Charts or apps and night vision?

[westmarch]

I frequently see posts that decry the use of apps or astronomy VDUs on the basis that any display, no matter how dim or red, will ruin your night vision. Presumably those who use print outs need a red light to see them.  

Has anyone conducted a rigorous assessment, with a photometer, to compare the light output of the two methods?

Or is this a bit like wine tasting? 🤔

John

Edited June 23, 2020 by westmarch

[mikeDnight]

Any amount of light red or otherwise is damaging to true dark adaption, however, unless the observer knows exactly the target it is often unavoidable to check charts of one form or another. The difference between electronic and paper charts is largely academic as to see a chart well, the lighting needs to be bright enough to read coordinates and numerical designations. I think all that can be done to compensate for loss of dark adaption, is to observe the target for an extended period (20 minutes or more) after the red light has been switched off. That way a measure of dark adaption can be regained.

[SteveWolves]

There is a topic on here about red torches somewhere, the problems seem to be many are far too bright and people do walk about with them like lighthouses and the same applies to aps its more how you use them to minimise loss of dark adaptation.

[Waddensky]

All light will more or less affect your night vision. If you have a device with AMOLED screen, the 'leakage' of light is mimimal because only the 'lit' pixels will light up and the dark pixels are effectively off (no background lighting). Astronomy torches have the ability to dim the light to a very low level. I've never done measurements but it would be interesting to compare the two.

[niallk]

I used to use an app in night mode red and the screen set to minimum dimness.

Now i plan with charts & an app, write a list in black marker on white paper, and use an LED torch at the scope- which can be set very dim, plus i have Argo Navis with again a very dim alpha numeric display - it is thoughtfully designed.

I find this arrangement much better for me for preserving night vision vs using an App at the scope, though I'm sure looking through some attenuating screen filter could help.  Or keeping your observing eye closed - pirate patch ?😂

[Jiggy 67]

Light pollution (from any source) is never gonna go away and will always be present. It is also unavoidable to produce it yourself with red torches, apps etc. It’s something we all just have to live with, the trick is to minimize it as much as possible.

I use apps at the scope which are red filtered through the app, but I always found it annoying when accessing the app, the phone home screen projected white light before I could get to the app. Someone on this forum pointed out that in the setting of an iPhone you can change the backlight from white light to red so all screens on the phone including the home screen are red

[Paz]

I started out with charts until I discovered sky safari and without intentionally planning to I stopped using charts and now only use sky safari in the field.

I put red film over my phone as this helps but but most importantly I only use my non observing eye to check out the map so that my observing eye stays dark adapted.

[popeye85]

Give me a atlas any day of the week!!!

 

To me the greatest joy in stargazing is spending the day planning several hops then going out under the sky and doing it for real. 

Half the point of stargazing is escaping modern technology!!

[John]

1 minute ago, popeye85 said:

....Half the point of stargazing is escaping modern technology!!

[andrew s]

You could use an eye patch on your observing eye and use the other for reading maps.

Regards Andrew 

PS remove eye patch when observing!

Edited August 12, 2020 by andrew s

[andrew s]

1 hour ago, popeye85 said:

Half the point of stargazing is escaping modern technology!!

So no fancy new technology glass APO refractrors or eyepieces then.

Regards Andrew