Whoops Impulse Purchase on Ebay

[SnakeyJ]

Sounds like you got a great deal. When you buy off a seller like that, who is genuine & maybe has to sell due to health issues, that is when you can get a very good deal even if it means feeling sorry you don't think you paid enough for it.

He seemed a very decent chap and at a guess not very long retired. It's sad to have to give up your hobby and sell everything off - and yet you know the day will come for all of us when it all gets too much, lets hope we all get some clear skies and ample opportunity to get out and use of the equipment before hand

I do at least have an address and will write and let him know how I've got first light! Though with only the full moon visible through the clouds at the moment tonight is not looking too promising!

[SnakeyJ]

Given the similarity between this and the Explore Scientific - http://explorescient...s/ar_152mm.html (pointed out by Russel), I sent an e-mail off to ES re availability of their dual speed focuser as an upgrade. I now feel a bit of a numpty for asking as there seems to be rather more difference in design under the hood:

Dear Mr Gully,

thank you very much for your mail. Do you have a problem with the 4"-focusser that is attached to the telescope? Changing the focusser doesn´t make sense: the Bresser Messer AR-150S is a four-lens system - similar to a Petzval-achromat. The two lenses that form the rear objective are attached to the focusser - the telescope would not work if you remove them. A 2" focusser would also not work with your telescope - at f/5 there would be severe vignetting.

If you have a problem with the focuser, please contact the Bresser representative in UK:

Telescope House

Unit 1 Starborough Farm, Starborough Road, Marsh Green

TN85RB Edenbridge, Kent

Tel.: +44-1342-837 098

www.telescopehouse.com

Mit freundlichen Grüßen

Sincerely

Cordialement

Tassilo Bohm

However, aside from my embarassment for asking such a foolish question, this is quite encouraging - The Petzval Achromat design, is supposed to significantly improve/reduce CA (perhaps 30%), making this more akin to an F7 focal length. The design also offers significant field flattening and has received some interest for narrow band widefield imaging, prompting Vixens NA (Neo-Achromat) design.

Whilst I don't expect to have optics near the quality of the Vixen NA's, this does offer some hope for future widefield imaging if I can ever afford a big enough CCD. And any reduction in CA would be most welcome for brighter objects.

Does anyone happen to know of a good guide/link for collimating refractors?

[russ.will]

That is interesting, because it's almost never mentioned on any website. Now you've mentioned it and I can only find mention on APM Telescopes. It would appear to be a feature specific to that model, because the 127s, nor any of the L tube variants are quoted (where they actually tell you) as doublets.

How is the stock focuser by the way? Surely you've poked it out of a window and had a play?

Come to think of it have you fired up the mount? I noted a few people saying the LXD75 was quite noisy at full slew rate, but as you could choose slower slew rates, it could be made quieter.

Sorry for all the questions, but I may have a slightly vested interest in the information.

Russell

[russ.will]

Oops! Wrong link.

Russell

[SnakeyJ]

Russ,

It was the first I'd heard of this asell, despite trawling the web, reading the SON Review and Chris's (Casemonster) review here The APM site is the only one that mentions the 4 lenses - it would be nice to see it up alongside another 5 or 6" achromat to get a better feel and some comparison, maybe at the next star party!

Stock focuser feels solid and smooth and has masses of travel. Though as you guess it hasn't been outside yet, or even had a little look through the window - reputedly these have quite a long cool down, so planning to get out and rectify as soon as conditions improve/permit.

Can't offer any advice on the autostar as this mount is manual only - though they get good reviews other than the noise, which some report as sufficient to keep the neighbours up. But mechanically I think this is a far better made mount than the Synta Skywatcher or Celestron equivalents.

Once I can get outdoors I'll post a proper first light report on this.

BR - Jake

[SnakeyJ]

Oops! Wrong link.

Russell

No probs I found it quickly and was useful to have the comparison - Like the APM site and some of their prices, have you brought anything from them before?

[russ.will]

But mechanically I think this is a far better made mount than the Synta Skywatcher or Celestron equivalents.

That's the impression I'm getting and why the Bressers interest me.

My HEQ5 was staggeringly inaccurate on GOTO until it had basically been completely disassembled, tuned and screwed back together with the care it should have had at source. The tollerances of the drives on my 300p would be hysterical, were it not for the fact they take money off you for it. Then there's the spares backup....

Russell

[russ.will]

No probs I found it quickly and was useful to have the comparison - Like the APM site and some of their prices, have you brought anything from them before?

No, not yet and the current price of the AC127L on Exos 2 Goto on astroshop.eu is giving pause for thought. 127mm F9 and my ES82s should make for a very usable combination.

Russell

[russ.will]

Given that you credited blamed me back in post #27 for something, I've decided to reciprocate.

As of this afternoon, I've splashed 944 Euro on a Bresser AR-127L on EXOS 2 Goto, purely as a result of YOUR positive feedback.

Russell

[SnakeyJ]

Given that you credited blamed me back in post #27 for something, I've decided to reciprocate.

As of this afternoon, I've splashed 944 Euro on a Bresser AR-127L on EXOS 2 Goto, purely as a result of YOUR positive feedback.

Russell

Russ,

Glad to take the credit and help you spend you hard earned cash - 1200/127 is about F9.5, so this should give excellent views with far less CA than my F5 and also be a good deal more tolerant of EPs. Should be great for planetary, doubles and smaller DSOs - there's a useful thread here where its likened to the TAL 125RS (but more readilly available) and it seems John (Moderator) has owned one - though he does seem to have owned just about everything at some point!

The rate I'm going you'll be out getting first light before me as I've seem to have got wrapped up sorting out the SW Explorer 200P with my now peltier cooled Firefly MV mono for a serious attempt on Saturn when the weather allows. The Bresser is back in its box, languishing in the conservatory. I'm waiting for a 2" diagonal and Panaview 32mm to happen my way so I can check it out on home ground.

Did you order from TS and when are you expecting delivery?

Good luck for a quick and safe arrival - Jake

[russ.will]

I didn't say credit! I said BLAME!

However, you're pretty much spot on with my reasoning. At F9.5, CA should be well contolled although your F5 is a Petzval, so it's not quite a straight comparison. The 127L should be slightly better, but your 152 should be a LOT better that a typical 6" achro doublet. Indeed it should be a lot better than the short tube 127s which is just another short tube achro doublet and that lacks the angular resolution advantages the bigger aperture brings.

The real reason I jumped is actually a lot more drawn out than I'm letting on. I dunno why, but a 5" F9-10 is a bit of a classical achro do-it-all that has become unfashionable in the misguided race for short, imaging friendly FLs. These are virtually irrelevant in achro land and yet long achros have dried up, none the less. Bresser (and ES to a lesser degree) seem to have taken up the baton dropped by Meade, run with it and addressed some of the niggles that on-line forumites have been concerned with.

The reason I picked the AR-127L is because is basically the Meade AR5 LXD75 without the shiny screw heads behind the doublet, which seemed to be the main user issue and it carries on the metal, adjustable lens cell of that model.

I'm fore-sworn never to buy another Skywatcher mount, so the EXOS-2 Goto sidesteps that. It's only real internet issue, is easily adjustable worm gears, plus it will natively work with the Southern Stars SkyFi unit I have.

It will however take two weeks to arrive, so I expect a surfeit of clear skies prior to this point. Sshh! Don't tell the cloud master that I have a 300 F5 Dob tucked up and waiting in the mean time.

Expect LOADS o deatiailed pictures, an extensive first light and a subsequent flocking/tuning thread afte the AR-127 arrives.

Russell

Russell

[E621Keith]

Interesting, I didn't know the Bresser version is a 4 element Petzval achromat or that it has a 4" focuser. I just assumed the entire range are regular achromatic doublet. I wonder why they didn't mention it in their marketing literature or sell it under the ES brand.

It's odd they said the rear optical group is attached to the focuser. The two optical groups in Petzval have fixed spacing, so it should be attached ahead of the focuser draw tube rather than inside it. That way, the focal plane is going to be flat and independent of the focuser position and back focus. If the rear group is inside the focuser draw tube itself, it will be a doublet with a doublet flattener, which means you will also get the spacing issues you get with regular flattener.

Can you post a photo of the rear elements from the focuser end with focuser fully retracted and extended?

[SnakeyJ]

Keith,

It is rather intriguing - you would certainly expect Bresser to make a lot more capital from the design if it gave less CA or flatter field advantages.

I shall try and get this out and take some more detailed pics this pm.

It is noted that the SON review and prev threads here and at CN make no mention of a Petzval design or variation.

BR - Jake

[SnakeyJ]

There is very little information/specification online for this model - but I did find an excellent thread on CN, saying that its not a standard Petzval design - but the 4 element design reduces CA to something like a 6" F8.

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/4823893/Main/4818677

worth a read in full if you want more background on this.

[SnakeyJ]

Can you post a photo of the rear elements from the focuser end with focuser fully retracted and extended?

Kieth,

I've added some photos of the focuser fully racked out and in to my Album below. There's also a shot looking through the optical path from the focuser (diagonal removed).

The rear doublet is fixed and does not move with the focuser travel, as you would expect - though the rear doublet cell is fixed to the focuser.

I had a quick look through at the neighbours TV aerial and there was a definite violet CA fringe - though not unexpected at close focus and in full daylight. Not having recently looked through any other fracs, I can't really give an objective comparison on this.

[SnakeyJ]

First light this evening and all is looking very good. Proper first light report to be posted as its own thread, but this scope definitely performs limited only be my current selection of EPs and a poor & slightly wobbly 1.25" diagonal.

To get a comparison I have this setup alongside my 200P, both using similar EPs (Baader Hyperion Clickstop Zoom @ 24mm in the 200P) and an ED 25mm AR152S. Currently trained in on M44 - The Beehive Cluster and some thickening cloud has temporarily halted the comparison. However the refractor is working very well, clear sharp and very smooth focus - though needs a tweak for collimation. I'm definitely getting a brighter views from the 200P given the extra aperture, but lost the chance to swap the EPs around. The refractor definitely has a flatter field and is very sharp. If the cloud passes I hope to try them both on a 32mm Celestron Possl, that I suspect will perform far better on the AR152S.

If conditions do clear I may get a look at the moon and Saturn, though Saturn will not be ideal close to the full moon - but it may give a chance to push up the magnification.

I really do like the mount, very simple but surprising solid and capable even with the legs fully extended on the tripod. Intermittently we are getting a very fresh wind outside (enough that I've taken the dew shield off the 200P), but no problem at all at 30x magnification. The viewing position is quite low for me at 6'2", though seated it would be perfect.

A few minor issues - the DEC flexcon keeps falling off and needs tightening with a pair of pliers. I need to get a flexcon for the RA axis as it's a very long stretch from the EP. One of the finder alignment bolts (nylon) has a stripped thread and will need to be replaced. I do find the finder position a little awkward and have to rotate the diagonal out of the way to use it, but it gives a great view and the illuminated reticule is a very nice luxury. Aside from these teething probs it's looking very good so far.

[Live_Steam_Mad]

I've splashed 944 Euro on a Bresser AR-127L on EXOS 2 Goto

Russell

Hello Russell,

I am interested in your Bresser EXOS 2 Goto mount. Did it come with a tripod with legs of 1.75" outer diameter or 2.00 inch outer diameter? Did it come with Meade brand AutoStar or Meade brand AudioStar or a Bresser branded hand set which looks just like the AutoStar (or AudioStar) ? As it's a Meade Europe (JOC, Bresser) LXD75 as I understand it?

Regards,

Alistair G.

[russ.will]

In order:

2"

Meade Autostar 497

Correct, it is an LXD75, the sole difference being the Bresser badges, which don't extend as far as the handset.

Russell

[JamesF]

I narrowly avoided an ebay impulse purchase this weekend, though it wasn't astronomy-related.

We are doing open days at various local schools at the moment with a view to deciding where our son should go to secondary school next academic year.  Yesterday we visited one where in the physics department they had a compressed air "mortar" for want of a better description.  Basically a length of 22mm copper tube fitted with a schrader valve (car tyre type valve) at one end and a lever-operated tap at the other, feeding a smaller diameter pipe with a hollow paper projectile over the end.  The idea was to pump the 22mm tube up to about 80psi with a footpump, knock the tap open and shoot the dart across the room.  Apparently it works rather well with nerf gun darts and having checked they do fit rather nicely down a 15mm copper tube

My mouse was hovering over the "buy it now" button on a pack of shrader valves for quite some time

James

[SnakeyJ]

That sounds fun James - now we need a 10ltr diving cylinder and a belt fed breach mechanism. Might be bidding against you on the shrader valves. Only issue will be stopping it iceing up at higher rates of fire

[Omnipaulus]

Hi there,

I purchased mine from Amazon. It is enormous; the dear carrier who brought it to me (all credit for them: I bought it a day before, arrived a day after and I not even paid for next day delivery) might ha carried it vertically, which made the whole weight of the telescope to bear upon the focuser; the bit were the eyepiece goes broke into the focused tube; when I looked into it I could see the second doublet attached at the end of the tube as it looked like, and I it seems to have been mentioned, the focused, although the lenses do not move with the focuser. By the way, the holder for the finder was also broken; zero points for quality control. Very annoying, though Amazon says they are sending a replacement straight away. But I believe this is the last time I buy something like this via Amazon ( the item came from Holland) I prefer to pay a bit more and get it from proper sellers.

Cheers,

[SnakeyJ]

It certainly is a beast - annoying damage, but sure amazon will quickly resolve for you. Let us know how first light goes.

typed on my mobile with Tapatalk

[starman1969]

I didn't realise how old this thread was. How is the scope doing?

[SnakeyJ]

To be honest I haven't really used it enough, I took it up to Newbury for a weekend back at the end of May and have used it perhaps 3 times since getting it back.   Though since building my observatory I have really concentrated on imaging with my newt.     It gives a wonderful widefield view with the 32mm Ultima LX and great contrast, though at F5 benefits from a coma corrector for wide visual.   CA looks pretty well controlled visually on all but brightest objects, though have yet to look at Jupiter with this.     The build quality is excellent and the only gripes I would have are the focuser that is gets a little vague towards full extension and the dew shield that is too short - a longer retractable dew shield would have been a big advantage.   Overall I think it's a very nice bit of kit and deserving of some more use.

[rodrigol]

It been a while since this thread was hot...

I decided to order one of these and saw the right numbers in junglezone and the scope arrived today. The chap that delivered it was kind enough to carry it to our kitchen.

Upon opening the boxes everything looked pristine and I was getting quite existed. The size of the scope is quite impressive. Took off the plastic bag around it and my heart stopped when I noticed the front objective cover was badly cracked. It obviously had received quite a powerful blow :-(. But everything else looked ok? Then i checked the focuser. Upon rotating the knobs it felt smooth and then hard... Smooth and then hard. Hmmm. Then i noticed the box stacked behind the focuser in the main carboard. It had a large hole. Oh no. I emptied it's content to find that hard blow during transit had the focuser destroy the finder and the finder bracket... Sad thing. It's going back and I'm getting my money back. Definitely not packed well enough and this was the last one at the price I could afford.. Bad luck. I though hard about keeping the scope but I did not want to take chances after seeing the damage to the objective cover and perhaps also to the focuser, which may be bent and may require a lengthy factory rebuild. Tsk, bad luck, bad luck. Bresser: you have to pack your stuff better!