Bresser achro AR-152S experiences

[JP-Astro]

Please comment on your experience with the short refractor from Bresser, the AR-152S model. The good, the bad, anything really.

Here it is: Bresser AR-152S

I know its most significant drawback, the CO which is a curse of any achro and particularly the short models. I'm not too sensitive to CO, to say the least. Being on a budget I'm going to use it as a general purpose scope, for everything. Once again, I'm fine with the CO.

What I like about it is of course its light gathering power which no one can deny.  I've seen many reports that 6" achro comes close to both 8" SCT and 8" Newt (of course with certain limitations).

I know it's strength is wide field views but I've heard people used them as a high power instrument for planetary observations as well. That's of course again those people who like me are perfectly fine with the CO.

What I'm also interested to know is how good the quality of this achro is. How durable is the focuser? What material is used for the lens cell - is it cheap pot metal or a little better aluminum? Both of these are not good for constant collimation screw adjustments and I wonder how the lens cell holds up in this respect.

[mikeDnight]

I've used many 6" F5/F6 refractors but all have been doublets not quads like the Bresser. The fact that its a quad worries me a little, especially at the low price. Collimation would be more difficult if things went wrong, and if ever used for solar, it would meed a front aperture solar filter or there may be potential damage to the rear elements.

As a specialist rich field refractor,  a 6" short focus frac is a hard act to follow. Stars are pinpoint and dsos appear bright, high contrast and with high definition.  Scopes are very personal things, but for me there's no other scope design that gives rich field views like a 6" short focal length refractor. The two brands that have proved their worth as large aperture RFT's over the years are the SW 150 F5 Star Travel and the 152 F5.9 Star Wave. I'd prefer either over an 8" or even a 10" anything else, other than a larger aperture frac!

[JP-Astro]

Mike - Thanks for q quick reply and to be honest I had similar thoughts on the 4-element achro design which Bresser AR-152S is. However I was thinking more about extra glass of regular quality (not the ED) inserted in the light path. Sort of in a way it defeats the purpose of a simple 2-element achro design which despite its obvious limitations is a tried-and-true formula on its own. Sure the more elements there are the more precision should be applied in setting it up correctly.

[mikeDnight]

When they first came out back in the late 90's, I bought the Helios 6" F8 while three of my friends bought the Helios 6" F5. All four scopes were simply superb as visual deep sky instruments. I bought the F8 version so as to get better colour correction, but in all honesty, the difference between the F8 and F5 was negligible. The F8 was perhaps just a tad better on the Moon and planets but both would play happily at 250X. One evening at my local astro club, one friend brought along his 6" F5, and although there were a great many large reflectors, Schmidt Cassegrains and a Maksutov Newtonian on the field, nothing could compare with the 6" F5 achromat when it came to beautiful star fields and open clusters. Even globulars and galaxies were quite spectacular in the 6". The bridging arm of M51, linking the main galaxy with the satalite galaxy was detectable, as was the spiral structure of M51 itself. All the Messier objects Infact were a pure joy in the 6", so if fuzzies and comets are where your main interests lie, then I doubt you'll be disappointed by a 6" F5 doublet. I'm going to shut up now, as I'm talking myself into buying one!

Edited May 23, 2019 by mikeDnight

[alacant]

 

 

Hi. Built like a tank. Nice flat field and with the f10 front elements, good colour correction. Here's a snap we took, but better for looking through than attached to a camera. HTH.

Edited May 23, 2019 by alacant

[Vondragonnoggin]

I have both the Startravel F/5 (light blue older model) and the Astro-Telescopes branded version of the v.1 F/5.9

The newer version 3 F/5.9’s are much lighter ringing in at 18 lbs for the OTA while the version 1 is 25 lbs. 

 

I bought the older Startravel 150 used recently as it is only 13 lbs for the bare OTA and the particular specimen I have was hand picked out of three of them and has excellent optics. The AT152 F/5.9 is too much for me sometimes with the weight and probably will be sold, but very reluctant to sell as that one takes high power very well. I am mostly using them low power right now with Night Vision eyepieces and narrowband Ha and longpass near IR filters. No CA issues with 610nm, 640nm, and 685nm Longpass or 3nm and 7nm Ha I use with the Night Vision eyepieces of course. 

When I put some regular eyepieces in though, they are surprisingly very solid performers. The short stubby body is great for height swing from horizontal to zenith. Just right for my adjustable chair.

I’m using them on a T-Rex alt-az Mount with Atlas pier extension on an Avalon T-Pod 130 tripod. The mount is way more capacity than the scopes so everything very steady when viewing and it has slo mo handles for easy movement with clutches locked.

I’ve never tried the Bresser petzval achro but haven’t heard any big complaints except that changing the focuser might be difficult as I think I read the rear lens element is built into the focuser. I could be wrong about that though. It should give some advantage theoretically for CA control over a standard doublet.

For regular eyepiece views I use a Baader Semi-Apo filter but I believe a more effective filter would be a 495nm longpass. The 495nm longpass shifts color to yellow on stars and I prefer the more natural look of the semi-apo even if less effective for CA control. UHC, OIII, and Hb narrowband nebula filters should make the CA a non-issue really in viewing nebulae with regular eyepieces.

The semi-apo also has the neodymium element of it that helps with contrast on Jupiter even if some contrast loss from CA because of the short FR.

For 6” F/5 achromats, the Bresser 152S, Skywatcher Startravel 150, Celestron Omni XLT 150R, and older D&G lens built telescopes should all give some good performance for very reasonable prices. The longer Explore Scientific AR152 F/6.5 and the KUO built versions of the F/5.9 (Altair Astro, Astro-Telescopes, Canadian Telescopes, etc) are both pretty great for cost/performance ratio and probably a little more capable of higher powers with clean views than the unfiltered F/5 offerings, but filters like a minus violet or 495nm longpass or even the semi-apo (or just the Baader Fringe Killer by itself) should help you go higher powers with cleaner view even on the F/5’s.

I have a mak 150 also and usually pick that one if primary targets are going to be Lunar and planetary, but if I have one of the 6” achros out for viewing anyway, I will still go for just about any object I think it capable of reaching if the atmospheric conditions are good. I just really like the refractor view and steadiness I get with them (and the mak when thermally equalized). The widefield view is amazing with low power eyepieces too. Good Milky Way sweeper.

[xtreemchaos]

a Few year back "maybe 10" i had the old 152s  it was a nice scope but a tad on the heavy side. just outa interest  is this new one all elements in the objective or with two in the draw tube ?. charl. edit ive just read the post above, that will teach me to look before i leap 😀

Edited May 23, 2019 by xtreemchaos

[Vondragonnoggin]

You might be able to find reviews of performance by also searching for Astrozap 6” F/5 petzval achromat.

 

Astrozap used to sell the same telescopes as the Bresser models for both 152S and 152L as well as both 127S and 127L.

[alacant]

1 minute ago, xtreemchaos said:

is this new one all elements in the objective or with two in the draw tube ?

Hi. Two groups of 2. The eyepiece end carries 2 elements in the -long- draw tube.

 

[John]

I've owned a few of the Chinese F/8 6 inch achromats over the years. They show quite enough CA for my eye so I've avoided the F/5's and the Petzval versions. The other issue with these Chinese achromats is spherical aberration (SA), displaying either under or over correction. This has the effect of limiting the sharpness and contrast of the image at higher powers and resulted in all the scopes of this type that I've owned (4 Syntas and a Meade at last count) lacking in image quality at much over 200x.

For me, SA is just as bad if not worse than CA in limiting scope performance.

I managed to improve the performance of these F/8 achros substantially by using a Chromacor CA and SA corrector. These somewhat exotic devices are not filters but optical correctors and they do a remarkable job in bringing the wavelengths of light to focus at much closer to the same point - similar to the performance that a decent ED doublet achieves in fact. Correctly matched to the objective the Chromacor will also correct SA and when fitted correctly these devices revealed to me the extent to which these aberations impact image quality.

Eventually I decided to move to using ED doublets and thats where I'm at now. If I go for another 6 inch refractor it would be an ED doublet.

For what it's worth I've read many reliable reports that the 152mm F/5.9 achromats such as the Altair Starwave 152 (link below) deliver CA correction as good as the stondard Chinese F/8 achros and have better figured objectives as well so negligable SA:

https://www.altairastro.com/starwave-152mm-f5.9-achromat-refractor-telescope-with-3-crayford-focuser.html

 

[xtreemchaos]

thanks, so still not good for solar without the huge cost of a front mounted ERF.

[JP-Astro]

2 hours ago, John said:

... For what it's worth I've read many reliable reports that the 152mm F/5.9 achromats such as the Altair Starwave 152 (link below) deliver CA correction as good as the stondard Chinese F/8 achros and have better figured objectives as well so negligable SA:

https://www.altairastro.com/starwave-152mm-f5.9-achromat-refractor-telescope-with-3-crayford-focuser.html

 

Looks like it's the same scope as the TS Optics F/5.9 only re-branded:

TS F/5.9

[Vondragonnoggin]

3 minutes ago, JP-Astro said:

Looks like it's the same scope as the TS Optics F/5.9 only re-branded:

TS F/5.9

Yes. All the F/5.9 scopes (TS, Altair, Astro-Telescopes, Canadian Telescopes, and probably a few others) are Kunming United Optics manufactured and just varying differences in focusers and finish. Some have 3” focusers and some 2.5” focusers. These are now at version 3 of production and they substantially dropped some weight from original 25 lb OTA to 18 lbs for version 3 production.

[Vondragonnoggin]

An older review of the Astro-Telescopes version 1 F/5.9 vs Explore Scientific AR152 F/6.5

https://www.scopereviews.com/page1y.html

[Vondragonnoggin]

Some discussions on the Astrozap 152S and 152L petzval (Same as Bresser)

 

https://www.cloudynights.com/topic/173485-astrozaps-5-and-6-achros-any-good/

 

and the SGL Member review for the F/5 petzval 

 

Edited May 23, 2019 by Vondragonnoggin