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Tacked DIY Cascade Tube Thread... (Page 17 of 17)
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Link Posted: 11/11/2017 1:06:34 PM EDT
[Last Edit: 11/11/2017 1:09:37 PM EDT by wattius]
Still waiting for that objective lens but i borrowed one from a camera for testing purposes. The aperture is way too high at F3,5-5,6 but it still sees better in the dark than naked eye.
It's not pretty but it works.

Video.

I also have to take back what i said before about it not making any noise because it does a little bit. i was not able to hear it when i tested the tube for the first time.
Link Posted: 11/12/2017 3:15:37 AM EDT
[Last Edit: 11/12/2017 3:28:14 AM EDT by hatti]
nice video!

seems like you get more distortion through a loupe eyepiece comparing to PVS-2 eyepiece.

to push cascade performance down to level of dark adapted eye you need to choke the lens down to f/10 or so,
thats according to my feeling.

loudness of whining is different from tube to tube, but newer ones usually are not loud.
worst one i had was an old early 80s p8079 (non HP) tube.

i have one tube with serial number over 20000 too, it does not make much noise.

where did you get the tube? starlightNV?
Link Posted: 11/12/2017 4:45:47 PM EDT
Thank you for the info.

Feels like the camera i'm using is amplifying the distortion. It's there and noticeable but not even close to how it looks like in the video. I'm now testing with a 50-200mm F4.0 zoom lens. Can zoom in pretty far but aperture is definitely an issue still.
Small clip with the zoom lens. Those buildings and lights are 2-4km away.

This is where i got my tube. They really shot up in price recently from what i've read.

A question or two, since you've had a few of these tubes from what i've gathered. How easy is it to cause damage to them with excessive light? I've pointed mine at some bright street lights very briefly while panning around and they leave a mark for up to 10 seconds before fading out. I believe that's not a big deal for as long as i'm not constantly pointing it at bright light sources. Also, have you noticed any degradation in performance on your tubes over time?

Will get back for at least one more post when i get the fast lens.
Link Posted: 11/14/2017 3:39:11 AM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By wattius:
Thank you for the info.

Feels like the camera i'm using is amplifying the distortion. It's there and noticeable but not even close to how it looks like in the video. I'm now testing with a 50-200mm F4.0 zoom lens. Can zoom in pretty far but aperture is definitely an issue still.
Small clip with the zoom lens. Those buildings and lights are 2-4km away.

This is where i got my tube. They really shot up in price recently from what i've read.

A question or two, since you've had a few of these tubes from what i've gathered. How easy is it to cause damage to them with excessive light? I've pointed mine at some bright street lights very briefly while panning around and they leave a mark for up to 10 seconds before fading out. I believe that's not a big deal for as long as i'm not constantly pointing it at bright light sources. Also, have you noticed any degradation in performance on your tubes over time?

Will get back for at least one more post when i get the fast lens.
View Quote
cannot really answer about tube damaging, because probably i am too careful with NODs, unfortunately,
but these trails from bright sources are nothing to worry about.

i live in unpopulated area, where there is no artificial light sources and even no sky glow, so my chances to damage a tube are small.
only once i got tube overloaded with light and built in emergency shutdown triggered.

one thing i would like to warn about is incandescent lamps - car headlights and especially these 500 watt PIR sensor activated floodlights.

have not noticed any signs of tube degradation yet.
i am reluctant to use NODs fully open in full moon conditions, dusk and dawn and in those midsummer "white nights" though.

i guess tube degradation is gradual process and it is very hard no notice without side by side comparison to some reference tube.
Link Posted: 11/15/2017 10:38:19 PM EDT
Thanks again.

Got the faster objective fitted today. Spent 2 hours testing it in the darkness and it's working really well so far.

This is the sort of image i'm getting during the darkest time.



A bit out of focus. Snow is providing a lot of illumination but i still could only see halfway down the road and the treeline, that's about it. The thing is really turning night into day.

The box is attached with some velcro tape for now at least. It wobbles a bit but it's not going anywhere.


Real-time voltage monitoring.


Inside the box.
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