First light on flextube 300p

[BiggarDigger]

Hi everyone, it's been a long time since I posted.  Life in general has got in the way of stargazing this year.  Family and very heavy work commitments plus a house move have combined to limit what I could do so far.

However, the fires still burn and I recently stumbled upon a 9 month old "unused" used Flextube 300p on eBay for a very decent price.  A colleague has been interested in buying my 200p dob for a while, so it seemed to good an opportunity to miss.

The previous owner of the 300p was a complete newcommer and had bought too large for a first scope.  I suspect it had been an impulse purchase and sadly, they became disillusioned with its size and gave up without ever using it.  They had made quite a mess of the colimination.  The secondary was way off, while the primary also need a fair bit of tweaking too.  After an hour or so back and forth with both Cheshire and laser this afternoon it's not perfect, but it'll do for now.

The rain and gales cleared tonight and clear skies beckoned. Our new house has pretty extreme light polution with an LED street light no more than 15 feet from the back fence shining directly into the garden.  The light is so strong and harsh to be painful to look at and there are no dark corners to hide in, so the backgarden is now really limited now to test sessions such as this.  I've scouted a few darker locations nearby and they seem to be pretty good with my old 8 inch dob, but tonight, with a new scope, I wanted to be close to home in case I needed a hand or had forgot something.

So, by 9pm I was outside with a combination of 27, 18 and 12mm Starguider EP's and an observing hood to try cutout glare.

I use a Wixey look-alike digital angle gauge and that seemed to work fine on the new beast.  M31 was much brighter than in the 200p.  Unfortunately M34 was not visible due to light pouring into the tube from the street light.  The double cluster in Perseus was awesome despite external washing of light.

Mars showed surface features, but was in fact almost painful to observe with diffraction spikes and a bit of turbulence making it difficult to observe for a long period of time.

Turn around and with the aid of the angle gauge pop straight onto the Dumbell then over to the Ring nebula, both of which were much brighter and more defined than with the 8 inch tube.  A hint of colour in M57 was visible even when looking north west towards the town. Plenty of other open and closed clusters came and went.  Up to M81 and 82, bright and clearly defined.

Spent a while just messing with the scope and getting used to it.  The previous owner had removed thd 9x50 viewfinder and mounted a telrad base directly over the screw holes.  That will need to be moved, as I use both telrad and 9x50 to navigate around, and with the severe light pollution in the backgarden now, it's very difficult to star hop with just the telrad.

The scope is a heavy piece of kit, but not unmanageable.  The base is a bit awkward being much heavier than the 200p, but it should be fine after getting used to it over a few sessions.  For the ota, one hand on the bottom rim around the primary and the other around the lip between the two halves of the seems to give a good balance.

One thing I was pleasantly surprised at is the addition of a lazy Susan bearing.  It makes a tremendous difference compared to the Teflon bearings of the 200p.

Overall I'm pretty pleased with the new acquisition.  Next year I may retrofit a Nexus DSC to help with navigation, but for now it seems a great piece of kit.

The darker sites nearby appear to be around bottle 4ish and it should excel there. Thirty minutes drive there are sites close to where we used to live: I can achieve bortle 3 which should be awesome with the 12 inch appeture.

I have a week off at new moon in November, so keeping fingers crossed for a good session or two then.  From the mid range weather forecast however, it does seem that a larger appeture attracts more clouds!

Stay safe and well everyone.

Clear skies!

Richard

Edited October 25, 2020 by BiggarDigger

[RobertI]

Sounds really promising, that 12” under dark skies should be awesome. 

[procky1845]

@BiggarDigger thanks for the report.

I also have an 8" dob and have been considering for a couple of years if I should be upgrading to something bigger.

The thing that puts me off is that I remember somebody once said to me at my local astro society when I was just getting started that they had upgraded to a bigger dob and regretted it because under light pollution the background sky was so much brighter and made the overall view a bit washed out. As somebody who primarily observes from my light polluted back garden this is obviously a concern.

What is your opinion on this? Presumably the DSO's also in turn get brighter due to the extra aperture but I've never been brave enough to take the plunge as I love my 8" and don't want to ultimately regret it!

Any thoughts on this would be greatly appreciated!

Thanks,

Lee

[BiggarDigger]

49 minutes ago, procky1845 said:

@BiggarDigger thanks for the report.

I also have an 8" dob and have been considering for a couple of years if I should be upgrading to something bigger.

The thing that puts me off is that I remember somebody once said to me at my local astro society when I was just getting started that they had upgraded to a bigger dob and regretted it because under light pollution the background sky was so much brighter and made the overall view a bit washed out....

Hi Lee, I can only comment based on 3 hours of comparing the two, so others here will have far more experience.

Looking north west over the central belt of Scotland, the background sky was brighter, but M57 and M27 were much brighter (and with structure visible) than through the 8 inch dob at my old darkish sky site.  M81 and M82 to the north were similarly brighter, but I have observed better at the old place.

To the south it was almost a non starter due to the intense streetlight shining directly at me.  But that was the same with the 8 inch.  The core of M31 was brighter than with the old scope, as were its companions, but the true extent of the galaxy was not visible and M34 was not to be seen at all.

I should stress that in that direction the streetlight is so intense that it is much brighter than full moon in the garden.  I also don't yet have a light shroud, so direct light from the street light was undoubtedly leaking into both primary and secondary.

I suspect that my back garden is a non starter due to the intense light, but in general I think the larger appeture would balance out the light polution on DSO's

10 minutes away I can escape the local street lights, but will still have the light pollution to the North.  It will be interesting to judge the difference there compared to home.

Richard 

Edited October 25, 2020 by BiggarDigger
Bloomin auto correct on phone...

[BiggarDigger]

The offending light...

[laudropb]

A good start with the new scope Richard. I had the same problem when the council put in LED lights. I did manage to persuade them to put on shielding as the new light was about 3 feet higher than the old one and was lighting up 2 of my bedrooms. This made a big difference, but I was also lucky in that the light is to the front of the house and I can use the building to shade it out.

[Les Ewan]

HI Richard,

I know Biggar well ,my brother lives just south of there. Has the hogmanay bonfire started to appear yet?! He stays near the Cornhouse Hotel where they think its a good idea to light up the trees at night.🤬 My brother and his wife are not bothered as they are not at all interested in astronomy ,but it really annoys me when I visit.

I have a flextube dob as well and also the optical finder and a telrad its a very handy combination(when the telrad isn't dewed up that is). We all know what a flextube dob looks like but it would be nice to see a image of it,good star watching and clear skies.

Edited October 25, 2020 by Les Ewan

[John]

Nice report - 12 inches is a great aperture to have to explore the night sky

Globular clusters are one example of a deep sky object that really benefits from increased aperture. With the 12 inch at around 150x bright globular clusters such as Messier 5 and 13 are resolved deep into their core's and are really starting to look like the images you see of them.

 

 

Edited October 25, 2020 by John

[BiggarDigger]

5 hours ago, Les Ewan said:

HI Richard,

I know Biggar well ,my brother lives just south of there. Has the hogmanay bonfire started to appear yet?! He stays near the Cornhouse Hotel where they think its a good idea to light up the trees at night.🤬 My brother and his wife are not bothered as they are not at all interested in astronomy ,but it really annoys me when I visit.

I have a flextube dob as well and also the optical finder and a telrad its a very handy combination(when the telrad isn't dewed up that is). We all know what a flextube dob looks like but it would be nice to see a image of it,good star watching and clear skies.

We used to stay a few miles west of Biggar, but times change, so a couple of months ago we moved a dozen or so miles north towards central belt.

The old place had stunning skies.  Thus far, away from "that light" the light polution is not too bad to the south at the new place.  North is a big fuzz of central Scotland towns and cities.

Under clear skies, away from the town, the new scope should be rather nice.

Richard 

[kirkster501]

300P is an amazing scope - I have one too so know very well    In a dark sky they are capable of spectacular things.

Shame for the original buyer, but your gain.  These things increase in size almost exponentially with aperture.  I had a 200P for ages and was astonished how much bigger the 300P is.  I can't even guess how big the 400P must be 😱

[Whistlin Bob]

14 hours ago, procky1845 said:

somebody once said to me at my local astro society when I was just getting started that they had upgraded to a bigger dob and regretted it because under light pollution the background sky was so much brighter and made the overall view a bit washed out.

Congratulations on your 300p @BiggarDigger- sounds brilliant. I umm'ed and aaah'ed about a bigger scope for ages before taking the plunge. I've never regretted it for a second.

@procky1845 many people said the same to me- "you'll just pick up more light pollution" and of course this is true. But everything increases at the same rate and so on fainter objects, there's more light altogether and you still see more of the object. I have a 200p and a 350. In equal conditions (and I've used both scopes in Bortle 2 up to 6, home is Bortle 5) the 200p, good though it is, gets blown away by the bigger scope. The downside is that it's a big beast and takes a while to assemble and collimate, other than that it's brilliant!

 

[popeye85]

@BiggarDigger  nice report.

    I've just got the same scope after upgrading from the 8" but, alas, I have not had a chance to get it out yet apart from a quick look at the moon!!! Needless to say I'm itching to get out-especially since I also got a set of es82°s to go with it-hopefully this combination will open up the skies for me!

I'm along in East Lothian so although skies not as bad as they are a bit further west, it is still worth a drive south to get to the dark skies.

Edited October 26, 2020 by popeye85

[Barry-W-Fenner]

Great choice of scope.  I can have my 300p set up and fine tunes in under 10mins.

I took a similar path to you and went from a 200p to the 300p I was also pleasenty surprised by the bearing in the base, it is a huge improvement over the Teflon, I think they should offer the bearing on the 200p model.

I have added my RACI finder and a regal quick finder, they compliment each other well while dso hunting.  I also added a duel speed skywatcher focuser while was a quick 10min job, this was a nice improvement over the standard focuser to achieve fine focus and has smaller less cumbersome wheels to adjust focus. This is not essential though.

An astrozap dew Shield made a big difference and imo is essential to keep the stray light out, In addition to this I have flocked the whole tube internally both top and bottom sections, it is now pitch black when looking down the tube and there is no sign on internal reflection. This had a noticeable improvement on contrast for me in my bortle 6 location.

The next thing I would like is an astro essentials light shield for the secondary mirror, this will help with stray light entering the back of the focus tube.

These additions might not be as critical to yourself as you are in bortle 3-4 locations. For me I need every advantage I can get 😁

All in all I love the scope and can't wait to get it to a dark sky location at some point to unlock its potential.

Regards

Baz

 

 

[Alan White]

Sounds a great purchase and step up in aperture.

The addition of a Nexus DSC sounds a very sound move, it’s what I have done with my OOUK 250 and highly rate the upgrade, it brings the scope to life at home where I have LP issues.

 

[popeye85]

@Barry-W-Fenner just out of interest how long do you leave yours to cool down for? (Just incase I get a chance to get mine out in the next year 🤦‍♂️🤦‍♂️🤦‍♂️)

Edited October 28, 2020 by popeye85

[Barry-W-Fenner]

19 minutes ago, popeye85 said:

@Barry-W-Fenner just out of interest how long do you leave yours to cook down for? (Just incase I get a chance to get mine out in the next year 🤦‍♂️🤦‍♂️🤦‍♂️)

Hi Popeye85

I tend to give the scope 30 to 60mins cool down time.

I store it in a cool utility room so it doesn't tend to take to long.

As you say opportunity's to get the 300p out have been few and far between..