Eye adaptation!

[PortugueseGazer]

Hello guys, I have 3 questions.

1-How long should I wait until my eyes adapt to the night sky?

2-Is it true that when our eyes are adapted, it only takes one look at a street lamp to destroy said adaptation?

3-Does a binocular need to cooldown before I start gazing like a telescope?

Thanks in advance.

[paul mc c]

1.Abuut 20 mins.

2.Yes a light can ruin your night vision.

3.Binoculars are ready to go.

[ronin]

Best if they are given some time but eyes tend to react fairly fast, they changed fast initially then slowly get better.

Yes a bright light will make them close down, but that is what they are supposed to do, they will open up again.

Never heard of anyone cooling down binoculars, but being compact I guees they lose heat fairly quick.

I wouldn't worry too much, the idea is to observe and even if not the best you may as well get going as soon as you can.

[Stu]

I think that it depends where you are observing as to just how important this is. When I am at home, there is so much light pollution around that it is impossible to get fully adjusted.

When at a dark site, it can make the difference between seeing and not seeing an object.

There are two processes at work with dark adaptation. Firstly your pupils dilate or contract, and this happens very quickly as you move between light and dark.

The other is the chemical process as Rhodopsin, which gets bleached out in bright light, regenerates in the photoreceptors. This happens within about ten minutes in the cones, but up to half an hour in the more sensitive rods.

I have experienced the effects of this quite clearly when trying to view the Veil in a 4" scope at a dark site. One night I used my mobile to check something, and could only see certain parts if it even 30 mins later. The following night I was very strict about adapting my eyes, and could see the whole lot, including Pickerings wisp.

It is well worth enduring your eyes are as adapted as possible, and avoiding smart phones or tablets. Maps and a red light torch work very well.

Stu

[scarp15]

And if / when you look at the moon through binoculars, your eye will require a brief period of time to re- dark adapt.

[PortugueseGazer]

Thank you guys for the quick replies.

The reason I opened this topic was because I spend most of my time at my backyard, which is dark when looking south ( no street lights, just fields), but when I gaze north, I get bombarded with street lights. I usually spend around 10 minutes gazing to the north sky but it seems only a couple seconds are enough to ruin adaptation..

Well, it seems my new strategy will be starting my night observations facing north and spend most of my time facing south where I get the most darkness.

Thanks guys, you are great

[Stu]

That makes a lot of sense, good luck :-)

[PortugueseGazer]

That makes a lot of sense, good luck :-)

Thank you

[itmo]

the best part about a 12" is that I dont need no dark adaptation  

basically in the first 20 seconds or so your eyes dilate , in the first 5-10 minutes or so your eyechemistry gets maxed out for colorvision and up to 30-40 minutes before the black and white nightvision is maxed. 

 http://webvision.med.utah.edu/imageswv/KallDark1.jpg

[bmc]

hi, 

at a rush allow 20 mins for your eyes to adapt to the dark, running best at an hour. if you get any light, you need to start again to achieve full dark adaptation. when i'm in the house, i pop on an eye patch over the eye i use to sight, ( much to the merriment of my girlfriend) before i go out. and keep it handy if i need to pop indorrs.

Bernie.