About to order a QHY5L-II mono, help me confirm cam and filter

[Jannis]

So, i'm about to order a new cam to mainly replace my unmodded SPC880 as a guide-cam through the finder scope on my explorer 200 PSD.

I'm also planning to use this for sonme planetary and moon, wich i guess it should be well suited for?

Also, i'm thinking about combining it with an IR filter (Astronomik IR Pro (742nm)) to capture some deep sky IR data to add to my none-modded DSLR using the 200mm finder-scope. Would this cam be able to do this as well?

I know it's not an ideal option as it's neither a cooled CCD, nor the correct focal lenghts for combining the two, but i'm hoping it's better then no IR data at all.

[Scott]

watching this with interest...sorry I can't help

[Jannis]

I'm pretty much 99% sure allready though, and if noone comes with a better option, i'll order it in a coupple of days when Bernard have made the shipping list and price quote for me.

I'm unsure if this is the correct filter to use to capture the IR data my unmodded DSLR won't though? It seems to be blocking for example Ha as well, or have the strong sun just boiled my head now?

I'ts posts like these, pluss information from Bernard that's made me come to a 99% conclusion. As finding any comparisons and tests of the 5L-II online is surpricingly rather difficult.

I have both the QHY5 & QHY5L II and IMHO the QHY5L II is way ahead of the QHY5 in both specification and quality of the images.

For one the QHY5L II is a planetary & basic DSO camera and a good sensitive, crisp and clean image guider, no banding issues whatsoever.

The QHY5 is a guide camera which can suffer from image quality and banding.

cheers

Steve

The spec flyer looks OK from what i can see, but i honestly only understand like 80% of it. But it seems the sensitivity needed is there, both for guiding on very faint stars, as well as capturing some Ha data?

http://qhyccd.com/en...qhy5-ii-series/

A bit unsure how i'll be guiding when imaging with the guiding camera though, but i'll hopefully find a way.

Complete shopping list:

229£ QHY5L-II Mono

39£ QHY5-II / QHY5L-II Adapter for Straight Through Finders

39£ Deluxe Laser collimator 1.25" (includes batteries)

139£ Baader MPCC MKIII Photo

34£ Astronomik Pro IR 742

20£ Vixen Style Photo Dovetail

500£ total

Hope my wife won't kill me for spending £500 on this though... ^^;

[Jannis]

I have to admit the filter Does sown awsome though, but i'm a but unsure if it's what i need.

It seems to cut off everything below 742nm, including Ha.

I can see a good advantage of it though: "Another advantage is that the sky background of advanced dawn is dark and so the filter even allows photography of the planets and the moon at daylight."

However, the 5L-II is only having a QE of like 35 at ~750nm, and dropping fast aftwerwards. Is the filter going to be possible to use at akll with this camera?

And should i also/instead go for a spesific Ha filter or other filter?

[Jannis]

After looking at the different filters, it's obvious, yes: the sun have indeed boiled my head well, lol.

I'm obviously going to need a Ha filter, for wich the 5L-II is absolutely sensitive enough with about 53 QE or so.

But reading up on the 742 filter i'm getting quite interested in that too actually.

Would the Baader 35nm Ha or the Astronomik 12nm Ha filter be the best choise?

[Shibby]

Hi Jannis,

I'm not that knowledgeable on this but IR filters + cameras such as the QHY5 are often used for imaging bright objects such as the moon & planets.

For DSOs, an Ha filter can be used to enhance existing colour DSLR images... I use one on my DSLR to this effect. The problem with IR is that the atmosphere blocks out virtually all of it, so very little IR DSO imaging is done by amateurs because of the low brightness involved. This is why the best IR observatories are on the highest mountains, in space, or flying around in a plane! (Look up SOFIA).

You can't use the same camera to guide and image at the same time.

The 35nm Baader filter is specifically for very fast optical systems such as hyperstar. the 7nm Baader is a good choice for an f/5 scope such as yours. Bear in mind that the FOV on the QHY5 is much smaller than that of your DSLR, so you may be better off using the DSLR for Ha, as I do, in which case you'd really want the 2" (or EOS Clip) version.

Hop some of this helps!

[Jannis]

Thanks for the reply. I think i'll have a 7nm or 12nm Ha filter at a later time then. I'm a bit curious to IR, so i think i'll have a go for that first, just for fun. It's also a very inexpencive filter, so.

I know i won't be able to guide with the qhy5 at the same time as capturing with it, however, i have a very different and probably unusual thought in mind.

I'm going to use the finderscope to capture the IR/Ha data, as it's very close to the 550D's FOV on the explorer 200. That means i'll have the 550D and main scope free, so i'm going to have a try at this:

connect the 550D to the main scope, boost the ISO and exposure in live-view to find a solid guide-star. use 100% zoom on a separate display only for the 550D's live-view. Then firmly mount the SPS900 cam close to the display, and attempt to guide on the display throught the 550D's live-view rather then using the SPS900 directly (as it's not nearly sensitive enough to be used directly on the main F/5 scope unmodded at least).

Maybe tro to slightly de-focus the main scope to spread the guide-star onto a few pixels to increase the guiding performance.

Although it will be far from perfect, i'm hoping it will work better then no guiding at all.

Alternatively, i'll just the the SPC900 as it is now, with the 135mm F/3,5 lens currently attached to it, and use that for guiding, but i've been struggeling to find a solid guide star like this though...

Still, mostly i'm curious if the QHY5L-II is even capable of deep sky imaging at all compared to the DSLR, but i guess time will tell.

Edit: note my 550D is not modded, so it's very insensitive to Ha, that's why i'm hoping the 5L-II will give better result for Ha, and use the 550D for RGB.

[Daddystu]

Still, mostly i'm curious if the QHY5L-II is even capable of deep sky imaging at all compared to the DSLR, but i guess time will tell.

I was actually surprised to find a rather good image of M57 through my QHY5 mono whilst selecting a guidestar. I quickly switched to sharpcap to grab a quick avi but it didn't come out so well unfortunately.

[Shibby]

An interesting idea indeed! I suppose there's no reason you can't image through the guidescope as long as you are using a narrow-pass filter, otherwise you'll surely get nasty aberrations.

I guide with an SPC900 and find it works perfectly well; it is also much more sensitive than the liveview on my 450D. I don't know if that applies to the 500d or not...

Are you concerned that the small FOV? Is that why you're thinking of using the DSLR? If you can't find a guide star with the webcam, you could always try unguided - you should be able to expose for reasonably long at the short focal length of a guidescope.

[Jannis]

I'm concerned about the FOV for guiding, yes. Concidering i struggle to find a guide star with teh webcam with a 135mm f 3-5 lend, it's a dead run to even try at 1000mm f 5.

The 550D sensor sensitivity isn't a problem, as i can set the live-view exposure up to several sec if needed with magic lantern. I have no problem seeing several DSO's in the live-view - so finding a guide-star isn't going to be an issue.

I haven't had much luck with my mount unguided. Even 30s exposures have more often then not been a mess. >_< Guiding graph in PHD looks smooth most of the time though, so i don't know why it's so bad unguided.

I'm planning on using the 550D on the 1000mm scope, and the QHY5L-II on the 200mm finderscope. Calculating the sensor size and focal lenght, the FOV isn't really that much different between these two now.

So in theory now, i shuold, with some resizing, be able to combine the Ha (and maybe IR, if that's possible at all) data taken through the 200mm finder-scope, with the RGB data from the 550D taken through the 1000mm scope.