5 (Reply 3): why pay over £1,000 for a high quality lens than attach a relatively cheap piece of glass on the end?
A very good point - and I must agree with you there. I think paranoia is the major component of my desire for a filter however. I would much rather clean the surface of a uv filter to remove dust etc. than the surface of the lens - incase of a scratch or mark.
Thank you for your replies, and I am glad you found it a worth while experience David.
ckw From UK - England, joined Aug 2010, 810 posts, RR: 15
Reply 6, posted (3 years 4 weeks 20 hours ago) and read 7930 times:
I'm not a fan of filters, but will use one in adverse conditions - note that Canon states that its L lenses require a filter to acheive full weather proofing. Of course a cheap filter is not a good idea - if you need one, expect to pay big money for a quality multi coated filter from, for example B+W
comairguycvg From United States of America, joined Jan 2006, 346 posts, RR: 1
Reply 7, posted (3 years 3 weeks 6 days 17 hours ago) and read 7804 times:
I had a filter on my 100-400 L lens and removed it. Images were soft looking because with a filter, it's just another layer of glass the lens has to look through. More layers = more softness. I think mine was a Promaster.