p.2 #1 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
rscheffler wrote:
While digging through the Lens Rentals blog earlier today, I read their UV/clear filter test from a few years ago. The B+W filters seemed to pass the optical portion of the test, though they only looked at central performance.
That said, one less layer of glass is one less variable.
On one hand, this is good news since it's an easy fix, if it indeed was the cause of the softness problem. On the other, it still leaves the cause of lockups unexplained.
Yes, going to keep an eye on the lockups. I mused over at Canon Rumors that I may be causing a lockup by powering on the camera while swinging it up to my eye and then powering it off while swinging it back down. Sometimes on the way to my eye while it's powering up, I'm already zooming because I know I want 200mm. So I might be causing the IBIS mechanism and/or IS lens group to get knocked around on occasion. Going to try turning on and waiting for power up to do anything same with power-off.
Always had good luck with B+W filters never a bad one until now. Even though the filter looks clean, that's going to be my first thing is to clean it front and back and try again then try another 77mm B+W if that's no better.
p.2 #2 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
I just had a filter mess me up too. A Tiffen, lower quality brand for sure. Made my whole frame soft on a 100-400 II. I thought it was an afma problem, but after testing, that filter was just adding tons of softness. I just stick with the lens hood now for protection.
p.2 #3 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
Two miles away puts a lot of air between you and the subject, and any turbulence in the air will create blur.
If you are testing a lens for sharpness, don't test on such distant subjects.
Also, obviously, don't have a filter on a lens you are testing. (Generally, if you are super concerned about absolute best sharpness, don't use UV filters.)
Dan
highdesertmesa wrote:
UPDATE:
Today's test: water storage tanks about two miles away
70-200 wide open and stopped down to about f5
Same tanks placed in bottom left and right corners by moving the frame for each shot (to rule out atmospheric effects, distance, and/or subject detail issues)
RESULTS:
When shot at f5, both corners are sharp regardless of which corner I focused on
When shot at f2.8, only the corner focused on was perfectly sharp.
The only conclusion I can come to is IBIS may not be able to perfectly align the sensor for infinity focus, so when shot wide open, IBIS will prioritize the alignment of the focused-on side of the frame over the other one.
Strange behavior, but I guess this is the compromise I have to live with for shooting with a sensor that moves. Moving forward when I need to shoot a landscape at f/2.8 or wider, I will try focusing along the bottom middle and see if that more evenly aligns the sensor....Show more →
p.2 #4 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
gdanmitchell wrote:
Two miles away puts a lot of air between you and the subject, and any turbulence in the air will create blur.
If you are testing a lens for sharpness, don't test on such distant subjects.
Also, obviously, don't have a filter on a lens you are testing. (Generally, if you are super concerned about absolute best sharpness, don't use UV filters.)
Dan
Testing 200mm for infinity sharpness doesnt give me much choice. If I focus closer than infinity, then its almost impossible to find a hill/ridge parallel to the sensor plane. At least here if I shoot early morning or right at sunset, the air is pretty stable: 5,500 elevation, low humidity, clear air.
Never had a B+W clear filter give soft results used them on all sorts of lenses with the 5DsR and GFX and now R5. Hopefully this bad filter is the outlier, but I agree I shouldnt have a filter on when testing sharpness. Im so used to having them on my lenses, I forget they are there!
p.2 #5 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
highdesertmesa wrote:
Did some more testing with IBIS/IS off this afternoon. Same softness/smearing on the left side. Thought I might try something super-obvious removing the B+W clear filter.
Left side is now perfectly sharp just like the right side.
Filter looks immaculately clean, so maybe it could be a manufacturing defect in the glass itself, or maybe having that extra piece of glass that light passes through is occasionally screwing with the IBIS focus calculation. I have a new 77mm B+W clear I'm not using will test that tomorrow. Or hell, I may just remove all my filters and never look back.
Did you rotate the filter and find the image defect to move with the orientation?
p.2 #6 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
EB-1 wrote:
Did you rotate the filter and find the image defect to move with the orientation?
EBH
Only with and without so far. I have the new filter on right now, so I'll test that first. If the new one looks good, then next up would be cleaning the old filter and rechecking. If after cleaning the old one still looks bad on the left, I can rotate it and recheck.
Only other thing I did differently with the filterless test shots was I had the tripod mount removed (had been thinking about sending it in for repair, so I removed it for shipping to Canon). I keep the tripod foot over to the left side, and had it tightened down super tight. Seriously doubt that could have been affecting anything inside, but who knows.
p.2 #9 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
If you are testing a camera for suspected sensor misalignment (or a faulty filter) why on earth take shots like these, either of the faults do not need to be tested at infinty focus especially on indistinct landscape shots which are likely to be affected by atmospheric distortion. Close up shots with the whole of the subject in the same plane would show the problem much better.
p.2 #10 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
Clicky94 wrote:
If you are testing a camera for suspected sensor misalignment (or a faulty filter) why on earth take shots like these, either of the faults do not need to be tested at infinty focus especially on indistinct landscape shots which are likely to be affected by atmospheric distortion. Close up shots with the whole of the subject in the same plane would show the problem much better.
That level of close up testing is outside of my wheelhouse. Doesnt it require some sort of lab setup to ensure the camera is parallel to the target?
I seem to have stumbled onto the culprit (dirty or bad filter) even if by less than perfect means.
p.2 #12 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
You are halfway there with your changed thread title. However, since the R5 itself had nothing to do with the problem at all, I urge you to remove the reference to it completely from the post.
Your post is really ONLY about the effect of filters on image sharpness and the point applies to all Canon cameras and to cameras from essentially any brand.
It is good that you recognized that there is nothing about lockups or sensor issues in your situation. It is equally true that there is nothing about the Canon R5 in the situation either.
(Leaving the title as is, suggests that there is something about the R5 and filters. There's no indication that this is the case.)
p.2 #13 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
Shots this morning with the new B+W filter show good sharpness in both corners, so this copy of the filter is better (or cleaner) than the last. However, I compared with/without the new filter, and the shots without are slightly sharper at 1:1.
I've always been a big supporter of using a high-quality protective filter, but no longer. I'll keep some of the clear filters in the bag for extreme weather, but they won't stay on my lenses any more.
p.2 #14 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
highdesertmesa wrote:
Testing 200mm for infinity sharpness doesnt give me much choice. If I focus closer than infinity, then its almost impossible to find a hill/ridge parallel to the sensor plane. At least here if I shoot early morning or right at sunset, the air is pretty stable: 5,500 elevation, low humidity, clear air.
Then focus on something else. One good target is the side of a tall building. If you are in a rural area, perhaps you can find a barn. If in an urban area, one good option is to photograph a multistory building from another multistory building. (Offering up "test results" that damn the performance of a lens when you know that you don't have decent test targets is a questionable approach.)
Aso, low humidity, elevation, "clear" air, and even low temperatures do not eliminate the distortions from disturbances in the atmosphere. I've observed them with using long lenses in such supposedly idea situations.
Finally, never test a lens with a filter attached unless your purpose is to test the filter itself in which case you would first test the lens alone to develop a performance baseline and then add the filter in order to check for variations. Filters, even good filters, can never have a beneficial effect on sharpness, and there are any number of situations in which they can degrade the overall optical performance. (And if you are are extremely critical about sharpness/resolution in your photography in general, do not leave UV/clear filters on your lenses add them only if and when they might be necessary.
p.2 #15 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
gdanmitchell wrote:
You are halfway there with your changed thread title. However, since the R5 itself had nothing to do with the problem at all, I urge you to remove the reference to it completely from the post.
Your post is really ONLY about the effect of filters on image sharpness and the point applies to all Canon cameras and to cameras from essentially any brand.
It is good that you recognized that there is nothing about lockups or sensor issues in your situation. It is equally true that there is nothing about the Canon R5 in the situation either.
(Leaving the title as is, suggests that there is something about the R5 and filters. There's no indication that this is the case.)
Your point is well taken, and I considered that when changing the title. But the reason I left it this way is I've seen a few posts about people specifically noticing issues having moved up to the higher-res R5. And this is the Canon forum and the post is not cross-posted to another forum.
Hmm, I guess I can change it to, "high-res camera" where I have "R5".
p.2 #16 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
highdesertmesa wrote:
Your point is well taken, and I considered that when changing the title. But the reason I left it this way is I've seen a few posts about people specifically noticing issues having moved up to the higher-res R5. And this is the Canon forum and the post is not cross-posted to another forum.
Hmm, I guess I can change it to, "high-res camera" where I have "R5".
How about: "Sharpness issues? Check your filter."
Anyone with an R5 or any other camera could have those concerns, and that title does not preclude R5 users from also finding your post.
p.2 #17 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
gdanmitchell wrote:
Then focus on something else. One good target is the side of a tall building. If you are in a rural area, perhaps you can find a barn. If in an urban area, one good option is to photograph a multistory building from another multistory building. (Offering up "test results" that damn the performance of a lens when you know that you don't have decent test targets is a questionable approach.)
Aso, low humidity, elevation, "clear" air, and even low temperatures do not eliminate the distortions from disturbances in the atmosphere. I've observed them with using long lenses in such supposedly idea situations.
Finally, never test a lens with a filter attached unless your purpose is to test the filter itself in which case you would first test the lens alone to develop a performance baseline and then add the filter in order to check for variations. Filters, even good filters, can never have a beneficial effect on sharpness, and there are any number of situations in which they can degrade the overall optical performance. (And if you are are extremely critical about sharpness/resolution in your photography in general, do not leave UV/clear filters on your lenses add them only if and when they might be necessary. ...Show more →
I've shot this same scene for over four years now, and ultimately I had to find out what the deviation was from my norm. Shooting a building or barn might work for a true "test", but not for testing for my situation. I'm not nor will ever be a formal lens reviewer just someone who posts their anecdotal experience.
Atmospheric effects are always there, sure, but for the most part at 200mm and with a FOV of about 1/4 mile across at my target, there shouldn't be too much deviation from one corner to the other but I ruled that out when I started moving the frame and putting the same man-made structure in each corner.
Hopefully no one is looking at what I'm doing here as "test results" in the sense of how knowledgeable reviewers test lenses I'm just doing tests for my specific situation to figure out what was wrong.
Your last point about filters is of course obvious now, is it not? Hopefully this thread can help others not chase ghosts and make false conclusions too quickly.
p.2 #18 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
gdanmitchell wrote:
How about: "Sharpness issues? Check your filter."
Anyone with an R5 or any other camera could have those concerns, and that title does not preclude R5 users from also finding your post.
Thread title updated to be generic and mention sharpness. "High-res" I feel is important to the title since I used this lens and filter combo on the R and R6 and the resolution was not high enough to show an issue.
p.2 #19 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
UPDATE:
Turns out my OCD just can't handle not having a clear filter on my RF 70-200 2.8. Every time I walk out the door in the high altitude desert here, I have a good chance of eating a gust of blowing dust/dirt/grit from out of the blue. And during the months of monsoon season, add mist/rain to the equation.
Got a Zeiss T* UV to see if the results are any better than the B+W Clear Nano filter that was reducing sharpness at infinity under 1:1/2:1 magnification. Will test it out tomorrow in the daylight.
p.2 #20 · Sharpness issues on RF 70-200 f/2.8 far left side is blurred
Tested this morning. Zero detectable IQ loss using the Zeiss T* versus no filter @ infinity and high magnification review. No more B+W filters for me at 45+ mp.
