p.3 #1 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
I had an issue with soft images out of my 100-400 Fuji lens earlier this year. Spent many hours fiddling with IS modes, etc. Took the UV filter off and bingo, problem solved. No more UV filters for me. The particular filter was a Hoya--probably 10 years old, but high-end at the time.
p.3 #3 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
JameelH wrote:
Interesting find about filters affecting the lens sharpness. It is worth finding out how much filters other than UV affect this - CPLs, ND etc.
Do a search. It has been discussed on this site, and elsewhere, many times.
p.3 #4 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
Follow up post:
Although the original issue was improved significantly by removing the filter, occasionally I was still experiencing the far left side of the frame go completely soft at 200mm, even when stopped down (entire far left side when shooting in landscape orientation).
The lens arrived at Canon CA for repair today, so I should hear back in a day or two – will report back the outcome.
p.3 #5 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
Don't be too surprised. I just sent back a RF24-240 that had a weak right side. I haven't had this since working with a Nikkor 70-300 that was decentered. It happens. But when you get a good one.....oh my what a huge difference it makes indeed. As for filters nearly 20 years ago I had a backpack full of L lenses with a original 1D and the filters, which were top Hoya and B+W's, never effected the IQ on iota. I even tested them for that specifically and indeed they had NO negative effect whatsoever. Now however.........I don't bother with filters. I don't go to saltwater exposed areas like oceans nor expose my lenses to excessive dirt. I have some lens pens in case the element got a bit dusty but that's not an issue I need a filter for.
p.3 #6 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
dcisive wrote:
Don't be too surprised. I just sent back a RF24-240 that had a weak right side. I haven't had this since working with a Nikkor 70-300 that was decentered. It happens. But when you get a good one.....oh my what a huge difference it makes indeed. As for filters nearly 20 years ago I had a backpack full of L lenses with a original 1D and the filters, which were top Hoya and B+W's, never effected the IQ on iota. I even tested them for that specifically and indeed they had NO negative effect whatsoever. Now however.........I don't bother with filters. I don't go to saltwater exposed areas like oceans nor expose my lenses to excessive dirt. I have some lens pens in case the element got a bit dusty but that's not an issue I need a filter for....Show more →
I never saw the filter issues until the R5 and until I started looking with versus without at long focal lengths. The B+W is not terrible, but the Zeiss T* or no filter at all was noticeably better at 1:1/2:1.
p.3 #7 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
Updated outcome – a lens group in the RF 70-200 f/2.8 is being replaced by Canon. Should have it back in a couple of days.
So during the process, I at least learning to not use filters if you want to best evaluate sharpness, but the filter was probably not the major issue here.
p.3 #8 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
So if you don't use UV filters your lens gets ruined in a thunderstorm in the rain, but if you do your image is sub par. Tough choice people. Got to say I have never noticed any significant difference + or - filters unless you are shooting against the light and get extra flare with a filter
p.3 #9 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
Robin Smith wrote:
So if you don't use UV filters your lens gets ruined in a thunderstorm in the rain, but if you do your image is sub par. Tough choice people. Got to say I have never noticed any significant difference + or - filters unless you are shooting against the light and get extra flare with a filter
You probably wouldn't notice any issues unless you've done a with/without comparison with a 45+mp camera on an extremely demanding/detailed subject and examined the results at high magnification.
But as much as I would love to run without protective filters, the wind/dust where I live (and rain during monsoon season) doesn't make it wise. And like I mentioned in the thread, the B+W with/without was better without, while Zeiss T* with/without was no difference – so I'm moving to Zeiss over time.
p.3 #10 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
What I've been doing for perhaps the last 20 years as soon as I got a new lens, or camera, placed it on a tripod at a reasonable distance from a wall, that had a properly aligned resolution test printed to at least if not larger than 13x19. I would situate the coverage of the lens to cover to the edge of print on the chart. I'd take multiple shots at base on up f stops to verify it's strengths and weaknesses. If I caught a lens that had weak corners or worse an entire side it went back. It probably happened at least 3 or 4 times over those years. The replacements were always perfect. I would have done something like this with your body but with the IBIS OFF to verify that had nothing to do with it. Just sayin........
p.3 #11 · Sharpness issues on RF 70-200 f/2.8 – far left side is blurred
dcisive wrote:
What I've been doing for perhaps the last 20 years as soon as I got a new lens, or camera, placed it on a tripod at a reasonable distance from a wall, that had a properly aligned resolution test printed to at least if not larger than 13x19. I would situate the coverage of the lens to cover to the edge of print on the chart. I'd take multiple shots at base on up f stops to verify it's strengths and weaknesses. If I caught a lens that had weak corners or worse an entire side it went back. It probably happened at least 3 or 4 times over those years. The replacements were always perfect. I would have done something like this with your body but with the IBIS OFF to verify that had nothing to do with it. Just sayin...........Show more →
While we are "just saying": This lens didn't fail when I first bought it, it failed after a few months. I test all my lenses, too, but at 1/2 mile to infinity range – a bit too far for brick wall navel-gazing. Close-distance corner sharpness is not something I care about. If I'm shooting close distance, I'm shooting wide open with a central subject.
I'll know more when I get the repair order back with the lens, but I'm guessing the lens group they're replacing is the IS group since the issue would vary in how bad it was, sometimes disappearing completely. Sharpness issues caused by IS inaccuracies may not show up in a tripod test, so maybe you should also test your IS lenses off a tripod.
–> Edit for context: Canon first tested the lens (I'm assuming at test chart distance and/or on a lens testing device) and told me it was within spec. They then asked for the R5 body in case that might show the issue, so I sent them the body. But I also told them it wasn't an issue that was easy to see at close distance – only at 200mm and infinity focus. So I'm not sure if they tried it at infinity and saw the issue or just decided to break down the lens on my insistence and found the issue. Point being, even Canon can test the lens and think it's within spec, but in real-life use other issues may show up, particularly where IS is involved.
