Snowbro Posted January 26, 2019 Share Posted January 26, 2019 I just got a new Canon 70-200 2.8 IS II, I needed a second copy. I had to shoot a mountain range during sunrise today at around f8, then later discover that there was dust in the lens. I looked at the lens face and didn't see anything, then I shined a light in and saw a few LARGE pieces of dust inside towards the front. I have never seen this in any of my Canon lenses, this lens is brand new lol. It also was professionally calibrated at the wide & telephoto for focus, yet it is very soft at infinity focus. The mountain range was soft on this lens in 4k/photos, softer at 70mm by far, even when shooting test portraits. I also checked my sensor and it was completely clean. I doubt i'll see the dust when shooting more wide open, but I guess I will have to deal with returning this lens.. Sucks. My other copy has no dust and is extremely sharp at all focal ranges and focusing distances. Anyone had anything similar before? Guess I got lucky with the first copy. Quote Link to comment Share on other sites More sharing options...
Shirozina Posted January 26, 2019 Share Posted January 26, 2019 A few dust fibers won't degrade the image but I'd be more concerned at the softness at infinity which indicates it wasn't calibrated properly - yes return it! Quote Link to comment Share on other sites More sharing options...
Snowbro Posted January 27, 2019 Author Share Posted January 27, 2019 I calibrated it with a pro tool after seeing it was soft, helped a little, but not enough. The dust pieces are really big, they actually leave huge spots on my video when shooting over f5, which I need to do sometimes. Similar look to when someone has a bunch of gunk on their sensor (verified mine is clean, it's the lens). It seems a like a refurbished lens from adorama, but I paid for new. Just a little interesting lol, I have bought a few pro lenses from them last year and had no issue. Sensor clean, lens face & back were also clean.. (Harder to see with compression uploaded here, but it's bad) Quote Link to comment Share on other sites More sharing options...
Shirozina Posted January 27, 2019 Share Posted January 27, 2019 Those spots are sensor dust - a hair in the lens won't produce round shapes like that. How was it 'professionally calibrated'? - was this just the AF or did a tech adjust the lens elements? What camera are you using it on? Quote Link to comment Share on other sites More sharing options...
webrunner5 Posted January 27, 2019 Share Posted January 27, 2019 Yeah does look like oil spots. I had the same crap on my A7s. I Had to send it in to get cleaned. I could Never get the sensor cleaned after god knows how many tries with different reasonably expensive products. I just about wore the coatings off my lenses before I figured it was the sensor. Snowbro 1 Quote Link to comment Share on other sites More sharing options...
Shirozina Posted January 27, 2019 Share Posted January 27, 2019 Oil spots? looks like out of focus specs of dust as per normal sensor marks. Never had any problems using a gel stick on my Sony cameras but I guess dust may be able to get between the filter and sensor? Quote Link to comment Share on other sites More sharing options...
webrunner5 Posted January 27, 2019 Share Posted January 27, 2019 8 minutes ago, Shirozina said: Never had any problems using a gel stick on my Sony cameras but I guess dust may be able to get between the filter and sensor? Dust you can blow off with a Jet Blower or the like. That is a more involved problem than dust bunnies. Quote Link to comment Share on other sites More sharing options...
Shirozina Posted January 27, 2019 Share Posted January 27, 2019 28 minutes ago, webrunner5 said: Dust you can blow off with a Jet Blower or the like. That is a more involved problem than dust bunnies. Depends what the 'dust' is. It can be sticky and bond to the glass and no amount of air will shift it hence why a gel is my go-to tool. Never had a problem with dust between sensor and stack which I assume is a sealed unit. The OP's problem is typical of specs of foreign matter on the sensor cover glass given it's round shape. Dust in a lens - never seen this project it's shape on an image except on a very wide lens where dirt on the front element combined with enough DOF can show but the OP is using a long lens so again it all points to dirt on the sensor cover glass. webrunner5 1 Quote Link to comment Share on other sites More sharing options...
Snowbro Posted January 28, 2019 Author Share Posted January 28, 2019 I have been busy, so I dont get on here much now. I tested with my other copy at f/10 in a similar situation & do not see any spots. I also tested with my 85 and saw nothing. All 3 lenses were cleaned & sensor checked as I mentioned earlier. I see big pieces of dust in the lens, not the typical small little flakes telephoto lenses get sometimes from breathing. Maybe it isnt dust, but pieces of something else. Quote Link to comment Share on other sites More sharing options...
Snowbro Posted January 28, 2019 Author Share Posted January 28, 2019 Double checked sensor (different lens) and there were only two little pieces at the bottom area (f/16). Img I had attached before, was of the top corner. Quote Link to comment Share on other sites More sharing options...
Snowbro Posted January 28, 2019 Author Share Posted January 28, 2019 18 hours ago, webrunner5 said: Yeah does look like oil spots. I had the same crap on my A7s. I Had to send it in to get cleaned. I could Never get the sensor cleaned after god knows how many tries with different reasonably expensive products. I just about wore the coatings off my lenses before I figured it was the sensor. 1D bodies have been known for throwing oil around. I do shoot a lot at 14 fps stills or whatever it is; I shoot dirt biking/snowmobiling etc. sometimes. Having just two little spots after a year of use isn't terrible imo. Quote Link to comment Share on other sites More sharing options...
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