EF 24-105mm f/4L Soft and Hazy

[wilmark]

I have the above lens that is very soft and hazy - but i cannot see any dust or mold. I think i want to try to tear it down and see if i can do anything with it.  Like this guy is doing here: 

https://www.youtube.com/watch?v=bdShwMk-LDc

But he says that the "Axis Test" showed poor results early in the video. I gather that some of the elements are misaligned causing the blurriness. I'd like to confirm that it is indeed an axis problem. Any idea what exactly is an axis test? What charts are used? Is it the same as a lens calibration test?

[Anonymous]

I see a slight improvement without the filter. Is the front and rear element of the lens perfectly clean with no smudges or fingerprints?

[wilmark]

Yes its all clean. The 70-200 is way cleaner and lacks any haze, all the 24-105's have this haze on it. The latter is wide open at 4, while the former is 2.8. 

[Anonymous]

With clean front and rear lens elements and no filter installed, there would appear to be some problem with the lens. I would recommend getting it serviced.

[Waddizzle]

Do not take the lens apart.  You can disassemble it with two hands, but you’re gonna need about eight hands to put it back together.

What camera are you using that produces hazy results?  Do you get hazy images with only this one lens?

[wilmark]

Thanks for the advice, I will need to watch more videos and make sure i can document the process. and know how to get it back. But its a skill i'd like to be able to do as i find that Labor cost on servicing is a real killer. 

See my post above to 5 DIV for the description and the lens/camera issue.

[Waddizzle]

If you sent it to Canon for a repair and it came back with a performance issue, then I have to ask whether or not have you tried to contact Canon.  Any repair should be covered under a repair warranty.  

I think you need to talk to Canon Support, not social media.

[wilmark]

I explained why this became a problem in one of my other posts here. Im not blaming canon, I realized the problem with the repair too long after the repair. My question/post is fairly specific - its about testing a lens to see if there is an Axis or alignment problem. Sending it back to canon will mean at least 400$ + shipping and Duties when the camera enters back my country and i still might not fix it, and i dont consider this feasible at this point. Which is why i contemplated this. 

[kvbarkley]

I am going to guess that it is the "newspaper test" as shown on the third page of this page:

https://bobatkins.com/photography/technical/testing_lenses.html

[wilmark]

Thanks - ill try this. 

[ebiggs1]

My advice as my associates have indicated don't take the lens apart. There is nothing you can do at home to repair anything related to alignment issues or decentered. Now if you just want to run the percentages or chances keep these in mind. It is highly unlikely that Canon returned a faulty lens. Not impossible but surely way improbable. Secondly, it is very highly likely the UV filter is causing the issues. Discard it today. Keep the hood always. Lastly and I know, most untasteful, is the fact 90% of all OOF and/or any focus issue is user caused and not do to gear.

Someone mentioned, "Is the front and rear element of the lens perfectly clean with no smudges or fingerprints?"

This, too , is not the cause unless it is really smudged to be obliviously noticeable. These parts of the lens are OOF to the camera sensor and generally will not effect the picture. Since light is everywhere and not simple straight lines it will pass such imperfections. I have seen font elements that were cracked that did not show up in the photo.

Try the test KVB suggest