Thanks very much for this,i've just bought this lens(very cheaply) but it had a fault,that being a small scratch 1cm in from the outside edge,plus dust inside,the scratch doesn't seem to show up much on my photos,i hear its possible to polish them out,would you recommend this? I dont fancy doing this,so i can live with it,still,it'll need a good clean anyway
I can't unscrew the front lens cover ring. It's stuck. The threads don't seem to be damaged but it's just not moving. You don't seem to be applying much pressure, so I don't think it's that I'm not strong enough. Do you have any advice?
In the end I carefully drilled two small holes in the ring on opposite sides and used a lens wrench to get it started. I was then able to finish off with the rubber opener. Once I cleaned off the fungus and reassembled the front element, I covered the underside of the holes with a small piece of gaffer tape before screwing the ring back on. I would only do this as a last ditch effort though. Also, if you have a small keyboard vacuum use this to remove the aluminium dust from the drilling. Or use a lens blower. Don't try to clean with a cloth or you may damage the glass.
Thank you very much for the info, drilling holes could solve this problem, but also, my other idea would be to use a two sided adhesive tape and a thick drinking glass of the same diameter of the ring to remove it.
A clear and concise explanation. Thank you!
Glad it was helpful!
thank you so much for this video but can you separate the glass on the front element? my lens got fungus inside the front element. thanks
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Do know if it's the same way to take apart for the original Sigma 17-70 Non OS model.
This is the original, first Sigma 1770mm without OS.
Thanks very much for this,i've just bought this lens(very cheaply) but it had a fault,that being a small scratch 1cm in from the outside edge,plus dust inside,the scratch doesn't seem to show up much on my photos,i hear its possible to polish them out,would you recommend this?
I dont fancy doing this,so i can live with it,still,it'll need a good clean anyway
Don't polish the glass, it will ruin the image quality.
The scratch will not be seen on the taken photos.
1:40 what is that? and how can i replace it
Which part? At 1:40 I just pick up the lens, and start to disassemble it.
Thx u!
You're welcome!
I can't unscrew the front lens cover ring. It's stuck. The threads don't seem to be damaged but it's just not moving. You don't seem to be applying much pressure, so I don't think it's that I'm not strong enough. Do you have any advice?
In the end I carefully drilled two small holes in the ring on opposite sides and used a lens wrench to get it started. I was then able to finish off with the rubber opener. Once I cleaned off the fungus and reassembled the front element, I covered the underside of the holes with a small piece of gaffer tape before screwing the ring back on. I would only do this as a last ditch effort though. Also, if you have a small keyboard vacuum use this to remove the aluminium dust from the drilling. Or use a lens blower. Don't try to clean with a cloth or you may damage the glass.
Thank you very much for the info, drilling holes could solve this problem, but also, my other idea would be to use a two sided adhesive tape and a thick drinking glass of the same diameter of the ring to remove it.
How can I do to disassembly sigma zoom 55-200 af B2 1:4 - 5,6 trhough frontaly lens?
I don't know, I haven't done that before.