Merlin66

Like many filter suppliers the transmission curves only show the wavelengths which would impact on CCD imaging - around 370 - 1100nm. A silicon based CCD/CMOS is only sensitive up to 1100nm. 52% of the total solar energy is in the NIR - 700 - 2500nm. For visual the whole NIR region needs to be considered - up to 2500nm. Looking at the Baader UV-IR filter (and I'm sure others) you'll see significant leakage occurs beyond 1100nm.

Not all/any ND5 filters block all the UV through to IR (350nm to 2500nm) wavelengths.

The existing threaded holes in the OTA fitted the Losmandy dovetail clamps.... no need to drill anything.

Hmmmm, Not for all Astronomical filters

Less wind, average seeing... CaK, White light and Ha. AR 2758 still visible...and a few faint but interesting proms. Usual ED80 with - DIY CaK filter, SM60DS and Baader Wedge. ASI 1600MM

The way to go is to use a mono CMOS which can give a fast frame rate - faster the better. Collect a 500+ frame AVI, run it through Autostakkert3 (freeware) tweak in in Imppg (again free) crop and colour in infranview (free) and you have surprising results. Good time to practise...when Cycle 25 kicks in hopefully there will be plenty of detail to record.

I think also the NIR "leakage" is of concern to some people.

Faculae is visible in white light, plage is visible in H alpha. Different heights in the solar atmosphere......

White caps on the bay!! Blowing a gale..... Unnamed AR and sunspot (!!!) easily visible in CaK. Unfortunately NR and cable problems while trying Ha. Tuning not ideal for the AR, but I've cropped the disk to make it a lttle easier to see. No time to image proms..... No chance to do a white light, but I'd assume the spot would be visible.

Waldemar, The two smaller screws are not connected to the tube ring, they just push against the ring......

Yeah, That's why I said the solution was to replace them with countersunk screws.............................

The two smaller screws on either side of the central M6 screw can be removed...these are only there to provide “cone error” adjustment, and seldom used.

No, always twice the diameter- for any Barlow/ negative lens. the magnification is dependent on the spacing between the lens and The eyepiece/ CCD.

Yeah, This happens when the dovetail is too short for the length of the saddle clamp on the mount..... Some short OTA's don't allow a longer dovetail to be used... The answer I've found is to replace the socket head screws normally used to connect the tube rings to the dovetail, with M6 x25mm countersunk screws and drill out the base of the dovetail to accept the countersink. Not to many other solutions........

What's a 1/3 sensor???? May mean something to a "photographer", but provides no information to us in astronomy. Pixel size and frame size is what matters......

Hmmmm The differences between an HEQ5 "heavy duty" and an HEQ5 pro version...... IMHO I wouldn't try it.

There's an easy and accurate method of measuring a Barlow negative focal length..... Measure the free diameter of the Barlow lens, draw on a card a circle twice this diameter, hold the card behind the Barlow pointed towards the Sun, when the image fills the circle, the distance from the Barlow lens to the card is the focal length. Works for all negative lens.

Or the Carrington solar rotation heliographic longtitude???? https://en.wikipedia.org/wiki/Solar_rotation#Carrington_rotation

ZWO appear to have "spare" fans available on their web page. https://astronomy-imaging-camera.com/product/fan-for-cooledpro-cameras

+1 for irfanview. A great program well worth having.

Hmmm The RJ45 port on the Synscan handcontroller connects to the RJ45 port on the mount........ The RJ12 port on the mount is for the ST-4 guide camera connection.... What were you hoping to achieve??

No experience with the 2" Lunt BF, but I have used the 1.25" Lunt diagonal BF (Ex-60m Lunt PT scope) successfully on my SM60/ ED80 set-up. No issues.

+1 for VMA

AstroArt has the LRD as well as many other filtering options.......http://www.msb-astroart.com/ Try the demo version to check it out.

I strongly disagree with this assessment!!! AstroArt is up there with the best, it has been constantly updated and revised to meet the real needs of the amateurs. It has a very good support forum https://www.astroart-forum.net/forum/ The lastest V7 is very good and well worth trying. http://www.msb-astroart.com/ Check out the review on CN https://www.cloudynights.com/articles/cat/user-reviews/astroart-7-a-review-and-how-to-part-1-r3225 Fabio has looked after his user base and helped spectroscopy users by implementing additional features to make our lives easier. I recommend and use AstroArt.