Televue Pearl River f5 Genesis

[Stu]

Stu,

Probably closer to 30 years old!

Caldwell,

I see you have an ED120 - if it's as good as my ED80 pro that should also give some great views...

That doesn't help either Ken! I've had my eye on a larger frac for a while too, and was thinking the 120ED might do the trick!

Stu

[Stu]

Remarkably, the forecast is looking very good for tonight, so may be able to give the Genesis a little try out. Not ideal with the moon being just past full but I'll try to get out early before it is too high. Will be a chance to check out the CA on the terminator too.....

Stu

[Naemeth]

Looks beautiful, hope you get a first light tonight .

[John]

Have fun Stu 

Are you going to change your user name soon then ? "BigFracStu" 

[Stu]

Have fun Stu

Are you going to change your user name soon then ? "BigFracStu"

:-)

I think I might have to at this rate! I keep hatching plans which involve selling everything (including the mak and the children) to afford a decent 5 or 6" ED or triplet refractor!! :-)

Stu

[Stu]

So, I managed a first light last night but despite it being clear (and cold!) the seeing was really quite bad so everything was twinkling and blurring away. Combined with the moon, it did not make for easy viewing :-(

I set the Genesis up on the Giro II, not bothering with the counter balance bar or weight. The mount would have been smoother with it, but was manageable without. I used a 2" diagonal and tried a variety of eyepieces through the evening. The scope feels very solidly built, though not as 'nuggety' as the 76. The focuser is buttery smooth and finding focus is simple despite the lack of a dual speed. The dew shield slides smoothly and seemed effective, although I did have a dew strip on, set very low just to keep things under control, it was below freezing when I was observing.

First bad news was that the 17mm ethos worked beautifully in the Genesis so I think it may well have to stay! The 21mm was showing signs of field curvature but the 17 gave a 3.4 degree flat field, very nice. Need to try the 31t5 as I expect that to be lovely but needs darker skies really.

There is CA present, definitely, but it appears well controlled. On the lunar terminator it really did not impact the view when in focus, around the limb there was a greenish hue. Vega also showed some CA but not objectionable.

I tried for the double double with a 10mm Delos ie x50. I could see how it would be possible to split at this level and might just have glimpsed a split in one pair but the seeing really wasn't up to it. Will keeping trying.

Four widefield 'objects' really stood out as being wonderful when viewed through the scope, I guess showing the benefit of the faster optics and being able to use shorter focal length eps. This gives a smaller exit pupil and darker sky background whilst maintaining the fov. As examples of this, in my Astrotech 106mm I need to use a 31t5 to give me a 3.68 degree fov with a 4.8mm exit pupil. With the Genesis, I can use the 17mm Ethos giving 3.4 degrees with a 3.4mm exit pupil and it makes a noticeable difference, particularly under my skies. I was finding that just panning around I was locating and seeing far more clusters, even with the moon present than I normally would.

So, the four.....

Coathanger. With the 17mm Ethos this was very nicely framed, nice dark background and sharp stars. Often best seen in binoculars but the 3.4 degree fov made it very nice.

The Double Cluster, of course. This fitted comfortably into the fov with a 10mm Delos and looked fabulous! Wonderful star colours, tiny pinpoint faint stars showing through and all framed beautifully with room to spare. Notwithstanding the moon, the sky background was pretty dark so it made for a lovely view.

Caroline's Rose. Confession time..... I've never knowingly seen this before!! Another confession, I just found it accidentally whilst panning around the area (looking for the DC!!) In both the 10 and 8mm Delos it looked lovely, can't wait for a darker sky but the combination of the exit pupil and star colour and definition was wonderful. Sweeping swirls of stars seen for the first time (only been observing 14 years after all!!!)

Kemble's Cascade. Normally seen in binos, but again the 17mm Ethos allowed this to be viewed in its entirety with a decently dark sky background. NGC1502 was very clear, with the double star very nicely showing and a scattering of faint stars also resolved very well given the conditions. Often this gets swallowed up by LP, so I am assuming again that it is the ability to get a darker sky which is allowing me to resolve them better in the Genesis.

I had a quick try on M42, and whilst the trapezium showed clearly, it was too low in the murk over houses to have much of a chance. Likewise with Jupiter, plenty of colour showing with it low down over houses, but also a decent amount of detail beyond the normal two belts from the quick look I had.

Andromeda was too washed out by the moon to be much cop, but Alberio was lovely, very nice star colours and definition.

So, brief summary. The Genesis performed pretty much as expected, though better in some ways. The high magnification performance was in line with my expectations, CA was maybe a little worse than expected although the conditions were not very good at all which would not have helped, so I am hoping for better in future. The seeing was horrid so I could not resolve the brighter stars or split the double double, but I could certainly see the potential. The Widefield performance was as good, if not better than expected. Particularly under my horrid skies, it gives me a real benefit in terms of a dark sky background and ability to resolve clusters with much greater satisfaction than I had been doing. I am really looking forward to using it under a properly dark sky, where it should be amazing.

Will report back more as soon as I get a chance.

Cheers,

Stu

[Mark at Beaufort]

Stu what a fantastic observing report and I am so pleased that the Genesis has come up to the mark. I must admit I like observing the Caroline's Rose cluster (NGC 7789) so you are in for a further treat when the skies are better.

Are you coming over to SGL9 so we can make us even more envious.

[John]

Great report Stu - I loved reading it 

[Stu]

Stu what a fantastic observing report and I am so pleased that the Genesis has come up to the mark. I must admit I like observing the Caroline's Rose cluster (NGC 7789) so you are in for a further treat when the skies are better.

Are you coming over to SGL9 so we can make us even more envious.

Thanks very much Mark. Yes, it's very pleasing, I bought the scope for Widefield viewing and it does excel at that.

I'm not able to make it to SGL9, though am planning on trying to get to SGL10 so hopefully meet you there? I normally just do PSP but hopefully can squeeze in another one with enough warning!

Stu

[ollypenrice]

Great reading and very balanced. I wonder if clearer skies will reduce the CA. Perhaps they will.

Olly

[Stu]

Great reading and very balanced. I wonder if clearer skies will reduce the CA. Perhaps they will.

Olly

Thanks Olly, yes, the conditions weren't great so I am sure things will improve with better seeing.

Jupiter was low down so didn't really have much chance.

The star test looked pretty good to me, collimation not perfect but close. How tricky is it to adjust? Will probably leave as is at least until I've tried under better skies.

Cheers,

Stu

[NGC 1502]

Thanks Olly, yes, the conditions weren't great so I am sure things will improve with better seeing.

Jupiter was low down so didn't really have much chance.

The star test looked pretty good to me, collimation not perfect but close. How tricky is it to adjust? Will probably leave as is at least until I've tried under better skies.

Cheers,

Stu

Hi Stu, as far as I know, all TV refractors are collimated in the same way, by slacking off the 3 lens securing screws (after digging out the filler in the screwheads) and adjusting the tip / tilt of the lens cell.   This does not disturb the lens elements within the cell, just the lens cell as a unit.  I think that a bit of basic DIY skill is adequate, but please go carefully, and leave it as it is if you are not confident.   Those earier TV refractors used imperial head allen keys, so you need a good set of the smaller imperial sizes, I definitely wouldn't try to make do with metric ones. Don't know if the later TVs have stayed with imperial allen head screws, or moved to metric.

Link here http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Board/refractors/Number/5421201/page/0/view/collapsed/sb/5/o/all/fpart/1  it contains info on how it's done, it is about the NP101, but the principal of adjusting the lens cell is the same. (The NP101s rear elements are fixed). Ignore the moans in the link 

Regards, Ed.

Edit - I'm sure I read that Olly Penrice on here collimated a TV Genesis this way, you could PM him, if he doesn't see this.

[Stu]

Hi Stu, as far as I know, all TV refractors are collimated in the same way, by slacking off the 3 lens securing screws (after digging out the filler in the screwheads) and adjusting the tip / tilt of the lens cell. This does not disturb the lens elements within the cell, just the lens cell as a unit. I think that a bit of basic DIY skill is adequate, but please go carefully, and leave it as it is if you are not confident. Those earier TV refractors used imperial head allen keys, so you need a good set of the smaller imperial sizes, I definitely wouldn't try to make do with metric ones. Don't know if the later TVs have stayed with imperial allen head screws, or moved to metric.

Link here http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Board/refractors/Number/5421201/page/0/view/collapsed/sb/5/o/all/fpart/1 it contains info on how it's done, it is about the NP101, but the principal of adjusting the lens cell is the same. (The NP101s rear elements are fixed). Ignore the moans in the link

Regards, Ed.

Many thanks Ed, that's very helpful. I have imperial Allen keys, and the filler in the heads has already been removed so I guess it has already been done at least once. Will have a look when I get a chance and get familiar with it before attempting anything. I'll give it another go under better seeing conditions before trying anything anyway, it's not far out as it is.

Cheers,

Stu

[Stu]

Edit - I'm sure I read that Olly Penrice on here collimated a TV Genesis this way, you could PM him, if he doesn't see this.

Thank Ed, I have been in touch with Olly, who gave similar advice. The link you posted was useful thank you, I was not clear how to go about it, and the fact that it is the lens cell that is held by the three Allen keys so it's all good info.

Cheers,

Stu

[ollypenrice]

The method described on CN is NOT  the same as that which I received directly from a TV optician when I telephoned them for advice. Mallets?? Not for me.

The loosening of the allen screws after picking out the resin is correct.

TV then advised making an artificial star using a small ballbearing glued to mat black card and illuminated from in front with a torch offset from your line of sight. Make the distance as long as you can. (I did it in a condom warehouse but other warehouses would do just as well!!  ) This will give a better point source than a pinhole in my view. (I tested the ballbearing setup using a well collimated Nikon Birder and it gave a perfect star test.)

With the screws loosened a little and the scope just out of focus, move the lens cell with your fingers (mallet free!!!!) until you get a perfectly circular diffraction pattern. I expected this to be murder. It wasn't. I even felt a slight mechanical 'click' at the moment when the circle came right. Mine was miles out at first with a point of light and spikes off to one side. No circles. Once you have a nice circular diffraction pattern you gently tighten the screws. job done.

I would just reiterate that all of this came straight from TeleVue over the phone. They were absolutely charming and in no rush, allowing me to take notes and ask for clarification. One point I'd stress; I asked if you used the three screws to push the cell into the right place as with finder scopes and the answer was a decisive NO.  They said just use your fingers.

Olly

[Stu]

Thanks for the clarification Olly. I think I would have resisted using a mallet just as a precaution anyway!! :-)

The only thing I don't have clear in my head currently is exactly what the cell looks like and where to push. I'm sure it will become obvious when I have a look at the scope.

I won't ask what you were doing in the condom warehouse...... I lack such access so will have to make do with my longish garden.

Cheers,

Stu

[ollypenrice]

Thanks for the clarification Olly. I think I would have resisted using a mallet just as a precaution anyway!! :-)

The only thing I don't have clear in my head currently is exactly what the cell looks like and where to push. I'm sure it will become obvious when I have a look at the scope.

I won't ask what you were doing in the condom warehouse...... I lack such access so will have to make do with my longish garden.

Cheers,

Stu

The cell is the whole black thing at the front. It moves as one relative to the cream coloured tube and will move logically once you have the srews loosened. SInce you are not far out I woudn't loosen the screws by much.

Olly

PS, What was I doing in the condom warehouse? Adjusting a telescope. With Helga, Sonia and Katarina.*

*Some of this may be made up...   

[Stu]

Thanks Olly, that makes perfect sense now, I was expecting the lens cell to be seated within the main black piece which the dew shield slides over. Your clear description, using simple language such as 'the big black thing' and 'the long white tube' have certainly helped me, with my pea sized intellect, understand how it works! :-)

I fear any retort I give to your last point may land me in trouble so I will leave it there :-)

Cheers,

Stu

[Stardust]

Glad is turned out to be a good scope, It certainly looks better than it once did with a cheery hammerite paint job. 

Televues do feel like they will last for ever. Nice report

[Stu]

Thanks Stardust. Almost sounds like you know of the scope or have seen it before?

Stu

[ollypenrice]

Or was Stardust referring to one of the TV finishes like this?  http://www.google.fr/imgres?imgurl=http://www.company7.com/televue/graphics/tvpronto.gif&imgrefurl=http://www.company7.com/televue/telescopes/pronto.html&h=330&w=602&sz=64&tbnid=8GZRDE3JEA79rM:&tbnh=90&tbnw=164&zoom=1&usg=__KkdAP8HHIjXwmGtnktqpf6F2k1A=&docid=58WdgXvROG04-M&sa=X&ei=ZcWNUsTkNJS00QXYn4GwDg&ved=0CDcQ9QEwAw&dur=515

I quite like them, myself, though my own Pronto is white. An adorable little scope.

Olly

[Naemeth]

Nice report Stu, now I've finally had a chance to read it properly .

[Stu]

Or was Stardust referring to one of the TV finishes like this? http://www.google.fr/imgres?imgurl=http://www.company7.com/televue/graphics/tvpronto.gif&imgrefurl=http://www.company7.com/televue/telescopes/pronto.html&h=330&w=602&sz=64&tbnid=8GZRDE3JEA79rM:&tbnh=90&tbnw=164&zoom=1&usg=__KkdAP8HHIjXwmGtnktqpf6F2k1A=&docid=58WdgXvROG04-M&sa=X&ei=ZcWNUsTkNJS00QXYn4GwDg&ved=0CDcQ9QEwAw&dur=515

I quite like them, myself, though my own Pronto is white. An adorable little scope.

Olly

Ah yes, possibly. Was a little confused as I haven't seen the Genesis in that type of finish, just the flat white. My 76 has same 'bumpy' finish and I do like it. I possibly would have preferred the green but all my kit is now black and white so it all matches much better.

Stu

[Stardust]

Thanks Stardust. Almost sounds like you know of the scope or have seen it before?

Stu

I'll drop you a pm

[Stu]

Many thanks