Dust Issues on internal NDs?

[David C. Williams]

Anyone else having issues with dust and grit getting behind the protective glass, and onto the NDs and so on?

In the past 5 months we've had 4 bodies returned for cleaning and many days of re-shoots as a result of dust specks. It seems the optical block area is not sealed very well.

Worse still, the dust often moves as you use the NDs. You can check it as clean, ten minutes later there's a spec, later it's gone.

A local rental house we get substitutes from when ours are in the shop also has had many issues. We really don't know where the dust gets in, and you cannot clean it obviously without dismantling the camera...

[Nate Weaver]

Time to start checking the gate again.

[Peter G. Johnson]

Hooray! So I'm not irresponsible after all and I'm not seeing things. Yes, dust gets in behind the optical block and it doesn't matter how fastidious you look after the camera. It is really annoying!

It was first raised eleven months ago.
See: http://www.dvinfo.net/forum/sony-xdc...-cleaning.html
I also wrote about this happening back in July.
See: http://www.dvinfo.net/forum/sony-xdc...ny-pmw-f3.html

The optical block is a blue tinted, plastic cover with four small screws. I've removed the cover once to inspect behind it and there is no rubber seal or anything like that; just plastic onto metal! The ND filters are three very thin pieces of glass, glued into a metal frame. I always believed it looked cheap.

How much does it cost to clean the insides? I'm sure that service is not under warranty.

[Andrew Stone]

Just a thought. If dust is getting in through the ND switch, if it doesn't affect heat dissipation, place a piece of cloth gaffer tape over the switch until it needs to be used.

[Kirk Miller]

I've also seen dust inside the optical port of my camera and have been considering sending it in. I fortunately have not seen any evidence of dust in the picture yet. Has anyone dealt with Sony Service about this issue?

[David C. Williams]

It really looks like this will be a recall issue to seal everything properly. It's just not fit for use otherwise.

The dust will become more prominent as you stop down, and use shorter focal lengths.

Our last body had is having the entire ND mechanism replaced under warranty after the shop messed up the cleaning and sent our F3 back in worse condition than when we sent it in for cleaning. Finger prints on the NDs, and they blamed us believe it or not...

[Kirk Miller]

Have they been cleaning it for you under warranty?

[Peter G. Johnson]

I enquired a few months ago about getting the insides cleaned (behind optical block, ND filters behind and front etc). The cost is $100 per hour, plus parts (if necessary.) Fortunately the dust on my PMW-F3 is not at all detectable on the images, so I just try to ignore it. It is frustrating however to see it there on the ND filters every time I go to change a lens, and not be able to do anything about it. This was from Day 1, mind you!

If you look at the underneath of the front of the camera, you'll see one screw holding in what looks to be a latch. I wonder if that's how Sony removes the ND filter slides to clean them?

[David C. Williams]

And two more bodies are down due to dust inside the optical block. This really is a serious issue for us. Many tens of thousands is extra post costs, body rental, down time, reshoots. Reliability is everything in production.

Really very disappointed with Sony here. How can dust possibly get INSIDE a properly designed block? It's obviously not sealed well..

If this is happening on every larger production I can see Sony getting a lot of angry producers knocking on their doors.

[George Griswold]

Looking at the service manual for the F3 I don't see an exploded diagram to access the ND filter which is inside the front block. Doesn't mean you can't access it, but getting to the front block involves stripping off 12 external panels, handles and boards. There is a ND seal and conductive tape (static control) listed on the exploded front panel diagram, but sounds like it is not up to the job. A strip of camera tape over the selector in dusty conditions would be a good idea.

The service manual is not like other Sony broadcast manuals with schematics and board level repair information. The repairs are basically board swaps and the manual describes how to get to each one. The service menu is pretty short.. no big surprises there.

[Peter G. Johnson]

You couldn't even consider trying to clean the ND filters via the optical port. It's just not accessible enough. As mentioned earlier I removed the cover once to inspect what is behind it the port. There are no seals, just plastic onto metal. Behind the optical port the ND filter is exposed to the open air. It is such a crappy design.

I think the ND filter is removed by dropping the assembly out the bottom of the camera. I couldn't imagine you would have to take the camera to bits in order to get at the filter. It just doesn't seem practical. I do however like the idea of a camera where entire modules can be replaced or cleaned. The exploded views of the F3 look quite simple, however I'm sure there is more to it than that.

My advice for any users who are experiencing dust behind the optical port or ND filters on their PMW-F3 (and this is through frustrating experience) is just forget about it! It's very highly likely you won't detect it. I tried an experiment where I removed the PL mount, turned the camera on and shone a bright light at the port. I also had the camera plugged into a large television so I could see very clearly what image it was receiving, which was just a blurred light, and at the same time, flicked very slowly through the filters to see if I could detect any dark areas or blemishes on any of the slides (etc.) Nothing!

Be guaranteed if a normal layman like you or I takes our camera to be cleaned you can forget about claiming it on warranty. You'll be charged a fee and blamed for the dust. David Williams, however has some muscle behind him because of the potential for lost business.

[George Griswold]

Hi Peter, the best way to reveal any dust is to put a longer lens stopped all the way down... that narrows the projected light. Having no lens or one that is wide open is less revealing. No lens at all admits light at wide angles so can hide dust spots (they need to cast a shadow on the imager or ND filter) that would possibly show up on a real world shoot.

[Peter G. Johnson]

Enlightenment! I spoke to a Sony support technician today. Dust is a real and genuine issue with the F3 and in most circumstances will be covered by warranty, and as advised by George Griswold, is most prevalent when stopping down in a bright environment. It requires the unit being sent to particular service centers. In the case of Australia, that's Sony in Sydney, where the front of the camera is dismantled, cleaned in a specialized environment and then properly sealed somehow??

I also learnt that the ND filters are indeed made of a very thin glass and there is nothing between the filters and the sensor. Finally I asked, what is the purpose of being able to remove the optical port? Apparently it is coated in a special material which ensures that only the correct type of light can reach the sensor, sort of like a UV filter. Eventually it needs to replaced as if can lose its effectiveness over time.

The down side is of course having to send the camera to another state, being without it for a up to a month perhaps, not being able to interact with the technician other than by phone and then there's always the possibility of copping a fee anyway.

I use my F3 purely for domestic purposes and for all intensive purposes the dust doesn't show up in the end result, so I think I'll just sit on the fence for a while and see how big an issue it becomes. Certainly it's really p*@#ed me off because the camera is so expensive, but what will come of it over time?