A Few Projects

Show and tell for your homebrew nv projects. DIY 'Stickies' here too.
lightmesser
Posts: 468
Joined: 09 Jan 2014, 01:19
Location: Eastern Europe

Re: A Few Projects

Postby lightmesser » 04 Jan 2018, 00:07

TNX,

We tried that method years ago... It significantly reduces visible red light but it does not eliminates it.
There is whole thread about that but it is hard to find it :)

Which one do you use 850 or 940 IR pass filter?

Edit: there is thread here but photobucket pictures are lost :thumbdown: viewtopic.php?t=7885

Texan
Posts: 17
Joined: 30 Dec 2017, 22:49
Location: Texas

Re: A Few Projects

Postby Texan » 04 Jan 2018, 02:03

I have not tried it on a scope build. I used to use ir pass when I was messing with building a multi-touch table display many years ago.

Texan
Posts: 17
Joined: 30 Dec 2017, 22:49
Location: Texas

Re: A Few Projects

Postby Texan » 04 Jan 2018, 02:20

I read that thread and it was kinda hard to tell without the pictures, but it looked like they where putting the ir pass on the torch. What I did with the multi-touch table was to put the ir pass in front of the camera so that all the camera could see was the infrared.

Question on board etiquette, is it ok to start a thread as I start a build and update it as I move along?

I am going to build a raspberry pi scope with GPS, 9dof imu, maybe barometric, light sensor to trigger ir cut, etc. as close to ATN as I can get without dropping frame rate to low.

lightmesser
Posts: 468
Joined: 09 Jan 2014, 01:19
Location: Eastern Europe

Re: A Few Projects

Postby lightmesser » 04 Jan 2018, 09:36

Texan wrote:I read that thread and it was kinda hard to tell without the pictures, but it looked like they where putting the ir pass on the torch. What I did with the multi-touch table was to put the ir pass in front of the camera so that all the camera could see was the infrared.


Why would you do that? You can't see nothing after that mod or in other way you will kill cameras night light gathering capability.
We are in constant "competition" of finding best and most sensitive camera which gives clear image under certain night conditions (moon, half moon, stars) + at dusk and dawn... Adding that filters on camera sensor will significantly downgrade camera performance... Sure it will work with IR lights if you want to use them all the time like on ATN X sight which indeed has so terrible sensor you got to use IR all the time :)

And yes that thread was about reducing red dot or red glow signature from the torch.

Adding that filters on scope or camera at daytime has sense cause camera will render colors better after we switch to color mode or auto mode in some cameras since we removed IR filters from their sensors so they have poor color performance but night? That is something to be discussed...

Trackerman
Posts: 85
Joined: 30 Oct 2017, 19:22
Location: ireland

Re: A Few Projects

Postby Trackerman » 04 Jan 2018, 12:27

lightmesser wrote:Hmmm...

It is really hard to pick... Some good cameras disappeared while EJ230 and E700 are very good all round performers especially for addon...

Wolf, Eagle and street lights. They will both be disturbed by them... Eagle sees little better(15-20%) Wolf is more complicated with a lot of settings, and crazy IR sensitivity so if you don't like to fiddle you will have greater white outs than on Eagle. It can be compensated in settings though.

Don't pick Wolf if you are not ready to modd it. Eagle is very expensive... E 700 is cheaper than Eagle...

So you see I can't give you right advice here. Maybe newest Yukon Photon with integrated DVR recording? I know you will be happy with it :lol:


When you say "Mod it" do you mean to remove the IR filter, I see from above thread it's hard to get off ?
I actually like to fiddle and gain small improvements where possible, so can the Wolf be adjusted via OSD to reduce the over-exposure from street lights?


And I like the idea of an IR Pass filter in front of the camera, in theory it should block lower frequency (visible) light and allow 850 NM light to pass, thus making the camera 'IR only' and reduce glare from street lights, something like this...
https://www.ebay.co.uk/itm/850nm-IR-Ban ... SwKrhVV5VD
It has a narrow pass band for 850NM.

According to the specs it looses 10% transmission at 850nm:
T_avg <1% 350-800nm
T =50% @ 828nm +/- 20nm
T_avg >90% @ 850nm +/- 20nm
T_avg <1% 880-1100

So one could try a camera lens type filter, attached to the scope, so it cab be removed if needed.
I suspect there will be times when the light pollution from visible light will swamp the CCD, so an IR-Pass filter will help even if it reduces IR by a small amount.
http://www.ebay.co.uk/itm/58mm-58-mm-85 ... SwRLZUIjFc

Worth testing out I think.

lightmesser
Posts: 468
Joined: 09 Jan 2014, 01:19
Location: Eastern Europe

Re: A Few Projects

Postby lightmesser » 04 Jan 2018, 13:13

Yes I agree that right IR filter in front of scope(addon) or in front of lens(scopless) will probably reduce overexposure of street lights or strong IR lights.

So yes I would also use them(have several 850 and even 720 at home but I still did not have need to put in front of camera sensor) but only at darkest nights with IR lights turned on. At right night conditions(moon, half moon, stars) I would want without that and without iluminator and filter cause it would probably significantly reduce that camera light gathering ability a lot?

But if we have situation with right night conditions which are messed up with street ambient lights which are overexposing sensor than why not give it a try?

Our member Lenny did it also this thread(pics are missing of course because of stupid photobucket) viewtopic.php?t=4443 and he recorded video with filter in front of of scopless lens: https://www.youtube.com/watch?v=LFPS4xDgRGU (start watch from 01:16 minute of video).

About Wolf once when you remove filter and put it on B/W mode special setting for adjusting of IR light will occur(sensitivity and area coverage) but you would also have to use image brightness option of Wolf(0-250 adjustment) so when you will set it darker it will kind a compensate IR light or street lights...

User avatar
MrNewbie
Posts: 286
Joined: 22 Dec 2012, 21:28
Location: Grafton, Ohio USA

Re: A Few Projects

Postby MrNewbie » 04 Jan 2018, 13:31

This makes it all neat and tidy


https://www.ebay.com/sch/i.html?_odkw=i ... h&_sacat=0


To recharge ... hook to any cell phone charger or computer

https://www.ebay.com/sch/i.html?_from=R ... d&_sacat=0

Trackerman
Posts: 85
Joined: 30 Oct 2017, 19:22
Location: ireland

Re: A Few Projects

Postby Trackerman » 04 Jan 2018, 13:56

Interesting video, thanks for sharing Lightmesser
I think a screw on IR-Pass (SLR camera type) might be the best option to test out for the reasons you outline above, I agree with them.
At least it's a good option to have depending on where I shoot.

Regarding the Wolf, I'm guessing the V2 is the one to get right? I can get it at 33 Euro which isn't a bad price.

and the point about it 'going black screen' until it sees enough light worries me a bit... can this function be turned off in the OSD?
Last edited by Trackerman on 04 Jan 2018, 14:27, edited 2 times in total.

Trackerman
Posts: 85
Joined: 30 Oct 2017, 19:22
Location: ireland

Re: A Few Projects

Postby Trackerman » 04 Jan 2018, 14:11

MrNewbie wrote:This makes it all neat and tidy


https://www.ebay.com/sch/i.html?_odkw=i ... h&_sacat=0


To recharge ... hook to any cell phone charger or computer

https://www.ebay.com/sch/i.html?_from=R ... d&_sacat=0



Thanks MrNewbie but arnt these Ir CUT filters and we need IR PASS...

Texan
Posts: 17
Joined: 30 Dec 2017, 22:49
Location: Texas

Re: A Few Projects

Postby Texan » 04 Jan 2018, 14:46

I agree that if you do not have significant visible light sources messing up your shot that an IR Pass would make things worse. I offered the suggestion only for situations where you have to deal with strong point sources of visible light. Like passing cars and street lights.


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