Hi Fellas, I have been watching this thread with interest. I don't use a newtonian so really have not been able to add anything to the discussion about the MPCC spacing and configuration but I maybe can add a few things now that narrow band imaging has come into the arena....
The QHY8 is very capable in recording NB images. Two methods I have used which seem to be quite reasonable are:
1. Capture using 2x2 binning as the images captured don't make use of the bayer matrix and images captured are mono only and can be stacked and compiled as if it was a truely mono camera.
2. Capture the images as if normal RGB with the NB filter fitted. Depending on the software you use and how narrow the filters band is you will in most cases be able to reduce your image to a luminance only image which contains almost all light which passes the filter again as a mono image. In the case of my capture software (Nebulosity2) it has a menu item under the image menu Keep Lum and discard colour. Again the images can be stacked,colourised and combined to produce very acceptable NB images.
Although the OSC camera is not as sensitive as a mono camera good results can be achieved with NB images without talking very extended image capture sessions compared to the mono camera.
I have tried a lot of capture software and still maintain that nebulosity is one of the best and easiest capture programs available at a reasonable price. It also has a lot of neat little features built in to the processing routines. Well worth having a look at it.
Good luck Fellas. Look forward to seeing some great images.
Although the OSC camera is not as sensitive as a mono camera good results can be achieved with NB images without talking very extended image capture sessions compared to the mono camera.
I have tried a lot of capture software and still maintain that nebulosity is one of the best and easiest capture programs available at a reasonable price. It also has a lot of neat little features built in to the processing routines. Well worth having a look at it.
Good luck Fellas. Look forward to seeing some great images.
Hagar
Really interesting message and has made me was it to NB imaging at one stage. And I agree with you that Nebulosity is the easiest program for capturing. Realy like it.
Allan
It does indeed. But there's not much of it to start with I was told so that would be true for any camera including mono . Although the QHY8 QE is not as good in the reds as in the green so Oiii is certainly much easier to capture. Ha is pretty easy too though in my experience.
Quote:
Originally Posted by marki
I imagine SII data would take a while to collect with a OSC. Is that the case Marc?
1. Capture using 2x2 binning as the images captured don't make use of the bayer matrix and images captured are mono only and can be stacked and compiled as if it was a truely mono camera.
Hi Doug I have tried bin2x2 for Ha (once) and I collected more noise from the other channels than just doing bin1x1 and keeping red only, discarding blue & green. Maybe I'm doing something wrong with bin2x2 but having said that I gave up the idea of binning so I don't have much more to say on it. Do you use bin2x2 a lot?
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.
It is a good thread and full of useful stuff - I will be using this on the 127ED and the Vixen R200SS. I bought the MPCC and the spacer kit from Myastro a while back to use with the nagler eyepieces i had and the meade lightbridge 16 i owned at the time - then i got the qhy8. Reading this i can see the merits of the adjustable adapter. I clicked on the link but they don't list your adapter? is it that custom made that he doesn’t list it? Can you supply the cost of the unit and the exact details you asked him to make?
It does indeed. But there's not much of it to start with I was told so that would be true for any camera including mono . Although the QHY8 QE is not as good in the reds as in the green so Oiii is certainly much easier to capture. Ha is pretty easy too though in my experience.
Thats what I thought Marc, it always took longer to get good SII data with a mono and they are more sensitive then a OSC.
Hi Marc, I used 2x2 a bit when I had the FS102 but since getting the FSQ the pixel scale is rather large when binned so I now just stick to 1 x 1 . Unbinned = 2.99 pixels / arc sec 2 x 2 binned = 5.94 pix / arc sec.
I haven't really given it a try but will get around to it at some stage and see what the results are like. For narrow band I tend to use the method I stated using nebulosity and keeping the Lum layer as the narrow band filters are quite selective in what is passed that you can get away with this method at least with 7 nm Ha or smaller filters. Detail is usually quite good and exposure times are not unreasonable.
Quote:
Originally Posted by multiweb
Hi Doug I have tried bin2x2 for Ha (once) and I collected more noise from the other channels than just doing bin1x1 and keeping red only, discarding blue & green. Maybe I'm doing something wrong with bin2x2 but having said that I gave up the idea of binning so I don't have much more to say on it. Do you use bin2x2 a lot?
Hi David, Peter is a wonderfull dealer to deal with but you will need to send him an email and probably copy in Marcs image of the adapter and he will no doubt be able to help you. He has made me all sorts of bits and pieces over the last couple of years and makes them quite quickly and usually very reasonably priced. His email address is at the bottom of the page. His name is Peter Lee.
Quote:
Originally Posted by h0ughy
It is a good thread and full of useful stuff - I will be using this on the 127ED and the Vixen R200SS. I bought the MPCC and the spacer kit from Myastro a while back to use with the nagler eyepieces i had and the meade lightbridge 16 i owned at the time - then i got the qhy8. Reading this i can see the merits of the adjustable adapter. I clicked on the link but they don't list your adapter? is it that custom made that he doesn’t list it? Can you supply the cost of the unit and the exact details you asked him to make?
It is a good thread and full of useful stuff - I will be using this on the 127ED and the Vixen R200SS. I bought the MPCC and the spacer kit from Myastro a while back to use with the nagler eyepieces i had and the meade lightbridge 16 i owned at the time - then i got the qhy8. Reading this i can see the merits of the adjustable adapter. I clicked on the link but they don't list your adapter? is it that custom made that he doesn’t list it? Can you supply the cost of the unit and the exact details you asked him to make?
Hi David, here's the basic drawing I sent to Peter. You'll have to tweak the distances to suit your scope but the basic concept is there. As PMd you'll have to discuss the specifics with Peter.
For narrow band I tend to use the method I stated using nebulosity
Got it. I re-read the post. I use Neb2 as well but I never used the Keep LUM only option. I usually just load the raw FITS in CCDStack. Will try that - thanks.
Hi David, here's the basic drawing I sent to Peter. You'll have to tweak the distances to suit your scope but the basic concept is there. As PMd you'll have to discuss the specifics with Peter.
thanks - i wonder if there is a need to reinvent the wheel?
thanks - i wonder if there is a need to reinvent the wheel?
More than likely he has kept the manufacturing drawings but that's all that I've got and that I've given him - he worked it out. What I'm saying about sizes is that I'm not familiar with your scopes but it'd be fair to assume it will work in a similar way.
Thanks for supplying the tech drawing of your adapter, I was going to ask you about this. I think it is brilliant.
Do you remember how much it cost. Also, guys, if several of us want it made, do we do it as a group and get a bulk order together, and one person can act as the agent, do the re-posting, payments, etc??
Thanks guys. It makes sense to have something adjustable. I think there is too much money in the rings/spacers business so that would be why this is not mass produced or readily available IMHO Having said that talk to Peter about pricing. I know David is interested too so if he gets enough orders you might get a price for abulk. He might even consider making and stock it in the future, who knows?
Quote:
Originally Posted by TheDecepticon
Thanks for supplying the tech drawing of your adapter, I was going to ask you about this. I think it is brilliant.
Do you remember how much it cost. Also, guys, if several of us want it made, do we do it as a group and get a bulk order together, and one person can act as the agent, do the re-posting, payments, etc??
Quote:
Originally Posted by TheDecepticon
And I forgot to ask, you use this in conjunction with the adapter kit that comes with the MPCC?
I use it with the MPCC only. I don't use any rings that came with the MPCC kit. I also calculated the distances so I could get rid of the nose piece all together, but later on I still bought a null adapter.
May I clarify an issue with the spacing of the MPCC in relation to the film plane (or plane of the CCD in the QHY8). I attach a snippet from the MMPC blurb from the manufacturer which suggests a distance of 55mm from the imageing chip to the outer rim of the T-Ring. Can this be right? I was having a look at Marc's tech drawings that were the basis of the variable adapter he had made by Peter Tan and started counting diatances again and now I am quite at sea over this whole issue. Can someone clariffy please?
Peter
May I clarify an issue with the spacing of the MPCC in relation to the film plane (or plane of the CCD in the QHY8). I attach a snippet from the MMPC blurb from the manufacturer which suggests a distance of 55mm from the imageing chip to the outer rim of the T-Ring. Can this be right? I was having a look at Marc's tech drawings that were the basis of the variable adapter he had made by Peter Tan and started counting diatances again and now I am quite at sea over this whole issue. Can someone clariffy please?
Peter
This is correct: 55mm +/-2mm is the recommended distance by the manufacturer. That may slightly vary depending on the scope/camera combinations you're using though but it's a good point to start from.
This is correct: 55mm +/-2mm is the recommended distance by the manufacturer. That may slightly vary depending on the scope/camera combinations you're using though but it's a good point to start from.
OK. That 55mm +/- 2mm from the CCD image plane to the outer edge of the T-RIng. So with a standard DSLR there is probably no need for the variable adapter you had made. It's use would be with CCD cams such as a QHY8 or Orion where the distance from the CCD chip to the ouser edge of the camera would only be 10-12 mm or so. The variable adapter would allow you to take that up to 55mm and THEN you screw in the MMPC. Have I got that right?
Peter
OK. That 55mm +/- 2mm from the CCD image plane to the outer edge of the T-RIng. So with a standard DSLR there is probably no need for the variable adapter you had made. It's use would be with CCD cams such as a QHY8 or Orion where the distance from the CCD chip to the ouser edge of the camera would only be 10-12 mm or so. The variable adapter would allow you to take that up to 55mm and THEN you screw in the MMPC. Have I got that right?
Peter
QHY8 CCD chip have a distance of 7mm from the chip to the top of outside casing or ~21mm from the chip to the nose piece, therefore you will need ~34mm of adapter spacing to the MPCC.
. Although the QHY8 QE is not as good in the reds as in the green so Oiii is certainly much easier to capture. Ha is pretty easy too though in my experience.
I ended up getting a custom spacer done from 
Having said that talk to Peter about pricing. I know David is interested too so if he gets enough orders you might get a price for abulk. He might even consider making and stock it in the future, who knows?
