I'm refractor-ing it - opinions on this frac please.

[emadmoussa]

Hola,

I've got many reasons to move back to a large aperture refractor, and ridding myself of reflectors. Long story.

My main target was the Explore Scientific 152mm f/6.5. Unfortunately with the shipping costs from the US it'll cost a fortune.

So, I managed to find a German supplier for the Bresser Messier 152mm f/7.5. It was second on my list anyway. Before anybody asks, It's mainly for visual as well as lunar and a bit of planetary imaging. I understand the CA issues, which I'm not very worried about since you can always correct them either in image post processing or through filters.

I'd appreciate your opinions on the product below:

Bresser Telescope AC 152/760 Messier

Specifications:

Optics

Type Refractor Type of build Achromat Aperture (mm) 152 Focal length (mm) 760 Aperture ratio 5 Resolving capacity 0,76 Limit value (mag) 12,7 Light gathering capacity 470 Max. useful magnification 300 Tube weight (kg) 10,6

Eyepiece holder

Type of build Gear rack Connection ( to eyepiece) 2

Mount

Mounting type no mount GoTo control no Type of build OTA Tracking no

Included accessories

1.25'' eyepieces SP 26mm Camera adaptor T2 Finder scope 8x50 Deviating optics 1.25", 90° star diagonal Miscellaneous Tube clamps

General

Series Messier Special recommendation yes

Area of application

Moon & Planets yes Nebulae & galaxies yes Nature observation yes Astrophotography yes Sun not recommended (Only with appropriate Sun filter)

recommended for

Beginners no Advanced yes Experienced amateurs yes

[John]

Moon and planets - yes but expect loads of CA - it's an F/5 achro. The Skywatcher Startravel 150 F/5 would be less expensive and do the same job:

http://www.harrisontelescopes.co.uk/acatalog/SkyWatcher_StarTravel_150_Refractor_Optical_Tube_Assembly.html

I'd really not pay lots for a 6" achro though. They can be bought pretty cheaply used and you don't want to be the one to take the depreciation !.

Heres an example - I used to own the scope below. I bought it for £125, sold it for that and it's now just been sold for the same. Basically this is the more or less the same as the Bresser scope above but in F/8 format:

http://www.astrobuysell.com/uk/propview.php?view=67187

[emadmoussa]

Oh, forgot to mention it's just under £400

I see your point, John. I am not taking the plunge for a couple of weeks at least. Meanwhile I am keeping my eyes open for a second hand one, or if I am lucky I'll find a C8 for a similar price.

I saw the one on Astro buy and sell. Would've grabbed it if it hadn't been sold already.

[SnakeyJ]

Just so happens I have one, though only had a few little peeks with it and waiting for my 2" diagonal before I post a proper first light report.

Its an unusual design with 4 elements (objective air space doublet and a seconday doublet mounted before the 4" focuser), similar to a Petzval design. Although rated F5, the design is meant to improve CA to that of an F8 achromat. The design is similar to the Vixen NPLs which were marketed for visual and narrowband imaging - though at around half the price the quality is not going to be quite as good. Full thread below.

There's very little info posted on this scope, but a good review on SGL and some interesting comment at CN

I will be taking it up to Newbury on May bank holiday weekend if you wanted a proper look.

BR - Jake

[ollypenrice]

Totally agree with John. I have the slower version with 1200mm FL which I've never bothered to sell because selling it would consume the value of the scope! Well, it would consume the commercial value. It is, in fact, a scope worth looking through and no mistake. It never gets used, which is a shame, but it's worth the price of a decent second hand eyepiece so I wouldn't want to buy a new one. Are you sure you want the F5? I think the rather slower one is much better.

Olly

[emadmoussa]

Mmm...I am having second thoughts right now.

Jake, thanks for the review. I have to say one of the readons Im ditching the 200P is the size. This frac is larger than I thought...how qbout tge weight and handling?

Olly, most of my astro work will be for AP. So, in terms of aperture I am kind of downsizing. I still would like a scope with a considetable amount of power. What's the version you've got?

[emadmoussa]

I meant for visual..

[SnakeyJ]

Jake, thanks for the review. I have to say one of the readons Im ditching the 200P is the size. This frac is larger than I thought...how qbout tge weight and handling?

Olly, most of my astro work will be for AP. So, in terms of aperture I am kind of downsizing. I still would like a scope with a considetable amount of power. What's the version you've got?

Its about 10kg with the supplied diagonal and 106cms from dew shield to diagonal with the draw tube retracted - 13cms longer than my 200P!

This is definitely a visual rig, most suitable for wide angle/deep sky, almost the antithesis of the C8/C9.25. Imaging wise probably not much cop for anything other than narrow band - though I will take be having a go at some point.

Most of the deep sky imaging seems to be small fast APO refractors for widefield, though I have seen some excellent images from the big newts (with diffraction spikes) and the Mak Newts (but these are big and heavy). For narrower field the SCTs are capable, but rather slower.

This is all Olly's forte really, but will depend entirely on what targets you intend to image - Though looking at some of the fantastic images posted, I would have thought the ED80 covers a lot of the range.

On a separate tack I saw you were looking for a C8/C9.25 in the classified section. I did see a great offer on the C11s earlier today at 365 - http://www.365astronomy.com/celestron-c11sgt-xlt-computerised-goto-telescope-p-3361.html?gclid=COzu4u_Lu7YCFcLHtAodRSYANw . As this is selling under £ 1500 with the CG-5GT mount and the OTAs usually retail around this mark, I assume that the OTA itself is lower quality. Still pretty sure it would make a great planetary imager for under a grand if you sold the goto mount straight on.

[David Smith]

Think there is a C8 ota for sale in the classifieds at the moment...

http://stargazerslou...637-everything/

[Bart]

Have a look at the for sale section in the Irish forum (IFAS) here, I think it might be what you're looking for, an ES, you guys might be able to arrange a courier.

http://www.irishastronomy.org/index.php?option=com_kunena&func=view&catid=17&id=95671&Itemid=40

Barry

[Bart]

For some reason, can't edit my last topic. Anyway just noticed you're looking for 150mm and this is 127mm. May be worth a look anyway.

Barry

[emadmoussa]

For some reason, can't edit my last topic. Anyway just noticed you're looking for 150mm and this is 127mm. May be worth a look anyway.

Barry

I would consider a 127mm, but the one on that forum is way out of my price range.

[emadmoussa]

I'm not quite sure about this model. Does anybody know?

http://www.astrobuysell.com/uk/propview.php?view=66558

[emadmoussa]

Its about 10kg with the supplied diagonal and 106cms from dew shield to diagonal with the draw tube retracted - 13cms longer than my 200P!

This is definitely a visual rig, most suitable for wide angle/deep sky, almost the antithesis of the C8/C9.25. Imaging wise probably not much cop for anything other than narrow band - though I will take be having a go at some point.

Most of the deep sky imaging seems to be small fast APO refractors for widefield, though I have seen some excellent images from the big newts (with diffraction spikes) and the Mak Newts (but these are big and heavy). For narrower field the SCTs are capable, but rather slower.

This is all Olly's forte really, but will depend entirely on what targets you intend to image - Though looking at some of the fantastic images posted, I would have thought the ED80 covers a lot of the range.

On a separate tack I saw you were looking for a C8/C9.25 in the classified section. I did see a great offer on the C11s earlier today at 365 - http://www.365astron...CFcLHtAodRSYANw . As this is selling under £ 1500 with the CG-5GT mount and the OTAs usually retail around this mark, I assume that the OTA itself is lower quality. Still pretty sure it would make a great planetary imager for under a grand if you sold the goto mount straight on.

Mmm..but I assume it's easier to handle and mount than the 200P...or at least less awkward?

Oh, sorry, I should say that my budge is around £400...

[SnakeyJ]

Mmm..but I assume it's easier to handle and mount than the 200P...or at least less awkward?

Oh, sorry, I should say that my budge is around £400...

I've only had about 2hrs actual viewing time, split between using it on the LDX75 (manual) and HEQ5 Pro, so not a massive amount of hand on to be objective - but I do really enjoy using it so far and have some excellent views on M3, M13 and M42 using the hyperion clickstop and my Ostara ED 22mm using the cheap and nasty supplied 1.25 diag. I have tried it with my 2" 25mm super possl (which I had to use straight through and slip it out a litle to achieve focus as no 2" diag til the end of the month) - but this gave the best widefield so far and fantastic view of Orions sword area. I was sat on my observing stool at lowest postiion, which was actually quite comfortable for this, but no chance using it near zenith without the diagonal. Also haven't had a chance to use with the coma corrector yet, which at F5 may be needed for the wide field.

The quality of the OTA, rings, focuser and finder is really good (bordering excellent) for the price and the 8x50 illuminated finder is an absolute joy to use - once I had adjusted focus for the reticule and objective. Some comment that the dew shield is a little too short, though easilly rectified if needed - my dust cap is a little sticky and getting it off the dew shield without disturbing the mount is a fiddle - though an easy fix. Overall balance is very good - in most achromats all the weight is at the front end in the flint and crown doublet, but in the AR-152S the two doublets and 4" focuser seem to conteract and balance out nicely.

I haven't had a look at the moon, Jupiter or Saturn in this to date - I would expect to see a lot of CA on the moon and Jupiter, but probably less problematic on dimmer Saturn. There are good fringe killer filters available, though not sure how much this will worry me.

What I need is a decent night to get both scopes out side by side and do some proper comparison, but once the diagonal and those fabled clear nights are here I shall be doing exactly that.

[emadmoussa]

I've only had about 2hrs actual viewing time, split between using it on the LDX75 (manual) and HEQ5 Pro, so not a massive amount of hand on to be objective - but I do really enjoy using it so far and have some excellent views on M3, M13 and M42 using the hyperion clickstop and my Ostara ED 22mm using the cheap and nasty supplied 1.25 diag. I have tried it with my 2" 25mm super possl (which I had to use straight through and slip it out a litle to achieve focus as no 2" diag til the end of the month) - but this gave the best widefield so far and fantastic view of Orions sword area. I was sat on my observing stool at lowest postiion, which was actually quite comfortable for this, but no chance using it near zenith without the diagonal. Also haven't had a chance to use with the coma corrector yet, which at F5 may be needed for the wide field.

The quality of the OTA, rings, focuser and finder is really good (bordering excellent) for the price and the 8x50 illuminated finder is an absolute joy to use - once I had adjusted focus for the reticule and objective. Some comment that the dew shield is a little too short, though easilly rectified if needed - my dust cap is a little sticky and getting it off the dew shield without disturbing the mount is a fiddle - though an easy fix. Overall balance is very good - in most achromats all the weight is at the front end in the flint and crown doublet, but in the AR-152S the two doublets and 4" focuser seem to conteract and balance out nicely.

I haven't had a look at the moon, Jupiter or Saturn in this to date - I would expect to see a lot of CA on the moon and Jupiter, but probably less problematic on dimmer Saturn. There are good fringe killer filters available, though not sure how much this will worry me.

What I need is a decent night to get both scopes out side by side and do some proper comparison, but once the diagonal and those fabled clear nights are here I shall be doing exactly that.

Thanks for the brief preview, Jake.

Fingers crossed I'll find a similar item second hand. A lot of people ask me why I want to replace my 200P with a 6" frac.. If you don't feel comfortable using the reflector and enjoy the hobby then what's the point?!! Call me a wimp, but I always found pointing and finding a target with reflector an awkward task. With refractors on the other hand, I just go smack on for the right target. I don't know why, I think my brain has an anti-reflector filters fitted into it

Usually my asto-photography has a different gear - the 80ED/ST80 gang. But as you know, if you don't have an obsy setting up and disassembling the AP gear is quite time consuming...if not quite boring at times. It's usually brilliant (NOT)having set up everything, turned on the machines..sat down...and bang...CLOUDS!!! So, it'll be nice having a frac for visual (mainly)...no wires...no nothing.

My only concern is undermining any potential planetary imaging if I go frac!

[SnakeyJ]

Thanks for the brief preview, Jake.

Fingers crossed I'll find a similar item second hand. A lot of people ask me why I want to replace my 200P with a 6" frac.. If you don't feel comfortable using the reflector and enjoy the hobby then what's the point?!! Call me a wimp, but I always found pointing and finding a target with reflector an awkward task. With refractors on the other hand, I just go smack on for the right target. I don't know why, I think my brain has an anti-reflector filters fitted into it

Usually my asto-photography has a different gear - the 80ED/ST80 gang. But as you know, if you don't have an obsy setting up and disassembling the AP gear is quite time consuming...if not quite boring at times. It's usually brilliant (NOT)having set up everything, turned on the machines..sat down...and bang...CLOUDS!!! So, it'll be nice having a frac for visual (mainly)...no wires...no nothing.

My only concern is undermining any potential planetary imaging if I go frac!

Fancy a trip over to take a look? Bembridge and the IOW ferry make this a bit of a hassle, but could always come and pick you up from the hover or fast cat. Otherwise, I shall take this rig (with the HEQ5) up to a little camp site to the south of Newbury for May Bank Holiday w/end - no idea what the weather holds in store, but it might be a more convenient to have a look.

The other thing that did occur to me is that with the NEQ6 you should be able to piggy back mount the ED80 directly above a large frac, giving visual and ap - though weight wise this would be bulky and probably better suited for a permanent obs setup as you'd have to setup and play to eliminate any cone error/alignment issues.

If the weather clears I'll try and get out and do some lunar obs and imaging, just to see how this all plays.

[emadmoussa]

Fancy a trip over to take a look? Bembridge and the IOW ferry make this a bit of a hassle, but could always come and pick you up from the hover or fast cat. Otherwise, I shall take this rig (with the HEQ5) up to a little camp site to the south of Newbury for May Bank Holiday w/end - no idea what the weather holds in store, but it might be a more convenient to have a look.

The other thing that did occur to me is that with the NEQ6 you should be able to piggy back mount the ED80 directly above a large frac, giving visual and ap - though weight wise this would be bulky and probably better suited for a permanent obs setup as you'd have to setup and play to eliminate any cone error/alignment issues.

If the weather clears I'll try and get out and do some lunar obs and imaging, just to see how this all plays.

Thanks for the offer, Jake. It's tempting, but a bit of a hassle especially for some one who doesn't drive

Yep, looking forward to your imaging the moon.

[emadmoussa]

I've come across the Astro-Professional 152mm refractor...it seems like a high end achromatic frac, but I guess still over-priced. Have a look:

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p2229_Individual-152-900mm-Gro-feldrefraktor---3--Crayford-Auszug.html

Very nice scope though

[SnakeyJ]

Looks beautifully made, and slightly longer focal length 900mm as opposed to 760 giving F5.9 - quite expensive given that this is just the OTA and tube rings, but the 3" dual speed focuser looks very useful and nicely engineered. I also like the idea of the retracting dew shield.

Interesting thread on CN http://www.cloudynights.com/ubbthreads/showflat.php/Number/5180541 claiming this is identical to the CT 152/900 and is actually made for both companies by United Optics http://www.united-optics.com/Products/Telescope/Achromatic_Telescope/152mm_F-5.9.html (Kunming, China).

Not sure on the merits of the O'Hara K9/KV doublet compared against the 4 piece pretzval design in the AR-152S - but some very nice attributed images on astrobin (mostly narrow band and all DSO): http://www.astrobin.com/gear/202/

[emadmoussa]

Looks beautifully made, and slightly longer focal length 900mm as opposed to 760 giving F5.9 - quite expensive given that this is just the OTA and tube rings, but the 3" dual speed focuser looks very useful and nicely engineered. I also like the idea of the retracting dew shield.

Interesting thread on CN http://www.cloudynig.../Number/5180541 claiming this is identical to the CT 152/900 and is actually made for both companies by United Optics http://www.united-op...52mm_F-5.9.html (Kunming, China).

Not sure on the merits of the O'Hara K9/KV doublet compared against the 4 piece pretzval design in the AR-152S - but some very nice attributed images on astrobin (mostly narrow band and all DSO): http://www.astrobin.com/gear/202/

Wow! These seem identical:

1)Individual Rich Field Refractor 152/900mm - Aperture F/5,9 - with high class 3" focuser

2) 152mm F-5.9

Yep, like you say, Jake, the German Teleskop Service one is over priced. I contacted the Chinese manufacturers in the hope of finding a better deal 'cause this scope is becoming a good candidate for my upgrade.