RobertI

Thanks Chris, that's good to know, I probably should have got the Tal out to confirm it was the conditions and not the scope. I really should know by now that sky conditions are everything and I shouldn't be judging yet. Am I underwhelmed? I shouldn't be because I already know what a 4" frac can do from the Tal, and I had already restrained my expectations (it's only 4" after all), but you can't help hoping for an unexpected surprise, especially when so many people rave about how good 4" ED apos can be. But I've managed to split Mu Cygni (1.4" sep) which is a good start and I am sure under good conditions it will be fab.  

Hi Dominic,

An interesting question to which I don't know the answer, so I have done some googling and according to Skyhound :

" The largest and brightest galaxy is NGC 7320.  It is just visible in a six-inch scope as an elongated hazy patch.  Larger instruments may show mottling in the outer parts.  This galaxy has a much lower redshift and is likely to be between us and the other members of the quintet.

You will need at least an 8-10" scope and dark skies to see the other galaxies of this group, which are apparently part of the same galaxy cluster.  At 100x they appear as a close grouping.  Use higher magnifications to study the individual galaxies."

So I think the answer to your question is 'No'! However the nearby NGC7331 is much brighter and easily visible in a 4" scope. 

Interesting object John. Also not shown in my Cambridge Star Atlas, but Interstellarum shows it in the "visible in 8" scopes" category. Might sniff it out.  

18 minutes ago, RobertI said:

From my own experience moving from a TAL 100 to an ED doublet, the difference between the TAL 100 and the Altair 102ed-r will be mostly in the control of false colour I think. The TAL 100's that I've had have had well figured objectives so will basically show most targets as well as the more expensive ED doublets will but with some false colour around the brighter targets.

The other thing I don't like about the Tal is the yellow colour cast to everything - I assumed this was a result of lower quality glass but is apparently deliberate to reduce the effect of the CA. Not many people seem to mention the yellow colour cast so I guess is not bothersome to most.

I am fully expecting to realise how good the Tal is when I do a side-by-side test with the ED-R!

As a side thought, in retrospect I could probably have met most of my requirements (shorter tube, wider fields, reduced CA, removal of yellow cast) with the cheaper AA Ascent 102ED F7 with FPL-51 glass and costing half the price, but I think would have forever wondered what the ED-R would have been like, and I'm also  hoping to do some sneaky imaging in the future. 

10 hours ago, John said:

Very encouraging 1ist light report

I like to try out new-to-me refractors on some tight binary stars including those of uneven brightness.

Stars such as Delta Cygni and Pi Aquilae are currently well placed for such trials.

From my own experience moving from a TAL 100 to an ED doublet, the difference between the TAL 100 and the Altair 102ed-r will be mostly in the control of false colour I think. The TAL 100's that I've had have had well figured objectives so will basically show most targets as well as the more expensive ED doublets will but with some false colour around the brighter targets.

The faster focal ratio of the Altair will open up options for wider fields of view than the F/10 TAL can achieve though and should be OK on a slightly lighter duty mount.

 

 

 

Thanks for sharing your experience John, I am looking forward to comparing against the Tal, I'm really not expecting much of a performance difference, but will be a bit disappointed the ED scope is not as good! I enjoy observing with two scopes, it's all part of my scope education and is good fun!

I managed a second light last night, in very similar conditions to last time (bright sky, poor to average seeing). Mars was a little better in terms of detail, but still not fabulous. I think it's going to take a while to get a good night for a proper test run.

I did try a tight double - Mu Cygni with mag 4.8 and 6.2 components separated by 1.4"  - I managed to split it (black line between) at around x180 I think, so that's promising.

I also tried a star test with a green filter, and it looked much better than in white light. But I understand a proper star test requires excellent seeing, a well corrected eyepiece and no diagonal - I had the opposite of all three, so probably a pointless test.

Wide field viewing was not much fun with such a bright sky, so again better conditions required.

13 hours ago, mikeDnight said:

I must admit to cheating Chris. I use a binoviewer, which makes a massive difference. 

Interesting Mike, might seem like a stupid question, but does it work better because the use of two eyes allows the brain to work better in identifying patterns, or is there some other effect at play? Probably the subject of multiple threads already!

17 minutes ago, Adam J said:

The ideal is to use a solar continum filter. But you can use a green filter too if you are struggling with the diffraction rings being too dim.

However, yes white light is not a good test for an apo as too much is overlapping to be able to make anything out.

Adam

I do have a green filter so I’ll give that a go. Thanks for the help. 👍

19 minutes ago, Adam J said:

Nice,

I dont think there are any pitfalls to star testing APO scopes so long as you understand that you can expect some under / over correction in red and blue, or perhapse you are thinking of another effect?

Adam

Yes, I read this article which linked to some others and the takeaway for me was not to bother testing in White Light! Another factor is that I star tested my 150PL and the results were abysmal, but the scope has performed faultlessly, so made me wonder whether it was of value anyway.  However, with the 102ED-R  I did try a quick test on a bright star using an OIII filter, and the diffraction rings were perfect and identical inside and outside of focus (though faint), so promising. I didn’t mention this as I was not sure how valid an OIII filter is for testing but I can’t see why this would be a problem? 

First light is an important moment, so despite so-so conditions, I thought I'd relate the first observing session with my new Altair Astro 102ED-R.

I didn't really have a plan and the session was a mix of trying to test out the optics and trying to do some observing. I think I achieved neither very well, but I got the opportunity to observe a very low Jupiter, a slightly wobbly Mars, the Dumbell nebula, a couple of nice coloured doubles and the rising moon. The main takeaways from the session were:

• At F7 (FL=714mm) the scope was a lot easier to observe with than the F10 Tal (FL=1000mm), with the eyepiece in more convenient locations.
• The focuser, which seemed stiff to start with, actually worked really well and was a joy to use.
• There was no noticable CA on the brightest stars and the moon and nicely defined diffraction rings around brighter stars.
• I did push the magnification to 200x on Mars, but was not really seeing much detail apart from the polar cap and the dark southerly region.
• There did seem to be a certain amount of 'scatter' around bright objects, but I really don't know if this is worse than any of my other scopes, and to be honest could be due to my modest eyepieces or even my eyesight, so I'm not worrying about that for now.
• The dumbell was lovely at x72, very bright with hints of structure when viewed with the OIII filter. I think this scope could really excel at deep sky.
• The 38mm Panaview worked nicely for wide fields, but there was distortion on a significant part of the outer FOV - to be expected I guess.

So overall pretty much as I expected from a cursory intial session. Optically I suspect I will find it marginally better than the Tal but without the CA, yellow cast and long tube. I am expecting it to be much better on deep sky though. I guess I was slightly disappointed that I was not 'blown away' by the views, but I also knew that this was only a 100mm scope and I had tried to manage my expectations beforehand! Also conditions were not perfect at all, and I know that it takes several sessions to really get to know a scope.

By the way, I avoided doing a star test after reading several articles about the pitfalls if star testing apo's! However I did establish that the collimation seemed good. I should add that the build quality is superb, very hefty rotatable focuser, good focus lock (which locks the pinion rather than the tube), and a huge sliding dewshield which stays in place!

So over the next few sessions I will either stick to some proper observing with the scope, or do a head to head with the Tal, which is really the benchmark I am hoping to beat with this scope.

Watch this space!

Nice report! Mars is certainly spectacular at the moment. You have some great planetary scopes there, very interested to see how you get on with the Stella Mira so looking forward to more reports. 👍

That's a phenomenal amount of detail, captured beautifully as always. Just shows what is possible when an experienced observer with a quality instrument observes under a steady sky. Conversley, when an incompetent observer, with an average instrument meets a turbulent sky.......mush....as happened to me last night!

Very nice sketch, an almost identical view to when I sketched it the other day (your sketch is nicer though!) 

I saw it was clear on my drive home but it had clouded over by the time I was ready to observe. Shame because the seeing looked good. I think we may have some clear nights coming up though. 

14 hours ago, dweller25 said:

Great sketch Rob,

Have you tried a neutral density filter with your C8 to try and dim the view down a little ?

It may help with the colour.

I had the same issue when I used a 10” Dob

Thanks for the idea, I do have a ND filter so I will give it a go. 👍 You’ve reminded me that I have a load of colour filters too which I can try too. 

25 minutes ago, Dantooine said:

Well Rob, 

really happy for you. Is it everything I tried to explain it was?

I have never looked back since I got mine. A very special moment opening the box. 
 

i really don’t think better can be bought for the price these are selling at, enjoy 😊

It was a special moment, my first brand new scope in twenty years and a quality piece of engineering that feels special. Looking through the almost invisible lens and down into the blackened and baffled tube is a wonderful sight. Really looking forward to first light. Thanks for the encouragement, your positive comments sealed the deal. 🙂 I’ll probably start a separate thread to share my experiences. 👍 

After waiting two months for a Skywatcher ED100, still no sign of delivery, so I cancelled order and bought one of these beauties. Arrived next day. A very solid and well made piece of kit. Hope it performs as well as it looks. Can't wait to try it out.

23 minutes ago, mikeDnight said:

A lovely sketch Robert. I hope you continue sketching as it makes a great record of your observations that you can look back on for years to come. 

Thanks Mike. I’m really motivated to continue this, inspired in no small part by your excellent drawings and maps. 

1 hour ago, Fraunhoffer said:

Nice sketch. I was thinking of some pre-prepared blanks aswell. 😁. 

Thanks. 

If you still need templates, you're welcome to use mine. They show the following phases - 85%, 90%, 95%, 98% and 100%. I reduce them to about 50cms on to a printed sheet of A4 (50cms circle size seems to be the commonly recommended size).

An impressive rig then! The outer shell is coming through nicely, looking forward to seeing part 2 (if you end up going for more data).

Crikey John, that's a top quality image. Well done! I bet you had fun processing that. Can you say anything about the equipment and exposures?

Edit: Just seen the level of detail you can get from zooming in the full image - extraordinary.

I've been observing for many years but last night was my first attempt to capture the red planet on paper. A nice night too as Mars was very close the the 90% waning moon.The seeing was unfortunately poor, even at the end of the session, but there were brief moments of relative calm which helped tease out some detail, but not the best night. The result over a period of 90 minutes is shown below. Rather underwhelming I know, but a start, and I can only get better I hope!

C8, x200, Seeing: Poor, altitude: 37 degrees max

Observing notes

The main dark feature is Mare Sirenum, it initially started as a dark 'seagull' shape, but it eventually became apparent that the whole lower hemisphere was dark with the seagull shape even darker. Apparently Olympus Mons was also visible but I could not see it. I think I timed it to see one of the most featureless faces of the planet! The polar ice cap is ringed rather than doing a full blow shading with a white patch. Would it be cheating to pre-prepare a coloured template with the ice cap already shown in white and then shade in the dark areas and rub out the light areas during observing? A screen shot from Sky Guide as a comparison (mirrored). For info I only consulted maps/apps only after the session so I was not influenced. Although I have a number of apps and Maps of Mars I found there was no single map that did the job, it was a case of looking at a number of them. Do other people have this problem? What do people use?

Equipment

From previous experience I felt the C8 was the best scope for the job so I put it on my simple non-goto driven CG5 equatorial mount at a height to allow me to sit - I have to say being seated and having the scope tracking made life so much easier and I don't think I could have observed for 90 minutes (on and off) with my usual setup of standing using a non-driven altaz mount!

I also briefly tried the Tal100RS and the 150PL as a comparison. The C8 clearly revealed the most detail of the three but the colour through the TAL was a glorious deep red and still showed some detail - on a night of good seeing I think it could reveal a lot. After observing through the C8 for 90 minutes, Mars seemed white and the red colour was barely apparent!

1 hour ago, Stu said:

Out of interest, how do you calculate that Robert? Or did you find it referenced somewhere?

I was coincidentally reading “Observational Astronomy” this morning and this information appeared in the chapter on Observing Mars. Hope its still relevant  👍

Nice illustration from Stu. Another way to look at it is a feature will be in the same position 37 minutes later each night, so you can concentrate on one feature for a couple of weeks if you are prepared to stay up late! It will take 5.5 weeks for the feature to be back in the same place at the same time.

Never cleaned my RC6 mirror (I've had it around 5 years) but it rarely gets used and is pretty well wrapped. Never cleaned my Heritage 130P mirror (had it around 3 years) but it does get used more often and is more prone to dust and would probably benefit from a light wash to remove dust and grime - which I may attempt soon. Of course the mirror of my 20 year old SCT has never been touched and is as pristine as the day I bought it!  

My first scope as a teenager back in 1980 was a 6" F8 newtonian. What is the best all round scope now for a beginner? I reckon a 6" F8 Dobsonian!

(or possibly an 8" F6 dobsonian)