Cleaning mud off CPL without scratching it

[tenohfive]

Whilst wandering around with the daughter hanging from my front and camera hanging from my back I managed to lose a lens cap and my Hoya HD CPL without noticing. Fortunately I found both separate in the mud 20 minutes later. The CPL got a mud and leaf bed landing and it's pretty filthy now. I'm hoping it's not scratched as it cost £70.

So what's the safest way to clean it? I was thinking of running it under the tap with warm water to get rid of the grit, then use some sort of alcohol based cleaning product - would that work, and if so any recommendations for the latter?

[Simpo Two]

Running water sounds good to me - then dry and finish off with a 'hurr' and a lens cloth. Glass is hard so don't be too timid.

[LongQ]

Simpo Two said:

Running water sounds good to me - then dry and finish off with a 'hurr' and a lens cloth. Glass is hard so don't be too timid.

This or similar.

If that fails try a light sandblasting.

Polarisers, that I have seen, often have some light grease like lubricant in the moving components - partly for damping the movement. If yours has try not to eradicate it. It will have a purpose.

Having a CPL unscrew by itself is unusual. Did it get any assistance?

[tenohfive]

LongQ said:

Having a CPL unscrew by itself is unusual. Did it get any assistance?

None, the camera had been slung over my shoulder for about a mile as I walked along. I can never really tell when the filters are on securely - it doesn't lock into place, it just spins. I'm assuming that's normal?

[nellyleelephant]

LongQ said:

Simpo Two said:

Running water sounds good to me - then dry and finish off with a 'hurr' and a lens cloth. Glass is hard so don't be too timid.

This or similar.

If that fails try a light sandblasting.

Polarisers, that I have seen, often have some light grease like lubricant in the moving components - partly for damping the movement. If yours has try not to eradicate it. It will have a purpose.

Having a CPL unscrew by itself is unusual. Did it get any assistance?

Wouldn't the risk of getting water 'trapped' between the two bits of glass be a bit high?

[RobDickinson]

nellyleelephant said:

Wouldn't the risk of getting water 'trapped' between the two bits of glass be a bit high?

What two bits of glass?

[LongQ]

RobDickinson said:

nellyleelephant said:

Wouldn't the risk of getting water 'trapped' between the two bits of glass be a bit high?

What two bits of glass?

CPL.

Partly the reason for the 'grease'.

[RobDickinson]

LongQ said:

RobDickinson said:

nellyleelephant said:

Wouldn't the risk of getting water 'trapped' between the two bits of glass be a bit high?

What two bits of glass?

CPL.

Partly the reason for the 'grease'.

There is only one 'bit of glass'.

[LongQ]

tenohfive said:

LongQ said:

Having a CPL unscrew by itself is unusual. Did it get any assistance?

None, the camera had been slung over my shoulder for about a mile as I walked along. I can never really tell when the filters are on securely - it doesn't lock into place, it just spins. I'm assuming that's normal?

It should lock on the threaded section, spin (sort of) on the front section. You have to ensure you have a good grip on the threaded section to make it lock. Then it can be a challenge to get it off again.

Lens cap designs are a different matter - although I see that Canon are changing the design of their lens caps to make them easier to use if the lens is deep inside a filter hood (for example).

[nellyleelephant]

RobDickinson said:

nellyleelephant said:

Wouldn't the risk of getting water 'trapped' between the two bits of glass be a bit high?

What two bits of glass?

Having just looked at a couple of mine, you're correct, I'd always assumed there were too glass elements working together.

I'll shut up now!