It would be Once every 6 months or even to a year till I've a BD full with photos so internet storage with monthly fee isn't worth the money.
Also your storage is in the hands of others so what happends when they will go bankrupt?
I'm always sceptical with those things so don't worry, i just don't like giving my photos out of my hands.

ps. you always go off topic you know, we started with DVD and BD and now it's about so what every storage method.

Glad to hear that Gwyn, that you have no problems.

Delamination occurs mostly when there is stress between the two materials. it might be that the glass of the filter expands more then the coating when it heats up. Not usre if that's the problem it can just as easily be something else like manufacutring malfunction.

No such thing with my 8 months old B+W MRC and 2 months old B+W Käsemann MRC.
Hoya probable use other coatings and such but still are you sure it is okay?

I now use harddisk as well but I've some photos I simple want a third copy off so DVD or BD would be perfect then. I was thinking of using DVD but for 20gb I would end up with 5 DVD's so 1 BD looks like a better option if it proves more reliable then DVD.

Greytop, DVD+R are better for long storage then -R because of the way they are written but it also depend on the make how long they last as you've experience.

The BD in your link looks really good but really expensive though and not worth the money I believe.
Verbatim has always being good to me and a 5 pack BD is £21.34.

I know their DVD are very good but I've no idea how their BD are, they only say Extremely long archival life... yeah not very helpful

Amin the place to find the meaning of such words is here link
It even has the smiley

:-s = = confused

Am I the only one with this idea here?

I was first thinking of burning them on DVD but since they are all raw files that means I need a lot of DVDs and using dual layer would help to shrink the numbers but they are also more expensive and quite close to the price of BD so not really a option I believe.

I know some here back up on DVD, can I ask how many DVDs you have?

I can see that a MF pentax can be atractive for starting professionals though and even some oldies might go back to Pentax simply for the joy.

About the sensor, it's going to be most likely a Kodak, the KAF-31600 with 31,6MP was last mentioned but Kodak in the mean time have brought out the KAF-39000 & KAF-50100 with 39MP & 50,1MP so who knows what end up in the 645D.
It's all about where they want to place themself.
50,1MP sounds very interesting though, it sounds a lot but the pixels are more then 50% larger then that of the K20D & K7 sensor if I'm correct.

I believe the shuter is tested for 100,000 clicks so surely still good for second hand.

I'm seriously thinking of using them for storage purpose, since the price has come down quite a bit last year and I rather have store 1 BD disc instead of 5 DVDs.

DVD+R goes up to 70 year reliably but you have a good change high quality DVD still work after 100 year when stored correctly.
Does someone know what the lifetime is of todays BD?

I've searched the web but couldn't find anything conclusive.