Hi Duncan,
I've just added to my website a brief description on how I captured flats for the QHY8 using MaximDL. It seemed to work well for me. Perhaps it could help. http://www.astroromp.com/astronomy/s...lat_frames.htm
I'll try and work on a more comprehensive description in the coming days that covers how I processed the images using calibration frames.
Matt
Hi Duncan,
I've just added to my website a brief description on how I captured flats for the QHY8 using MaximDL. It seemed to work well for me. Perhaps it could help. http://www.astroromp.com/astronomy/s...lat_frames.htm
I'll try and work on a more comprehensive description in the coming days that covers how I processed the images using calibration frames.
Matt
Matt, you've been an absolute saint through this, and i think your work is done !!
thanks heaps mate, its appreciated
PS. after i got back, i had terrible sunburn on my head and arms ...
How's it going Duncan? Still tearing your hair out?
Or are you getting a handle on it.
Hey Dave, thanks for your concern! still tearing my hair out. There are a few things that throw me, namely the terms used, and the procedure. i have taken a few pics, but TBH, i cant see much difference between the QHY8 and my Canon, i got the CCD for two reasons, cooling with longer subs, and a great colour bit depth, although i am yet to see this in my images, but thats no reflaction on the equipment, merely me being a n00b.
I almost gave up imaging with the Canon, as i found that difficult, although i got there in the end, i am sure i will get there with this to, although the learnign curve is VERY steep.
do you know, do you have to keep the IR nosepiece on? or can you put anything you want on there? i took it off, and just used a camera adapter, with the MPCC attached.
do you know, do you have to keep the IR nosepiece on? or can you put anything you want on there? i took it off, and just used a camera adapter, with the MPCC attached.
Got to be careful if you remove the nose piece. The camera will ice-up real quick if there is moist air inside. I currently use a MPCC with the nosepiece glass off but I blow dry the air in the camera and adapter prior to assemble. It works fine for me.
Got to be careful if you remove the nose piece. The camera will ice-up real quick if there is moist air inside. I currently use a MPCC with the nosepiece glass off but I blow dry the air in the camera and adapter prior to assemble. It works fine for me.
Thanks for that Marc. i was putting the CCD and MPCC in a clear plastic bag, filling the bag with warm air from a hairdryer, and throwing a few bags of silica gel in there, and then assembling the whole lot, with the bag tied shut
i was putting the CCD and MPCC in a clear plastic bag, filling the bag with warm air from a hairdryer, and throwing a few bags of silica gel in there, and then assembling the whole lot, with the bag tied shut
That'll work nicely although you don't have to go to that extreme unless you do this outdors, then yes the bag trick is good.
I usually assemble indoors. Hold the camera without the nose piece face down then blow air up in it (warm - not hot). Do the same for the spacer and MPCC in the cavity then quickly assemble them.
One thing I did too was to tape all around the body of the QHY8 with black electrical tape to "seal" it. Both from light leaks and air. Also siliconed around the power/USB plugs. I also recently got some silica gel strips from Theo to stick on the walls of the spacer but I haven't had any problem so I didn't use them as yet.
One thing to keep in mind is the orientation of your camera too. If it points down the cold air will fall on to any glass surface at some point and you will fog up. So just look for that when you choose your target to image or side of the meridian.
Learnt that the hard way when shooting flats with my 67mm pentax lens and I sat the QHY8 face down on my EL sheet First two 0.5s flats were fine. Took less than a second to fogup the lens.
Marc, how do you attach the MPCC? i think i have my spacing correct with the rings etc, but i cant be sure.
i am pretty certain its sitting at 55mm away from the CCD, although i have to remove the IR Nosepiece to do this.
Ha... that's another one I got stuck on for months. I ended up getting a custom spacer done from http://www.tan14.com/gears.htm. On my 5" newt I need 53.5mm. On the ED80 closer to 56mm. So I have a telescopic adapter that gives me nearl20mm travel on each side. I posted a pic to this reply.
The nose piece is approx 13mm, the sensor plane is approx 6mm from the outside face of the camera so you already have 19mm there minus 55mm that gives you approx 36mm for the spacer on top of the nose piece.
You will find that keeping the nose piece with the MPCC gives you terrible results on bright stars. Light bounces like crazy and you get secondary reflections everywhere.
Ha... that's another one I got stuck on for months. I ended up getting a custom spacer done from http://www.tan14.com/gears.htm. On my 5" newt I need 53.5mm. On the ED80 closer to 56mm. So I have a telescopic adapter that gives me nearl20mm travel on each side. I posted a pic to this reply.
The nose piece is approx 13mm, the sensor plane is approx 6mm from the outside face of the camera so you already have 19mm there minus 55mm that gives you approx 36mm for the spacer on top of the nose piece.
You will find that keeping the nose piece with the MPCC gives you terrible results on bright stars. Light bounces like crazy and you get secondary reflections everywhere.
Do you mind explaining how you arrived at the figures mentioned - 53.5 and 56 mm? Is it just trial and error or is there a formula?
Also, with the adjudtment rings, did you buy them as a set from Peter Tan or did he have them made up to your design and specifications? Obviously, the idea strikes me as a good one - using the final threaded adjuster with the little lock ring. If someone isn't making this as a set they probably should.
Peter.
Do you mind explaining how you arrived at the figures mentioned - 53.5 and 56 mm? Is it just trial and error or is there a formula?
Yes Peter, trial and error. I took pictures of Alpha Crux centered on the CCD chip and run the subs through CCD Inspector measuring the spacer with an digital caliper.
Quote:
Originally Posted by pmrid
Also, with the adjudtment rings, did you buy them as a set from Peter Tan or did he have them made up to your design and specifications? Obviously, the idea strikes me as a good one - using the final threaded adjuster with the little lock ring. If someone isn't making this as a set they probably should.
Peter.
I originally bought the solid spacer he sells for the QHY8, But I couldn't shorten it. I did some test by moving the spacer away and I was over correcting so I figured I had to shorten the distance and in order to do that I needed a shorter spacer. I wasn't ready to stuff around with different lengths rings so I worked out this spacer and send him the drawing see if he could do it and it worked a treat.
I googled all over the place for one and nobody made any. I was really surprised because to me it's just common sense to have an adjustable spacer for field flateners or coma correctors rather than fixed length rings.
I couldn't find it in here, but did I read some where about reflections pertaining to the filter glass in the noise piece of the QHY8? If I want to do RGB with the camera, do I need to use the UV/IR glass or can I take it out and just use the extension on the front of the nose piece with out the UV/IR glass and the MPCC? If I'm using a reflector, how does this affect my images in respect to star bloat/bleeding, UV or IR saturation? I have a 1.25 inch filter wheel that I'm gonna use(loss of field, vignetting, etc all understood already) with Ha, OIII & SII filters, so I don't need UV/IR for those, do I? Would it pay to use my 1.25" UV/IR filter in the filter wheel to capture a bit of RGB to go with my narrow band images?
This is a great thread for the QHY8. Maybe we should make it a sticky, moderators?
I couldn't find it in here, but did I read some where about reflections pertaining to the filter glass in the noise piece of the QHY8? If I want to do RGB with the camera, do I need to use the UV/IR glass or can I take it out and just use the extension on the front of the nose piece with out the UV/IR glass and the MPCC? If I'm using a reflector, how does this affect my images in respect to star bloat/bleeding, UV or IR saturation? I have a 1.25 inch filter wheel that I'm gonna use(loss of field, vignetting, etc all understood already) with Ha, OIII & SII filters, so I don't need UV/IR for those, do I? Would it pay to use my 1.25" UV/IR filter in the filter wheel to capture a bit of RGB to go with my narrow band images?
This is a great thread for the QHY8. Maybe we should make it a sticky, moderators?
You need a IR block for the color chip, as IR will bloat your stars because it will pass thru the filters you place in line (Unless they themselves have IR Blcok).
Leave the IR block in line.
I couldn't find it in here, but did I read some where about reflections pertaining to the filter glass in the noise piece of the QHY8? If I want to do RGB with the camera, do I need to use the UV/IR glass or can I take it out and just use the extension on the front of the nose piece with out the UV/IR glass and the MPCC? If I'm using a reflector, how does this affect my images in respect to star bloat/bleeding, UV or IR saturation? I have a 1.25 inch filter wheel that I'm gonna use(loss of field, vignetting, etc all understood already) with Ha, OIII & SII filters, so I don't need UV/IR for those, do I? Would it pay to use my 1.25" UV/IR filter in the filter wheel to capture a bit of RGB to go with my narrow band images?
I have a null adaptor which is a nosepiece without any glass. If you use any nosepiece with the MPCC you will get bright secondary reflections on bright stars. Not too bad on the UV/IR but a shocker with the clear one. For example you won't be able to image the HH or the pleiades without reflections but a lot of other targets won't be affected, like diffuse nebulae (i.e tarantula, eta carina, etc...)
When doing narrow band there is no need to have extra glass in the optical train. Just your NB filter and the MPCC on top of the null adaptor.
I have a null adaptor which is a nosepiece without any glass. If you use any nosepiece with the MPCC you will get bright secondary reflections on bright stars. Not too bad on the UV/IR but a shocker with the clear one. For example you won't be able to image the HH or the pleiades without reflections but a lot of other targets won't be affected, like diffuse nebulae (i.e tarantula, eta carina, etc...)
When doing narrow band there is no need to have extra glass in the optical train. Just your NB filter and the MPCC on top of the null adaptor.
Yo Marc, i was under the impression that you couldnt do NB imaging with an OSC Camera, and if you wanted to image at different wavelengths, then you had to do this via mono and a filter, isnt this the case?
Ok, so we have an opposite here. When you image without a glass in the noise piece Marc, how do you control the IR bloat of the stars Gama talks about? This sort of answers my own question, which is to use my Astronomic IR filter in the wheel for RGB shots. Ha, SII & OIII should supress the IR, at least I've never used them with my Meade DSI Pro II, but that is a mono camera.
Yo Marc, i was under the impression that you couldnt do NB imaging with an OSC Camera, and if you wanted to image at different wavelengths, then you had to do this via mono and a filter, isnt this the case?
Nope. The QHY8 works fine for NB pics. I posted a lot of NB shots on these forums done with the QHY8 and NB filters. Ha & Sii go into the red pixels so you debayer and keep the red only (monochrome image). Oiii goes in the blue and the green and you do the same.
Quote:
Originally Posted by TheDecepticon
Ok, so we have an opposite here. When you image without a glass in the noise piece Marc, how do you control the IR bloat of the stars Gama talks about? This sort of answers my own question, which is to use my Astronomic IR filter in the wheel for RGB shots. Ha, SII & OIII should supress the IR, at least I've never used them with my Meade DSI Pro II, but that is a mono camera.
I wouldn't know about a filter wheel as I never used one but the reflections I was having were happening between the CCD and the MPCC. That's why I got rid of any extra glass in that area. I now put any filters before the MPCC, so that's the first glass the light hits. Whether it's a Ha, Sii, Oiii, or the UV/IR filter.