best camera for all sky use

[Horwig]

I'll start a new thread rather than hijack Gina's. Now that I've killed off my trusty QHY5, I'm on the prowl for a replacement.

I've tried my Lodestar, and it was excellent, but what else is out there with the sensitivity and low noise of the lodestar, but with a bit more resolution?

Been looking at the QHY5 II range, confused, has anybody done a real comparison between them?

What else is out there?

Huw

[Gina]

I like the look of the ZWO ASI 120 series.  I'm planning to get an ASI 120 MM for nighttime imaging when I have the funds.

Sensor: 1/3" CMOS AR0130CS(Color) / MT9M034(mono)
Resolution: 1.2Mega Pixels 1280x960
Pixel Size: 3.75µm
Exposure Rage: 64µs-1000s

QHY5 resolution is 1280x1024 - a bit better.  Sensor is 1/2" CMOS so pixel size is slightly bigger.  OTOH the ZWO cameras are more recent and more sensitive.

[Horwig]

Thanks Gina, I think that camera uses the same sensor as the QHY 5L II, which is what tdnicholls uses in his:

http://stargazerslounge.com/topic/240630-another-diy-all-sky-camera/

reason I wanted higher resolution is that the lodestar is binned x2 by PHD, which makes it very small. However, have just now discovered LodestarLive, nice piece of software, reads full rez data from the lodestar, and can be rescaled on screen. Tried it indoors, will give it a go under the stars tonight.

Can I stretch to another Lodesar, and if I do would it be Lodestar 2 Colour?

How much are Kidneys worth these days?

Huw

[tdnicholls]

HI Huw,

As you see I now use the QHY5L-II M though the original test unit was a QHY5-II, main difference between the two is sensitivity but the drivers also differ and you have less resolution options with the QHY5L-II.

The choice I guess depends a lot on what you want it for, my main driver was to check for cloud as part of the remote observatory build. To that end the quality and sensitivity is perfect for me.

The software set-up was also pretty easy, EZPlantery makes a fairly good punt at auto exposure and Live Broadcast driver allows me to feed the output to my main CCTV software so easy to check via my phone.

Not sure why you you ever want to use a lodestar as an allsky camera, lots of pennies  - I would be looking at the Millincam commercial unit before then ( http://www.khanscope.com/productdetails.cfm?productID=5630) about £180 before shipping and taxes.

[Horwig]

HI Huw,

As you see I now use the QHY5L-II M though the original test unit was a QHY5-II, main difference between the two is sensitivity but the drivers also differ and you have less resolution options with the QHY5L-II.

Ah, I'd forgotten that you had both versions of the qhy, what would you say was the difference in sensitivity/signal to noise between the II and the L-ii, and have you tried the colour L-ii?

Huw

[tdnicholls]

Better on both counts, not tried the colour though I do have one - not really should why colour is required though ?

For comparison here are are a couple of videos

This is from the QHY5-II

https://www.dropbox.com/s/dxzeoielkpnbamk/AS18Feb.mp4?dl=0

And this from last night on the QHY5L-II (would give in till 7:45 today(6th April) to upload fully

https://dl.dropboxusercontent.com/u/10508371/QHY5L-II-AllSky.mp4

[Horwig]

IT WAS CLEAR, WITH NO MOON

Pardon my excitement, but it's been rare this year.

Anyway. Here's the Lodester (Mk 1), with the Fujinon f1.4 lens as before. 1 minute esposures, at 22:30 tonight, fairly pleased, agree with Gina about not being easy to focus.

Used lodestarlive, very nice, but did the eventual capture in Maxim, cos I knew how it worked.

[tdnicholls]

Like that Huw - darker skies than me it looks like, if tried 60s here it would blow out.

The lodestar is head and shoulders above the QHY as far as sensitivity goes, replaced the QHY with a lodestar as as the guide camera hence having in the QHY to play allsky with.

[pete_l]

What else is out there?

Have you looked at the LN300? It's a 640x480 vid cam with an Exview sensor and onboard integration of up to 20 seconds.

You will need to buy a fisheye lens, power+cable and a video cable and a video capture card which ups the cost (the camera itself is < £50 shipped free from China). I have 2 of these and they are excellent. Extremely sensitive, solidly built, physically small and easy to use.

The ones I have are model number MC-300-11673 not to be confused with the other variants out there.

[Gina]

Like that Huw - darker skies than me it looks like, if tried 60s here it would blow out.

The lodestar is head and shoulders above the QHY as far as sensitivity goes, replaced the QHY with a lodestar as as the guide camera hence having in the QHY to play allsky with.

Yes, I too replaced my QHY5 with the LodeStar for guiding and later upgraded that to the LodeStar X2 which is even more sensitive and useful for imaging I'm told.  Same resolution as the original though.

[Horwig]

Not sure why you you ever want to use a lodestar as an allsky camera, lots of pennies  

Actually, I bought an used lodestar to go with my QSI for the same money as a QHY5L

H

That should read QHY5L-II

[Gina]

Which software did you use with the LodeStar, Huw?

OOOPS Didn't read your post properly - you said

[Horwig]

I've had a go at using Lodestar Live, very nice software, primarily it's a video astronomy package, but useful as a monitor for the Lodestar. It could do with an auto stretch function etc, but the ability to resize the window, which zooms the image is nice. Download from here:

http://stargazerslounge.com/topic/234260-lodestar-live-v011-beta/

Wonder if the developer would be interested in tweaking it for all sky viewing?

H

[Gina]

Thank you Huw - I'll check that out   That image looks pretty good   Though I don't think I'll be changing cameras any day soon depending on whether I can cure or cater for the gradient I'm now getting with my QHY5.

[keithatrochdale]

A fried of mine has been experimenting with all sky cams for a while, maybe worth a look at his site;

http://www.amastro-uk.com/meteor.html

[Horwig]

Ho hum, at this point I've been looking at published specs.

Starlight Oculus uses the same chip as their Superstar, the Sony ICX205AL, so lets put that in the mix:

Lodestar (original), Read Noise 10e, gain 0.9e/ADU, QE 65% resolution 0.44 Megapixel

Lodestar (mark 2),  Read Noise 6e , gain 0.4e/ADU, QE 77% resolution 0.44 Megapixel

Superstar,            ,  Read Noise 7e , gain 0.3e/ADU, QE 50% resolution 1.45 Megapixel

QHY5L-II,             ,  Read Noise 6e , gain ??           , QE 74% resolution 1.23 Megapixel

Correct me if I'm wrong, but we could do a comparison on signal to noise ratios, assuming short exposures, so insignificant dark noise.

Lets call the photon count 10,000 for the sake of argument, but its just an arbitrary figure, I'm not taking well capacity into consideration, and I'm assuming that the stars are so small they only illuminate one pixel each.

Noise looks like this I think:

Lodestar (original) 56dB

Lodestar (mark 2) 62dB

Superstar,             57dB

QHY5L-ii,              62dB

As absolute figures, these mean nothing, but as a comparison, it does show the mk2 Lodestar as 6dB up on the original, which is what they and Sony claim for that chip, so the other figures may be close.

Please pick holes in the argument, I'm not claiming any great mathematical prowess here.

Huw

[Gina]

Great stuff Huw - thank you   Maybe a rough price comparison should be added too   I can contribute that

Taking your figures and ignoring price, the QHY5L-II semms to come out on top with low read noise, high QE and a good resolution.

[Gina]

Lodestar             £345 - FLO
Lodestar X2        £449 - FLO
Superstar            £465 - FLO
QHY5L-II Mono   £229 - Modern Astronomy

[Horwig]

Yes indeed the qhy is half the price of the Superstar and Lodestar mk2, I wonder what Trevor (tdnicholls) has to say, as someone who owns a 5L-ii and a Lodestar.

QHY only publish minimal data on their cameras, no gain, and no data on the colour version.

SX publish dark noise figures for the original Lodestar and Superstar, showing 0.1 e/second for both. I'm assuming the Lodestar mk2 to be similar, so exposures up to a minute or so should not show great increase in noise.

Huw

[Horwig]

Found the manufacturers data on the MT9M034 chip from the QHY5L-ii, used in both the mono and colour versions, QE quoted at 74% mono, 62% colour, (green), so not too bad in colour, and 45 quid cheaper in colour than mono.

H

[Gina]

I quoted the mono price as I thought more suitable for ASC for night-time.  I was rather surprised.

I think we should add the ZWO cameras - ASI 120MM £232.80  from 365 Astronomy.  Been trying to find data without much success 1.2 Mpx 1280x900 64us-100s exposure QE - 75% in green falling to 50% at Ha wavelengths.  I can't find the read noise figure.  Does come with 150 degree wide angle lens included in price FWIW

Later... found it uses the same image sensor as the QHY5L.  So effectively you get a wide angle lens for £3.80 extra with the ZWO

[Horwig]

The Mono ZWO uses the AR0130cs chip, QE 78% mono, Colour 68% green, 64% red, not at all bad, Mono camera uses the same chip as the QHY5L-ii. And again, colour is cheaper than mono, £224.80 as opposed to £232.80.

H

[tdnicholls]

To be honest I have not done a comparison between the Lodestar X2 and the QHY5L-II. I used to use the QHY5-II as my guide can but changed to  the Lodestar X2 when started to use an OAG on my edge as had real difficulty finding guide stars, the lodestar X2 was a massive leap forward over the QHY5-II.

When I first built my Allsky I used the QHY5-II and later moved to the QHY5L-II, again there was a marked improvement in pixel gathering and noise control ability's.

Of the two the lodestar X2 has the edge, far more stars in that image you posted Huw than I get,  but not by huge amounts and for Allsky camera use I am not if the benefit would be worth the cost.

The reason I built the Allsky was part of my obs remote automation project, more to act a quick visual check as to the conditions before hitting the button to open up the obs and for this task the QHY5L-II is perfect and the premium pack includes a 180deg lens making it a one stop purchase.

So best camera for Allsky use - really need to define what the use is, cloud check, meteor or high quality allsky photos, is software a consideration, availability of lens etc - lot more factors than just sensor performance.

[JamesF]

Modern Astronomy are knocking out the QHY5L-IIc for filthy cheap on ebay every so often.  No idea why and they don't appear to match the price on the website, but on ebay occasionally they get offered for £144 by the looks of it and there's nothing to indicate that it isn't a brand spanking new camera as far as I can see.

James

[Horwig]

Thanks James, just pressed the buy button, £149 delivered, guess it's a steal, lets see how it performs.

Huw