Deadlake

Can SkySafari be set to green instead of red for night time viewing. The eye is less sensitive to red than green, so if using green the screen brightness can be turned down.

Tamiji would 😁😁😁

Hopefully, don’t want to feel it’s the same as when Vixen stopped HR production and then everyone rushed to get the remaining sets….

Anyone compared a TOE 3.3 to HR 3.6 mm?

Presume this is cool down related?

In an idea world to be as portable as possible a harmonic drive would be the lightest tracking mount running in Alt-Z mode. However thats quite an expensive option. I suspect the AZ100 tracking will be close to an EQ mount in cost but for the payload (up to 20 kg each side) will weight less. A ScopeTech Zero is also great but the scope will need to be less than 7 kg (Hence 115 mm ) to be usable, but much more portable.

From above I mentioned "Maybe a 115-120 mm would be a compromise?" I mentioned the 115-120 mm size as the 125 mm is around 7.8 kg which would rule out quite a few light weight mounts...

Are there encoders for these mounts at all?

There is a review of the Noh mount here: https://www.cloudynights.com/articles/cat/user-reviews/field-test-the-noh-ct-20-alt-az-mount-r3313 I was tempted however slow mo comes up, then then AZ75 as well. I find tracking mounts better on the moon where any vibration causes wobble it degraded max magnification I can use.

The 4" is so much easier to get out for sure, however the 5" is more rewarding and being able grab a one hour session without thermal cooling makes for best use of time. Maybe a 115-120 mm would be a compromise? You've touched on mounting, maybe the weight of the mount should guide you? Any scope over 6 kg starts to rule out a lot of mobile mounts if that's important to you.

Indeed it is all physics, side by side these two scopes from APM, the 5" shows more stars/planetary detail than the 4". I suspect I'll never have the seeing to tell the difference between the Vixen 4" I have and the APM 4", the APM lens is brighter due to the glass used, is more compact if heavier.

You will never know unless you have the Takahashi tested. The point is that unless you are moving to say the Atacama Desert you will never see any benefit from having higher the 0.95 Strehl... I will always take the 5" out due to this, even if the 4" is so much portable. Your eyes will thank you for the extra aperture...

If you are considering a 100 DZ the below scope is within your budget https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGTEC130-7 This is cheaper marginally then the Tak, however it has a minimum Strehl of 0.95, meaning due to seeing etc I don’t think you will be visually able to tell the difference with a lens with a higher Strehl number, however flourite lens appear brighter to the eye. Also you will see more stars through a 5” compared to the 4”. I have both doublets and triplets and really apart from weight I don’t really see cool-down as an argument to go for the doublet.

Yes, I know, if only the US would move over too. However I suspect unless they have a Mariner type incident (imperial to metric conversion in software) this will never happen. I know the thread pitch argument etc for not moving however outside of US causes no problems...

UNC and Imperial I thought where different.

https://www.telescopengineering.com/wp-content/uploads/2020/01/160-Manual.pdf Sew page 3, other source available: 6.5 Finder Base Screw Holes (Plugged 6.3 with (2), 8-32 Button Head Screws)

The starlight focuser finder scope mounting point has UNC 8-32 button screws. The hex like bolt head is somewhere between a 2-2.5 mm hex bolt head size for an Allen key. Searching an Amazon I cannot find an equivalent set of UNC sized Allen keys, do they even exist?

I thinking the TOE is a little smoother in it's image where the Vixen shows every detail. Both are excellent just more about person preference of presentation of the image. How are you getting with the TOE 2.5 mm? Is it worth having? The HR 3.4 mm and TOE 4 mm are keepers, maybe I should try the TOE 3.3 mm first.

Well here is an AZ100, it handles the weight on both sides quite well.

I've seen a TSA-120 on a Vixen APZ in Alt mode. How realistic would it be to mount a 7 kg scope on the APZ? I'm after a mount which can take a 7-8 kg with slow mo's, this could be it...

I now have a 2" Chroma H-Alpha 3 nm, I'll be able see more with that. But another post...

I can see in the dark😀, however push to on the AZ100 is quite accurate.

Maybe @jetstream will chip in once he has finish playing with his new snowmobile

Astronomik As you can see in the dark easy to get mixed up...

So both the OIII and UHC filter I have are in a UFC holder/draw. Possible I got them mixed up. I rely on where they are stored in a filter pouch.