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theMusicMan
11th May 2008, 07:26 PM
Hi All

Went out today with the family to a wonderful place called Ogmore by Sea. There's almost everything there within a few miles; from miles of sand dunes, cliffs, sandy beaches, rock pools, grass moors to set up picnics on, there's even a small river that leads into the sea and at low tide you can cross it and play in it. Wonderful place to be honest.

Anyway, I was taking some shots of Heather and her friends playing in the water and the sand, and when I processed these I noticed that there was a speck on each image. Investigation yielded some muck on the ND4 filter I was using, and I'd like to ask a simple question - how does one best clean filters...? Is there a prescribed or accepted method of doing this...?

All advice greatly appreciated, many thanks.

shenstone
11th May 2008, 09:24 PM
Hi All

Went out today with the family to a wonderful place called Ogmore by Sea. There's almost everything there within a few miles; from miles of sand dunes, cliffs, sandy beaches, rock pools, grass moors to set up picnics on, there's even a small river that leads into the sea and at low tide you can cross it and play in it. Wonderful place to be honest.

Anyway, I was taking some shots of Heather and her friends playing in the water and the sand, and when I processed these I noticed that there was a speck on each image. Investigation yielded some muck on the ND4 filter I was using, and I'd like to ask a simple question - how does one best clean filters...? Is there a prescribed or accepted method of doing this...?

All advice greatly appreciated, many thanks.


Bottom of a T Shirt works fairly well in a crunch, but the standard apprach is to use a lens cloth/brush/Pen (your preference) working in circles from the centre out (as grit tends to get lodged in the corner where the class meets the frame and you don't want to scratch it across your glass).

If I had a significant speck on the glass I would remove that first with some breath on the glass and then a fingernail in a cloth if necessary and then follow the process I just described

Regards
Andy

David M
11th May 2008, 09:57 PM
Plastic or glass?

theMusicMan
12th May 2008, 05:00 AM
David - I am certain they are Cokin Plastic filters.

Andy - thanks for that - so there's no real worry here then, just care and the usual yeah?

DTD
12th May 2008, 07:07 AM
I use a brush or blower first to remove any grit, as obviously grinding this into the filter surface with a cleaning cloth will scratch it.

I know purists don't like them, but I'm paranoid about scratching the front element, so always fit a filter.

If you're really into cleaning, here's a link to a Zeiss booklet about cleaning microscopes, which gives the gen on lenses (thanks to someone on the Leica User Forum for the link):

Link to PDF document on Leica forum (http://www.zeiss.com/C1256D18002CC306/0/1205E8CBD68054EAC125701500404705/$file/46-0009_e.pdf)

theMusicMan
12th May 2008, 07:08 AM
Hi DTD - it was the Cokin removable filters I was asking about how to clean... :)

Thanks for the link, I'll have a read through this later.

David M
12th May 2008, 08:48 AM
As plastic filters scratch far more easily than glass I clean them with warm water and a mild detergent. If it's muck as you describe I'd dampen the spot with water and detergent using a soft brush and leave it for a couple of minutes before loosening the spot with the brush under running water.

Once the spot's off I'd clean the rest of the filter in a similar way and dry with a soft, lint free cloth.