dweller25

Just bumping this as a reminder for Wednesday evening….

The Heritage 100 will have better light gathering than your 70mm refractor, no chromatic aberration and is very cheap so no worries if you break it whilst hiking.

Hello @tico Going from 80mm to 100mm is a good jump in performance 👍 If I did not already have a 4” Takahashi I would buy that Vixen 103Swt in the for sale section.

@quasar117 Here is a useful summary of optical tests. BUT do bear in mind that what really counts is how the views at perfect focus look.

Yes, apart from the spikes that is how Aldeberan looked tonight compared to the dimmer stars in the same field of view - but with an airy disk.

@quasar117 I have just been out with the Takahashi 4” F/8 refractor. Jupiter at 11’ high is too low for any meaningful observation now for me. I spent some time looking at Aldeberan which was 24’ high at x150 power. It appeared bright, unsharp and unsteady, the dimmer stars in the same field of view were more stable and sharper. At perfect focus Aldeberan showed an unsteady airy disk, either side of focus did show an unstable airy pattern that was identical. This is just a data point for you to compare with your observations 👍 To summarise, this is what I would expect from poor seeing and low altitude observing. Had to observe from the conservatory as I have a bad back, so had a very limited view and could not look any higher !

See here https://www.cloudynights.com/topic/611161-doubts-about-taka-fc100d-star-test/ But - all that matters is the image at perfect focus 👍

Are you seeing any of these ?

Pick a very high star for best seeing

Yes, perhaps the better compromise would be F/5 ?

Moving thin clouds = not the best conditions. It may be better tonight, I plan to take out my 4”……….

Collimato perfecto 🙂👍

Hello @powerlord It’s fine not to go out every clear night - that can be hard work - it needs to be FUN 👍 You are not alone the S.A.D thing is easily developed over the winter, but spring is here now and the weather is getting warmer 🙂 I would suggest a gentle reboot with a pair of Binoculars or perhaps use your 90mm refractor for some visual stuff. How about moving to a bit of Sun observing/imaging ? As long as you enjoy it you cannot go wrong.

Really nice images 👍

The seeing on Tuesday evening was VERY poor. Even Jupiter was twinkling to the naked eye 😱

Good luck Rob 👍

Vulcans always tell the truth 🙂

There is also a 7mm Pentax XW, which barlowed will give x285 🙂

I fitted a fan on the back of the Newt and pulled air out, it immediately removed the boundary layer 👍

There is a 5mm Pentax XW in the for sale section 🙂

Looking good 👍

My findings are about the same as @vlaiv’s calculations. 90% of my observing is planetary. I find maximum useful magnification is 1.5x the aperture of the telescope in mm’s. So the 100mm refractor would ideally be x150, but I often go to x180 ! The OO 1/10th wave 200mm F/6 Newt would ideally be x300, but I rarely go past x250 ! Magnifications beyond the “ideal” show a bigger image but do not show any more detail. However, UK seeing conditions can often limit this to around x250 or less sometimes. Exit pupil also plays a part.

The OP revisited a few hours ago, hopefully he/she got the information needed from the constructive posts.

What a classy looking scope John 👍

Hello and welcome to SGL 🙂