Strange things going on with my eyes..

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Alastair Moore
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Strange things going on with my eyes..

Postby Alastair Moore » 20 Feb 2013, 14:41

So I re-sealed/re-light proofed my bathroom this afternoon as I've been concerned about leaks and the pain in the arse that it's been to make sure the bathroom door is full light-tight. I took my thick doubled up sheet I've been using (which is definitely light-tight) and have lined the top and sides with velco from top to bottom. There is no light coming through that door, I absolutely know it.

However, I'm not sure if it's my imagination running wild or something else but it feels like I can very, very slightly see my hand as I wave it past my face. Even stranger is when I close my eyes shut, it feels like I can still very, very slighty see my hand waving past my face. Perhaps I'm expecting to see it and so my brain is telling me I can see my hand waving past my face.

What's going on? Am I going mad? For all intensive porpoises, it's completely dark. Are there any other tests I can do to make sure the bathroom is light tight?

Cheers,

Alastair

ps. two packs of this - http://www.officeworks.com.au/retail/pr ... ro/ES42719

Lachlan717
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Joined: 03 Aug 2012, 16:49

Re: Strange things going on with my eyes..

Postby Lachlan717 » 20 Feb 2013, 17:33

Without getting too boring, you have some rhodopsin molecules becoming “bleached” in your eyes' rod photoreceptors. Put simply, you have an after-image. It should reduce in a few minutes…

If you're worried about light leak, leave a film holder half open in the room for an extended period of time. Once processed, there should be no noticeable difference in transmission in the finished neg.

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Maris
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Re: Strange things going on with my eyes..

Postby Maris » 21 Feb 2013, 10:10

Lachlan717 wrote:Without getting too boring, you have some rhodopsin molecules becoming “bleached” in your eyes' rod photoreceptors. Put simply, you have an after-image. It should reduce in a few minutes…

If you're worried about light leak, leave a film holder half open in the room for an extended period of time. Once processed, there should be no noticeable difference in transmission in the finished neg.

Thanks for the tip on the rhodopsin molecules. I always wondered where the after-image came from. I sometimes do one or two hour sessions in "absolute" darkness and my view of things settles to a very dark grey that looks the same eyes open or eyes shut. I guess that is caused by the brain automatically turning up the visual gain control trying to find a photon where there is none.

Lately I've stopped worrying about minute light leaks like the faint glow under the darkroom door or the vague gleam in the corner of the blacked out window. I climbed into my darkroom sink (when it's dry, natch) and lay full length in it with my head where the developer tray goes. Because I couldn't see any of those tiny light leaks I figured the film could not see them either. And I did the half open film holder test to prove it.

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Alastair Moore
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Location: Darwin, Australia
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Re: Strange things going on with my eyes..

Postby Alastair Moore » 21 Feb 2013, 12:46

Lachlan717 wrote:Without getting too boring, you have some rhodopsin molecules becoming “bleached” in your eyes' rod photoreceptors. Put simply, you have an after-image. It should reduce in a few minutes…

If you're worried about light leak, leave a film holder half open in the room for an extended period of time. Once processed, there should be no noticeable difference in transmission in the finished neg.


I'm going to give this a go. Top tip! Thank you.


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