HI If this is not the DG type what you do is to remove the name ring you can pleel it of it will restick under the name ring you willsee two holes to use a compus to undscrew this ring do not put to much presher on the ring when unsewing it next you will be able to unscrew the front element just clean and blow out the dust out then rescrew all .
To do a good job yes! You can try blowing out with a can of high pressure air but it will not get it all! Take apart and only use a micro fiber cloth to clean and handle lens! PLEASE rate my response to your question Thank You!
If a DG macro you need to unscrew the front ringed cover to reveal screws (this piece shares the same thread that you would use for a filter, I am not refering to the outer rim! - I am not sure the official way of doing this as there are no location holes, I think they might use a mating tool which has enough friction and grip to get it turning in Sigma service centers but don't know for sure! However, a few specs of dust might annoy but are not enough to affect picture quality so probably as well to leave it alone :)
Answers & Comments
HI
If this is not the DG type what you do is to remove the name ring you can pleel it of it will restick
under the name ring you willsee two holes to use a compus to undscrew this ring do not put
to much presher on the ring when unsewing it next you will be able to unscrew the front element
just clean and blow out the dust out then rescrew all .
To do a good job yes! You can try blowing out with a can of high pressure air but it will not get it all! Take apart and only use a micro fiber cloth to clean and handle lens!
PLEASE rate my response to your question
Thank
You!
If a DG macro you need to unscrew the front ringed cover to reveal screws (this piece shares the same thread that you would use for a filter, I am not refering to the outer rim! - I am not sure the official way of doing this as there are no location holes, I think they might use a mating tool which has enough friction and grip to get it turning in Sigma service centers but don't know for sure! However, a few specs of dust might annoy but are not enough to affect picture quality so probably as well to leave it alone :)