UR/Pro filters for C5050Z

[Whitetip]

Just took delivery of a GR filter to fit on the end of the PT015 .

One thing has me worried with regard to the accompanying leaflet . I quote :

" When a GR filter is used on a Nikonos camera the filter must be screwed into the front of the lens when the camera is in the water to prevent possible implosion of the filter ."

I'm wondering if this affects the Nikonos only or if its the normal drill for someone with my kit set - up . Do I screw the filter on before entry , or when in the water ? Surely this would mean there is a sandwich of hydroplankton between the two optical surfaces .

Anyone out there using the C5050z + PT015 & Ur/pro filters , please feel free to let me know your opinion .

Also , what's your angle on keeping the filter clean



Safe diving

 

[sparky30]

I don't have a filter.. but I do have a C5050 in a PT-015 housing..
I think the reason for attaching the lens underwater on a Nikonos is that they are trying to get water between the lensport and the filter. .if you attach it at the surface, you would have air trapped between the lens port and the filter.. a depth it would shatter and break from the pressure..
As far as I know, on a PT-105 (I don't have mine in front of me and I'm too lazy to get up and look) there is a small whole in the red ring at the front of the lens port.. That's where the threads are to attach the filter.. The reason for thw whole is to allow water between the lensport and whatever filter/additional lens you attach.. That should eliminate the problem of implosion..
I could be wrong.. since I haven't tried it myself..So you should be OK to attach the filter on the surface..

 

[TedJ]

First,
There are indeed holes in the red ring at the end of the housing lens. However, it is possible that the filter threads are thick enough to block the holes and therefore block the ability of trapped air to exit between the filter and the housing lens. Make sure the holes are not blocked.

Second,
I would put the lens on dry, hop in the water and make sure there are no air bubbles trapped between the filter and the housing lens. If there are, simply unscrew the filter and allow them to escape. This is commonly known as "burping" the lens.

I had a clear filter on my PT-015 to protect the housing lens for awhile and decided that it was too much of a pain to have to go through this procedure every time I got in the water so I eliminated the filter. Haven't used any other type of filter.

 

[blacknet]

Hello,

Why use a filter? What purpose do you hope to achieve with one? David Doubilet has used some filters in the past, i think it was an amber filter. I was taught how to not use a filter and get the same results. Filters will hinder light and light is very critical.


Ed

 

[wetman]

I've got a UV tiffen filter on mine just to protect the port as well and there has been no issue with air bubbles - the holes work quite well.

steve