So You Want To Know The Repair Cost?

Well the lens is certainly sharp enough, but I've never seen artifacts like that before. Hopefully someone has, and can give an explanation.

I get nervous buying used, but at the same time, I find it easier to 'trust' someone from this forum than to buy off of ebay. Most of the people in here are photographers and (to some extent or other) know how to take care of their equipment.

I've bought my 70-200 f4 L (and the sharpness wide open is shocking), my gf's XT, and a broken F-1 on here, and all of them have been better than I expected. Heck, the F-1 came with the original box, and I didn't know it was going to.

braduardo wrote in post #2213067
I get nervous buying used, but at the same time, I find it easier to 'trust' someone from this forum than to buy off of ebay. Most of the people in here are photographers and (to some extent or other) know how to take care of their equipment.

I've bought my 70-200 f4 L (and the sharpness wide open is shocking), my gf's XT, and a broken F-1 on here, and all of them have been better than I expected. Heck, the F-1 came with the original box, and I didn't know it was going to.

I agree.

I think you just need to seek out the right deals and search for sharp copies. A large portion of the time people are selling for legitamate reasons, i.e. they have no option (emergency), or that they have upgraded to something better (i.e. selling a 70-200 F4L because the person has upgraded to a f2.8L IS.) The guy I bought my 70-200 F4L and 85 1.8 was very nice, and he even showed me magazine cover photos that were published done with the 70-200 F4L.

I think that you just need to be smart when buying, ask for sample photos, have them send you photos that prove it's sharpness, etc.

canonloader wrote in post #2212973
I tried it with IS on and off, and no tripod, but a solid brace.

But, I think I found the problem. Maybe the same problem I've had from the beginning, at least some of it. I found another post about this by searching Google. It turned out to be the filter they were using, but their images showed the same exact lines at the same angle.

I ran out of daylight so can't test it til tomorrow though.

Didn't see your possible filter explanation when I posted. I hope that's the problem.
Must be a major relief for you!

It is a relief. I just got done testing again, inside, under bad lighting. No filter, put the hood on, manual focused, on the tripod and using the timer so I didn't move anything and then shot at ISO 100. I did this same test before I sent it off to Canon and the pictures are way sharper than they were before. It's not the lens.

Final test though, will be in daylight, shooting from the same spot, to the same spot, without the filter, and see what happens.

Please keep us posted.

I had to send my camera in to Canon today...33 days old only....

I thought it was my LENS that was backfocussing, but I got it exchanged and the new lens was back focussing as well. I then took the kit lens out (normally keep my 50mm mounted, never ever really used the kit lens) and guess what...kit lens back focussed as well

I then looked at some pictures I took with my 50mm 1.8 when I had it and noticed a bit of BF in those pics as well....

Costed me 65$ to ship <200miles because I insured it for 1000$ I shouldnt have bothered with insurance.

also noticed in my test shots that my kit lens was soft on the right side of the picture and not the left(even when on a tripod)....so I sent that in too.

seems like I got a Friday built XTi =(

hoping to hear back from canon next week and maybe the sensor will come back fresh and clean as well.

overall...I am pretty damn upset....

canonloader wrote in post #2213609
It is a relief. I just got done testing again, inside, under bad lighting. No filter, put the hood on, manual focused, on the tripod and using the timer so I didn't move anything and then shot at ISO 100. I did this same test before I sent it off to Canon and the pictures are way sharper than they were before. It's not the lens.

Final test though, will be in daylight, shooting from the same spot, to the same spot, without the filter, and see what happens.

I call that bad effect "scratchy bokeh".
Here is my example (with filter)

That's it Dave. Thanks for posting that. But, after looking at my filter again, it is NOT a UV, it turns out to be an Omega Skylight 1B. So apparently, it's any cheap filter, not just a UV filter. What a simple to fix yet hard to find the cause of problem. This one needs to go into the manual under troubleshooting.

canonloader wrote in post #2214817
That's it Dave. Thanks for posting that. But, after looking at my filter again, it is NOT a UV, it turns out to be an Omega Skylight 1B. So apparently, it's any cheap filter, not just a UV filter. What a simple to fix yet hard to find the cause of problem. This one needs to go into the manual under troubleshooting.

Heh. Don't sweat it with filters, just use your hood. It's a controversial debate, but I'm too cheap to go buying filters for all my lenses, plus, sometimes a little scratch won't even affect IQ, and at the worst you can send it in to Canon and have them repair the front element or whatever.

Well, this should close out this problem. I took the filter off, shot with the IS on, hand held and got these this morning. I'm exstatic with the Canon service on this lens.

The light was terrible, dark gray, no flash used, Aperture Priority. The rest of the EXIF is intact. Not only these two, but a couple hundred more came out very well also. Absolutely no PP other than resize for the board in CS2. This is how they came from the camera.

Byte size: ZERO | Content warning: NOT AN IMAGE

Byte size: ZERO | Content warning: NOT AN IMAGE

Great ending to your story. Congratulations!

Aside from the obvious IQ degradation when using a filter, I am convinced that they also have something to do with the focusing gizmo. Not sure how that works, but these are the sharpest images I have gotten from any of my lenses. All of which have some sort of protection filter on them all the time, like a UV or Skylight filter. I guess I have to rethink that habit.

canonloader wrote in post #2216371
Aside from the obvious IQ degradation when using a filter, I am convinced that they also have something to do with the focusing gizmo. Not sure how that works, but these are the sharpest images I have gotten from any of my lenses. All of which have some sort of protection filter on them all the time, like a UV or Skylight filter. I guess I have to rethink that habit.

Well, you'll find plenty of reading material, both pro and con filters on this forum. Seems like a new thread rears it's ugly head a least once a week.
Some discourage all filter use and many, if not most, conclude that cheaper filters degrade IQ and cause flare, while good filters like B+W and Heliopan MRCs have no adverse effect.
I personally am in the second group, using only B+W MRC filters for protection on all my lenses.

I've always kept filters on my lenses. It keeps them clean and protects them. I can replace a scratched filter a lot easier than a lens, and I'd rather clean a filter than the coating on an expensive lens.

But, at least with this 100-400L with IS, I will do without. I use a UV on the Sigma 105, and there seems to be no problems.