Canon RF 24-105/4 dust inside. How to clean ?

Feb 10, 2021
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Hi.

After 2 years of using I clearly see more dust in my RF 24-105/4.
Its not 1 or 2 specks of dust but 4-5 and 1 quite big. When I shooting on f16 i can see 2-3 transparent disks on image from this lens. On F8 they disappeared.

Question is: If I want clean this lens by removing front element and blow out dust from it, can I do it like on old 24-105 (i see many video on youtube how it can be disassembled) or new RF lens made in some different way ???

Will be appreciated for any of advices,
Thanks
 

Joules

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Jul 16, 2017
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I highly doubt that you can see the spots of dust f/16. Most likely, what you are seeing is dust on your sensor, not in the lens. Check with another lens, stopped down against a uniform background (e.g. Sky) to confirm the disks remain in the same position.

Dust in the lens will render as haze, not actual circles in your image. Quick reminder how an entire fly looks like:


To clean your sensor, you'll find plenty of guidance online. I just drop my bodies off at the camera store on my way to work to let it be cleaned.
 
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Feb 10, 2021
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Thank you for answers.
Yes, I cleaned my sensor and I've tested with another lens. Same things that I've mentioned before - spots generated by lens on 24mm.

Now I'm trying to show a spots on photos.
Spots visible very well on 24mm f22. (horizontal and vertical shots)
But when I zoom in to 35-37mm - they not showing. Same thing on f8.
Hope I've illustrated problem well...
 

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YuengLinger

EOS R6
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Dec 20, 2012
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Do you shoot at the beach or other very sandy areas? Do you ever feel a slight grinding or crunching when you zoom?

Can you see the dust in the lens with your own eyes? Maybe using a flashlight?

What do you imagine you could do to get it out yourself? Do you have easy access to Canon service?
 
Feb 10, 2021
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1. Maybe, but no often. No, performance is great, like new lens I guess.

2. Yes, and its many. Most of them in front of main block (under first front elements). And one in the first back element (near sensor) but I never want to disassembling whole lens, I cant do it.

3. No, no Canon service near, unfortunately. I see video in youtube and its look pretty easy to pull out front element and clean smaller main block of the lenses, but it's all about old EF lenses.

Yes, I can wait with cleaning, its not a problem, but I've notice that more and more dust visible IN THE lens... So, after another year I should to clean it anyway, I guess. :(
 
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Feb 10, 2021
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I would put money on that being on the sensor, not in the lens, especially as they are towards the edge of the sensor and you say you've cleaned it......

Have you tried with another wide angle lens at f/16 ?
Yes, I have 15-35... I've tested it, no spots. But tomorrow I can repeat (have no time today) to be sure.
But why on 35mm I didn't see any spots ? I guess its because some part of edge of lens dont using when shooting on 35mm. No ?
 
Feb 10, 2021
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And one more... I have 15-35 for 2 months and want to buy RF 70-200 f2.8 next month... And this situation with dust scaring me... Is this telescopic constructions of new Canon lenses will be always a "dust eater" Or its just with "cheap" 24-105 ?
 
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Mt Spokane Photography

I post too Much on Here!!
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Mar 25, 2011
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Check the rear element of the lens. If its dirty, that will show. Otherwise, internal lens dust really is not a issue to images. The sensor is the most likely to be the issue by a huge factor. Cleaning a sensor by using a blower is good, but oil spots can also get on a sensor and be very difficult to remove, even with a wet cleaning. They tend to make the transparent blobs in the photos.
 
Feb 10, 2021
7
0
Check the rear element of the lens. If its dirty, that will show. Otherwise, internal lens dust really is not a issue to images. The sensor is the most likely to be the issue by a huge factor. Cleaning a sensor by using a blower is good, but oil spots can also get on a sensor and be very difficult to remove, even with a wet cleaning. They tend to make the transparent blobs in the photos.
ok, i'll check sensor one again with good light.

Thank you.
 

Ramage

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CR Pro
Aug 27, 2019
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If you really want to see spots use LR to edit, take a shot against a white background and crank the dehaze. If you have spots they will be as clear as day. :)
 
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Feb 10, 2021
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Check the rear element of the lens. If its dirty, that will show. Otherwise, internal lens dust really is not a issue to images. The sensor is the most likely to be the issue by a huge factor. Cleaning a sensor by using a blower is good, but oil spots can also get on a sensor and be very difficult to remove, even with a wet cleaning. They tend to make the transparent blobs in the photos.
You're right, there is few big particles of dust and many small on the rear element of the lens :( Observing my 24-105 with a lamp and I'm quite shocked how many dust EVERYWHERE in the lens that only 2 years old. :(
After cleaning sensor made a test shots with different lenses.
Attaching 2 shots on 24mm F22 from rf 15-35 and 24-105. Blobs very noticeable.

Seems I must going to Service sometime... :cry:
 

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