DIY all-sky cam?

[Gina]

I think it might be possible to block the stray light by having the shutter/filter sliding over flocking material.  I have replaced the foam pad surround for the sensor that kept out stray light originally and temporarily attached a small square of solar film to that with Sellotape.  Result is no stray light

[Gina]

Made a shutter with solar film attached.  It works

[JamesF]

Those images are shot through solar film, Gina?  I'm amazed it's possible to see so much detail.  I wasn't expecting anywhere near as much as that.

James

[Gina]

Those images are shot through solar film, Gina?  I'm amazed it's possible to see so much detail.  I wasn't expecting anywhere near as much as that.

James

Oh yes   Here is a photo of the shutter in daytime position as was used for the image above.  The silvery stuff is the solar film - a corner from what was left from my MN190 solar filter, hence the funny shape.  It's temporarily held on with Sellotape.  Following is a screenshot of the model of the shutter.

[JamesF]

That's quite impressive given that when I look through solar film to check for faults in the film I can't see anything at all through it.  Is it the ND5 (visual) film, or the photographic-only one?

James

[Gina]

That's quite impressive given that when I look through solar film to check for faults in the film I can't see anything at all through it.  Is it the ND5 (visual) film, or the photographic-only one?

James

ND5.  I think an astro camera is more sensitive than the human eye at 0.2s exposure

[Davey-T]

Shades

Is that not a good idea, a lens from sunglasses that darkens itself ? can't remember what they're called. old age is a bu'er.

Dave

[Gina]

Is that not a good idea, a lens from sunglasses that darkens itself ? can't remember what they're called. old age is a bu'er.

Dave

Photochromic is the word.  But we need more than that.  Might help with daylight image though - I was envisaging some form of automatic exposure control.

[Davey-T]

Need some sort of failsafe though I guess so it failed into the closed position.

Dave

[JamesF]

Photochromic is the word.  But we need more than that.  Might help with daylight image though - I was envisaging some form of automatic exposure control.

I did wonder about a filter along those lines, but I'm not at all convinced it would reject sufficient light from the Sun to prevent damage to the sensor.  I think the solar film is a safer bet.  I'd hazard a guess that easily available photochromic lenses don't cut much more than 50% of the available light.  ND5 film allows only 0.00001% of the light through (and ND3.8 something like 0.00016%) which is an enormous difference.

James

[Gina]

Quite so!

[Gina]

Since there's cloud forecast for tonight I'm not imaging with a telescope so the laptop is available for all sky cam use.  I have it set up on a board outside with the camera perched on an empty filament spool pointing up at the sky.  I've adjusted the focal length so that the image fits the sensor area and roughly adjusted focus.  Exposure is 15s in PHD2.  Guess I should say that the shutter is open - no ND5 solar filter.

This is just a screenshot from my desktop connecting to the laptop with TeamViewer.  No image processing has been applied whatsoever.

[garethmob]

is that a wisp of the milky way gina?

[JamesF]

Nice view of the Summer Triangle there, Gina.  I suspect you might even have caught M31 at the top.

James

[JamesF]

is that a wisp of the milky way gina?

Definitely so.

James

[Gina]

is that a wisp of the milky way gina?

Yes, I think so

[Gina]

Nice view of the Summer Triangle there, Gina.  I suspect you might even have caught M31 at the top.

James

Could be

[JamesF]

Actually, I reject my identification of M31.  I think it ought to be behind the tree at 12 o'clock.  I'm not at all sure what the white smudge slightly to the right of the tree is.  Could just be a cloud, even.

James

[Gina]

Here's that single screenshot image processed in Photoshop to dig a bit more out.

[Gina]

Been out and fiddled with the lens controls and I think I've got it a bit better.  Getting to the point of needing darks - must take some   I have the ASCOM camera gain set at 75% so I guess I could take that up to 100%.

[JamesF]

What I initially thought was M31 is definitely something transient then.  That looks like Cassiopeia at the top at about half past twelve, with UMa at 3 o'clock.  The Milky Way has came out rather nicely in the last one.

James

[Horwig]

Hmmm, those pics are much cleaner than the ones I've been having Gina, where do you have the screen gamma control in PHD? And those are without darks?

[Gina]

Thank you James and Huw   I think the slider was about a third of the way from the left.  I'll check later, I think it keeps the settings.  Must say, the results are better than I expected

I'm now designing and printing case parts to hold the dark box and shutter motor etc.

[Horwig]

Ok, this is a start on the shutter, it might even work!

Meter arrived this morning, all of £4.37, and was stripped down to the movement. I've cut back the camera pcb in an attempt to make everything fit the case.

Off projects for a while now, going away with work.

Huw

[Gina]

Have a good away trip Huw   Your shutter system looks good - I'll be interested in the results

My system is much beefier and takes up a lot more room but I have the benefit of a 3D printer so can make up whatever I like   Wasn't cheap though