angryowl

It’s been a while since I’ve posted on here, so here goes. I’m currently using a RASA 11” with the Baader F2 HighSpeed filters (which I believe to have a FWHM of 10nm) and while they’re fine, I am based in Bortle 8 skies and have found that they pass just too much of the light pollution as well. This means I need rather high integration times to reach an acceptable SNR and even then, with so much LP the integrated masters are usually low in contrast. In doing research for a new set of narrower filters, I’ve discovered that finding filters with a small enough FWHM and a high enough

Thanks for the reply Mark I must admit I hadn’t thought of that but now that you mention it, it makes sense. I know I read somewhere that NB filters nowadays use several coatings sometimes more than ten per filter and the idea that one or multiple of these coatings are reacting differently to light emitted from this particular star is indeed interesting. Learn something new everyday...

Hi all, Whilst capturing data over the last clear nights on my latest object, NGC 7822, I noticed a star with an odd profile in the OIII subs but put that down to cosmic rays or some other weird artefact. But after my usual preprocessing, I’m still seeing this strange star in all of the OIII subs and much clearer in the stacked image. The OIII data is a stack of 54 300s subs making for a total of 4.5 hours and similar integration times for Ha and SII. What’s strange is that this only shows up in the OIII data and not the other channels. As can be seen, Ha and SII look completely

Thanks to all who took the time to reply. I have found a QHY5L-IIC which should be delivered any day now. This has a 1.25" body so should be perfect for my setup.

Hi Nikolas, I appreciate you taking the time to reply, but unfortunately the price is a bit out of my range and what I'm willing to spend on this since it'll only be used for polar alignment using SharpCap.

Yes, that's exactly it. A mate of mine found someone selling a QHY5L-IIC which is perfect and am currently communicating with the seller. If this materialises then I'm sorted.

I see, I've attached an image to my original post of my 60mm modified guidescope to better illustrate where the guidecam imaging chip needs to be.

Thanks for replying, but I updated the Ad with more information. I have seen that DMK21 and I also have a DMK41, but these can not be inserted into a 1.25" focuser enough to reach focus with my guidescope.

Looking for a guide camera (CCD or CMOS) with a 1.25" barrel size that could slide into my guidescope focuser. To reach focus with my guidescope the guidecam imaging chip will need to be positioned inside the 1.25" focuser so the camera will need to be inserted almost all the way inside the focuser hence the need for a 1.25" body. Examples of compatible cameras are QHY5 series, Lodestar guide cameras, ZWO ASI 120 mini. This is my guider and roughly how much the camera needs to be inserted into the focuser to reach focus Any make and model considered. Thanks for look

When I tried the OAG lent to me by @souls33k3r I did manage to get the spacing right and guiding gave me pinpoint stars in all exposures. So far the OAG is the only thing I tried that actually works and currently I’m in the process of building a DIY one. The reason I’m not going with a commercial one is that the guide camera body and USB cable get in the light path of the scope and cause weird diffraction spikes whereas with a DIY one, I’m hoping to avoid that. Chip moving inside the camera…wow that’s scary! Glad you got that one sorted as I can see it being hard to solve. Seeing as the i

Oh yeah, that I will do given the opportunity. Perhaps when Ahmed gets his one finished he'll let me throw it on top for a quick test ?

Managed to get out during a clear night last week and tried guiding with the refractor piggy backed on top of the RASA and also with the 60mm guider clamped onto the bottom dovetail of the OTA. I also cleaned up the residual adhesive on the tripod head and sanded the bottom plate of the Mesu down which resulted in a much larger contact area with the tripod head. The results are not really what I expected, but a lot better than before and guiding is more consistent. That being said, guiding with either the 60mm guider or the refractor still doesn’t produce round stars. The elongation is mu

Hi Jakub Welcome to SGL, you’ll find the very helpful and experienced people here will provide invaluable assistance and guidance when dealing with issues such as yours. Don’t yet have a final word on this, but so far it seems like the PTFE pads were only part of the issue and although I can now guide most of the elongation out, it’s definitely still present in most guided subs. In response to your question, I’ve tried anything from 1 second exposures all the way to a minute in most directions in the sky and no elongation whosoever was present in these short exposures. I find th

That makes a lot of sense now, but didn't know any better two years ago when I built the tripod. Looked at the EQ8 and saw that the tripod they sell had PTFE pads and the mount is rated at 50kg, I thought adding 0.5mm thick pads on mine would be a safe bet. However, I'm thinking the EQ8 might have more contact area with those pads than my Mesu did which would make a difference.

Hehehe, thanks mate. Don't want to get too excited as I said it could be only part of the issue, but further testing should confirm.