Another DIY All-Sky Camera

[tdnicholls]

HI,

Seen a few threads on this recently so thought I would post my version, did look at what is available in the market and though some nice units the cost can be prohibitive.

So the DIY route, I had a spare QHY5-II mono that had been sitting in a box since the lodestar replaced it and I also had the premium pack from QHY giving me a 150deg fish-eye lens,.

I did see all the talk about the possible impact of the sun on the sensor and totally disregarded it, commercial units don't seem to have such protection, also the QHY has a temperamental USB socket so would be know great loss.

The search began for a housing/dome, there are a few on ebay, damn cheap at £6 but also very poor quality, as I had never been able to get focus with the fisheye I did some investigation and figured my CS adapter was too big at 10mm, quick call to Bern at Modern Astronomy sorted that out and during the conversation he mentioned he had a spare dome from previous investigations, cut a long story short I got one these - not the cheapest dome but really good quality.

Some wandering round B&Q and some tinkering in the garage and this emerged

Summary of the build, no pictures of the actual build process but is pretty simple.

Parts and construction (bits from B&Q)

Floplast Black Adaptor (Dia)110mm (L)150mm

Floplast Black Access Cap (Dia)110mm (L)360mm

Floplast Black Pipe Clip (Dia)110mm (L)849mm

PVC Pipe Weld and Self-Amalgamating rubber tape

1. (Adapter)Prise the sealing ring of the wide part of this, this gets you a plastic ring (throw away) and a rubber sealing ring, this fits just nicely over the base of the dome and fits inside this adapter, does seal it but not a strong connection and I have wrapped some Self-Amalgamating rubber tape around the join.

2. (Access Cap) 2 of the above are used, the one that holds the camera fits inside the first adapter, have to open out the inner flange of the first adapter so this just sits inside and is glued in place with pipe weld, there is a 2nd cap under the screw lid and this is not used here. A 32mm hole is drilled in the centre of the cap to hold the camera which is help in place by two parafocal rings.

There is a gap formed between the adapter and access cap, I have placed a dew strap for a 5” scope into this cap and drilled a series of 2mm holds around the flange of the adapter to allow airflow, should provide gentle air flow around the inside of the dome, not tested how effective this will be yet.

The 2nd Access cap fits into the bottom of the adapter, a 2” hold is drilled in the cap, the blanking plate is retained and a 2.1mm DC socket fitted and the dew scrap cable cut to length and soldered on, this is the 12v feed.

I had to drill a 12mm hole to fit the USB adapter to and have not done anything to fill the gap left, this will let out water if any does get inside and should help with the airflow.

The pipe clip is fitted to the bottom access cap and the whole lot pushed together.

Interesting little project, lot cheaper if somewhat large than the commercial equivalents.

Since I built this one the original QHYs USB gave up completely and as the what sun was around had not caused any issues I got a QHY5L-II mono, lot more sensitive.

There have been some design changes based on the results of the last couple of weeks. One problem was that the inside of the dome would mist up due to damp air getting in via the ventilation holes in the flange. I have now fully sealed the camera chamber and included some desiccant to ensure this is a dry as possible. 

Heating is still provided via the dew strap but the hot side now faces outwards and provides enough heat to prevent the dome from dewing.

I have added a small 30mm fan to the underside mainly to stop moist air build-up in the central chamber and pull away excess heat generated but the camera, it gets fairly warm running continuously.

Have it running continually along side my cloud sensor, temp location till the obs is completed. 

From a software point of view I discovered that EZPlantery (v3.7.7) is capable of doing auto exposure via the histogram tool, has 3 buttons ACE, AGE and one initially marked AVE. The first two are Auto Exposure and Gain and the 3rd seems to define the mode used, this has 3 settings AVE, () and . there is zero documentation bit of a guess as to what mode does.

AVE is just an average over the whole frame, not a good mode for an Allsky due to the dark around the fisheye image and this results in blowing out the whole image.

The () mode seems to try and keep the histogram at the level you have manually set and this works well.

Not sure what the . mode is, maybe spot but results in a lot of image adjustment so I am currently using () and this seems to work well.

Another plus point for EZPlantery is the live broadcast mode using the WDM driver, I have a number of CCTV cameras keeping an eye on things here and use some software called Blue Iris to manage, record and motion detect on these. Using live broadcast mode I am able to feed the Allsky into this software.

This allow me to access the feed from a web browser and on my phone and also record continuously if I want, useful if want to feed the nights output into one of the meteor detection programs.

Blue Iris also allows you to add overlays, I have just added compass points, time and location and allows me to access via a web browser.

Most of this has come together now and have it working pretty much as I want, I have seen no issues relating to sun damage but yet to get to the long summer days so time will tell on that one.

Next stage is to mount it into is finial position but that will have to wait till the observatory is completed.

Cheers

[julianr]

That is looking good - interesting project

[Cath]

Cool

Be good to see a days time lapse recording from it

[tdnicholls]

Cool

Be good to see a days time lapse recording from it

This was from the original camera, hopfully the link will work.

I record continuously these days at 15 FPS - will look at taking every 60th frame or so out of one one of those recordings. 

<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid1345.photobucket.com%2Falbums%2Fp672%2Ftdnicholls%2FAstronomy%2520DIY%2FAllSkyCam%2FAS18Feb_zpsou9p2tcw.mp4&title=">

[tdnicholls]

Cool

Be good to see a days time lapse recording from it

This is a better video, 8hrs compresses into 3.44s for 16:00 to midnight lastnight

https://www.dropbox.com/s/xe65mbek1vs5gpz/AllSkyVid1.mp4?dl=0

[Astronigel]

I see this being a nice little future project for me.

[jaspalchadha]

Super

Sent from my iPhone using Tapatalk

[aruangra]

Many thanks for sharing your idea. I follow your idea  I also run Skychart (CdC) in parallel and show a live skychart. Blue Iris for iOS is very handy to show both allsky and skychart image. 

I still struggle with setting proper values in EZplanetary. Could you tell me your values of 

- gain

- exposure (there are ranges to choose (us, ms, s). It seems that AEC won't switch across the preset range. So It is difficult to make the camera works for both daytime and  nighttime.

- gamma? 

Do you enable AGC ? 

Thank you.

Anat

[tdnicholls]

Hi Anat,

I enable both AEC and AEG and set the AVG button to () as the screenshot below and this does switch across ranges ok but does not always change the text indicating that.

The gain I have set to .9 currently and the exposure and gain are handled by the histogram. Which version of EXPlantery are you using, I have found the best version V3.7.7, they removed AEC/AGC from later versions.

What version of the QHY driver are you using, as well I have V1.0.0.0 dated 12/12/2014

Thnaks

[aruangra]

Thank you. I use EZpanetary 3.7.8. So I will try the former version. I also use the high compatibility driver (Ver. 14-12-12).

Best regards,

Anat

[aruangra]

BTW, do you use QHY5-ii or QHY5L-ii ?  

Anat

[tdnicholls]

Now using a QHY5L-II Mono, I did start with the QHY5-II mono but has a duff USB connector.

[aruangra]

It works. It takes about 10-15 mins in EZplanetary to lower exposure times in early morning from an oversaturation state. I wasn't patient enough previously

I found mask files inside C:\Program Files (x86)\QHYCCD\EZPlanetary\EZPlanetary\LUTMAP

It may be possible to change the coverage area for auto exposure

Best regards,

Anat