What is averted vision

[PRICEMAN]

Sorry,

A really basic one but am not quite sure what it means.

Is it when you done look directly at something or when you look at something, look away and then look back again.

I think I was doing it last night when looking at M57 because one minute it was really blurry, then next it would be clear then back to blurry again.

Can someone help me with this and the best way to do it

Thanks Guys

Leigh

[Moonshane]

hi Leigh

Averted vision is looking just to one side/above/below an object (it's different for different people - find your own best position) and this reveals more detail or e.g. one of Saturn's moons will suddenly pop into view.

this works as the low light level, monochrome rods in your eyes (which are what you use when observing at night and hence to a large extent the lack of colour in faint DSOs) work best 'side on'.

try it with Saturn. look at and around the disk and moons will appear that were not visible with direct vision.

hope this helps a bit.

[rocketandroll]

There is a patch at the centre of your retina where the optic nerve exits the eye that is less sensitive than the rest.

If you look slightly to the side of a small/feint object you will actually be using a more sensitive part of your eye than if you look directly at it so should be able to see more detail.

Try it... It really works!

Ben

Sent from my GT-I9100 using Tapatalk

[MorningMajor]

Have you seen this thread

A great explanation

[alowen]

Yes, i use this method for DSO's. Took a while for me to suss it but works great now.

Al

[Donkeiller]

You can also try slewing the telescope a little- the movement makes it really "pop out".

I was looking at M57 two nights ago and this also works well.

Something to do with the eye being a very good motion detector.

[cervesca]

same effect (moving the object) also happens with faint satellites!

[Ad Astra]

Hi Leigh,

The retina of your eye has two kinds of cells - Cones, which are sensitive to color, but aren't very light sensitive (need lots of light to function); and Rods, which are good at sensing edges and are up to 1000 x more sensitive to light than cones when properly dark adapted.

Cones are mostly in the center of the retina (where the light falls when you look straight at something). Rods are mostly concentrated around the periphery of the retina.

Looking slightly away from a target causes the light to fall on the region rich in rods - this allows you to pick up very faint objects with low contrast and surface brightness (remember the high light sensitivity?). These cells don't see color, though - this is why DSO's appear to be in black & white all the time unless you look through a real monster of a scope (18-inched or larger). The real big scopes provide enough light to activate your cone cells - smaller scopes don't.

The brain also comes into play, moving objects are more easily detected. Like the Tyrannosaurus in Jurassic Park, our vision is largely based upon motion - especially with rod cells at night when the color signal from cone cells is almost totally absent. This is why slewing or even tapping the scope to make it shake a bit, can improve your perception of faint objects.

I hope that helps a bit,

Dan

[Chris16373]

And it really helps, tried it on M13 last night and it was a difference...not a big one of course in my scope...but still!

[PRICEMAN]

Thanks for taking the time to explain that to me guys. Will give it a go tonight. Looks like it's going to be a clear one in sunny Liverpool

Regards

Leigh