Results 1 to 9 of 9
Like Tree1Likes
  • 1 Post By raico

Thread: Newbie- need a barlow? (or seben ebay)

  1. #1
    raico's Avatar
    raico is offline Junior Member
    Points: 6,773, Level: 57
    Level completed: 12%, Points required for next Level: 177
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Oct 2009
    Location
    Tenerife, Canary Islands
    Posts
    5
    Points
    6,773
    Level
    57
    Thanks
    5
    Thanked 0x 0 Posts

    Default Newbie- need a barlow? (or seben ebay)



    Hi
    yep, another newbie post.. I just bought a 2nd hand Konus 500 Newton 114mm (4.5"). i checked some reviews and this thing is meant to be real good for beginners..i got really excited since living on tenerife (canary islands) is like living next to the observatory in hawaii in terms of viewing conditions!

    Anyway, i set the konus up clumsily and figured Jupiter would be a winner for first time viewing. After several attempts and finally finding this planet I tried the 2 plössl 10 and 17mm eyepieces. That was very dissapointing... one showed Jupiter as a bright green dot and the other slightly larger but white.

    I did some research and found these eyepieces combined with my konus 500 only give x30 and x50 magnification compared to the x228 capacity of this scope.. So i guess i need a barlow lens but after my research only found x2 barlows.. that means x100 magnification if im not mistaken. Ive read of people obtaining the max magnification (x245) for these sort of scopes. Am i missing out on something?

    Also i keep stumbling across these X2 barlows 1.25" for a very modest price on ebay from a manufacturer called "Seben" from germany though i have not yet found a review for them.. what can anyone recommend??
    Most appreciated!!
    Last edited by raico; 10-19-2009 at 10:39 PM. Reason: forgot name

  2. #2
    WWPierre's Avatar
    WWPierre is offline HYPER GIANT
    Points: 64,445, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    10 Days registered3 Years + Achievement400+ Posts AchievementGhost Achievement! Averaging 5+ posts a day!1000 Days+ Registered Achievement!
    Join Date
    Jun 2009
    Location
    Squamish B.C.
    Posts
    6,948
    Points
    64,445
    Level
    100
    Thanks
    1,095
    Thanked 2,953x 1,808 Posts

    Default

    Hi Raico, welcome to the forum. I bought a Seben barlow on E-bay, and it works. The only test I have done is to compare my zoom barlowed and set at 24mm (54x) to my no-name 10mm (65x). These old eyes couldn't see any difference but the "test" was far from scientific. I am waiting for the opportunity to compare it side-by-side with another barlow.

    This company's quality rep is spotty, according to the forums, but the barlow is cheap, and it does work.

    Have you done a star test to check your collimation? My scope is only slightly bigger than yours and I can see cloud bands on Jupiter, even though seeing is not the best here. (at higher mags the rim of the planet is distorted by heat waves)
    Last edited by WWPierre; 10-20-2009 at 04:57 AM.
    Meade 16" LightBridge; Celestron G-8N Bird-Jones/motorized EQ5;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    127 Mak/go-to EQ5; Burgess 127f8 refractor; Sky-Watcher 5" F/5 collapsible dob; 90mm Mak/motorized EQ2; Royal Astro 76/910-GEM; Meade 60x700 refractor/alt/az; Zhumell 25x100 Coin Ops; GalilleoScope. Celestron 8mm-24mm zoom; lots of fixed EPs,some good, some..not so much. A small collection of surveying instruments; a forest of tripods; Canon Rebel Xti. Confirmed gadget junkie; Custodian of the Magnetic North Pole (Send $1.00 to Pierre each time you use a compass.)
    49-41-37.03N 123-09-29.61W Calculated magnetic declination: 17° 39' East

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    We have been broadcasting our presence to the Universe for 100 years now. If there is a detachment of Galactic Pest Control within 100 light years, they are already on the way.

  3. The Following User Says Thank You to WWPierre For This Useful Post:

    raico (10-21-2009)

  4. #3
    raico's Avatar
    raico is offline Junior Member
    Points: 6,773, Level: 57
    Level completed: 12%, Points required for next Level: 177
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Oct 2009
    Location
    Tenerife, Canary Islands
    Posts
    5
    Points
    6,773
    Level
    57
    Thanks
    5
    Thanked 0x 0 Posts

    Default

    Hi pierre,
    thanks for your reply. The seben sounds good enough for me. after some more research that is pretty much what i found aswell about seben. that confirmed their reputation.

    I havent done a star test to check for collimation yet as i simply dont know what that is. I will doing some research on that.

    On the magnification issue, are you acheiving highest magnification with your celestron 8mm-24mm zoom combined with the 2x barlow? Im trying to aim for the x228 magnification that apparently is possible with my scope. Im guessing i can only acheive x100 combining the 10mm plössl with a seben x2 barlow once i get my hands on one..

    How could i acheive the x228 magnification.. im dying to see some exciting stuff!!
    thanks again

  5. #4
    GriffinBF's Avatar
    GriffinBF is offline Super Moderator
    Points: 37,400, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 7.0%
    Achievements:
    Got three Friends20+ Friends Achievement!First 1000 Experience Points5+ Referrals Achievement!100+ Threads Achievement!
    Join Date
    Feb 2009
    Location
    Alberta, Canada
    Posts
    6,717
    Points
    37,400
    Level
    100
    Thanks
    1,757
    Thanked 2,757x 1,841 Posts

    Default

    Hi raico.. no opinion on the barlow, just wanted to say Welcome aboard!

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  6. The Following User Says Thank You to GriffinBF For This Useful Post:

    raico (10-21-2009)

  7. #5
    sxinias's Avatar
    sxinias is offline Super Moderator
    Points: 322,851, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 39.0%
    Achievements:
    Got three Friends20+ Friends Achievement!First 1000 Experience Points5+ Referrals Achievement!100+ Threads Achievement!
    Join Date
    Nov 2008
    Location
    Marathon Greece summer Tampa Florida winter
    Posts
    17,799
    Points
    322,851
    Level
    100
    Thanks
    4,582
    Thanked 10,190x 6,474 Posts
    Blog Entries
    4

    Default

    Welcome to the Astronomy Forum and to astronomy.

    Sorry that you could not see details of Jupiter. Under good viewing conditions you should be able to see two dark cloud bands. Under bad conditions, a white, swirling, blob.

    Last night, I took my C6S out just after sunset. Jupiter was the only object easily visible in the sky but some of the brighter stars were barely visible. I aimed my scope on jupiter and the seeing was super; the best that I've ever seen the planet. All my eyepieces were usable but the contrast was low because it was not yet dark. Self, I said to myself, its going to be a great night so off to finish some chores I had to do. Two hours later when I went back out, I focused on Jupiter once again in anticipating great views with lots of contrast of Jupiter now that the sky was dark. Wrong. The seeing had severly deteriorated. Jupiter was a swirling blob with details popping in and out but mostly out. Packed it up, fired up the labtop and read the postings on Astronomy Forum.

    You are correct, the maximum theoretical magnification is 228x for a 114mm telescope. However, rarely will viewing conditions exist that will allow you to achieve this amount of magnification; somewhere around 125-150x will be about the most you can hope for under most viewing conditions. A 2x power barlow will take you up to 100x which will be usable most of the time and give you a nice viewing range with the two eyepieces you have.

    You may want to do a star test to check the collimation of your scope. Collimation, not bad viewing conditions, could be your problem.

    With inexpensive equipment, I've learned over time one can run accross a jewel from time to time but generally you get what you pay for. Go ahead and try the Seben barlow. If it works for you, then you got a bargain. If it dosen't, you will not be out much money and the barlow should still work for the moon. There is a cheap moon filter on eBay touted for 1.25 inch eyepieces. I purchased it but it is a tat too large to screw into the base of a 1.25 eyepiece. Unfortunately, its not big enough to use as a paper weight.

    Again, welcome to the astronomy forum and clear skies.
    SXINIAS

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.



    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ZEQ25 mount;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    SynScan AZ
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Mount;

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ST-80A 80mm Refractor (OTA); Meade
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    203mm SCT (OTA);
    Meade DS2090AT 90mm Refractor; Meade 2045LX3 102mm SCT;

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    4 SE 102mm MAK; Celestron Advanced Series C6S (XLT) 150mm SCT
    with an iOptron GOTO Drive

    My Photos:
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  8. The Following User Says Thank You to sxinias For This Useful Post:

    raico (10-21-2009)

  9. #6
    WWPierre's Avatar
    WWPierre is offline HYPER GIANT
    Points: 64,445, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    10 Days registered3 Years + Achievement400+ Posts AchievementGhost Achievement! Averaging 5+ posts a day!1000 Days+ Registered Achievement!
    Join Date
    Jun 2009
    Location
    Squamish B.C.
    Posts
    6,948
    Points
    64,445
    Level
    100
    Thanks
    1,095
    Thanked 2,953x 1,808 Posts

    Default

    Raico. get a bright star in your FOV. Defocus it until it looks like a donut, or a washer, I suppose. If it is perfectly symmetrical, you are collimated. If not, go here and find the pattern you see.
    Meade 16" LightBridge; Celestron G-8N Bird-Jones/motorized EQ5;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    127 Mak/go-to EQ5; Burgess 127f8 refractor; Sky-Watcher 5" F/5 collapsible dob; 90mm Mak/motorized EQ2; Royal Astro 76/910-GEM; Meade 60x700 refractor/alt/az; Zhumell 25x100 Coin Ops; GalilleoScope. Celestron 8mm-24mm zoom; lots of fixed EPs,some good, some..not so much. A small collection of surveying instruments; a forest of tripods; Canon Rebel Xti. Confirmed gadget junkie; Custodian of the Magnetic North Pole (Send $1.00 to Pierre each time you use a compass.)
    49-41-37.03N 123-09-29.61W Calculated magnetic declination: 17° 39' East

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    We have been broadcasting our presence to the Universe for 100 years now. If there is a detachment of Galactic Pest Control within 100 light years, they are already on the way.

  10. The Following 2 Users Say Thank You to WWPierre For This Useful Post:

    Harllequin (10-27-2009),raico (10-21-2009)

  11. #7
    ebusinesstutor's Avatar
    ebusinesstutor is offline Bright Giants
    Points: 8,910, Level: 65
    Level completed: 54%, Points required for next Level: 140
    Overall activity: 0%
    Achievements:
    10 Days registered200+ Posts Achievement!365 Days+ Registered Achievement!First 1000 Experience Points750 Days+ Registered Achievement!
    Join Date
    Jul 2009
    Location
    Canada
    Posts
    310
    Points
    8,910
    Level
    65
    Thanks
    126
    Thanked 159x 80 Posts

    Default

    If you are looking for inexpensive barlows with a better reputation than Seben, try Owl Astronomy.

    I have a 2x barlow from them and it seems to work well. They also carry a 3x barlow. Cost is only about $19-$22.

  12. The Following 2 Users Say Thank You to ebusinesstutor For This Useful Post:

    raico (10-21-2009),sxinias (10-20-2009)

  13. #8
    raico's Avatar
    raico is offline Junior Member
    Points: 6,773, Level: 57
    Level completed: 12%, Points required for next Level: 177
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Oct 2009
    Location
    Tenerife, Canary Islands
    Posts
    5
    Points
    6,773
    Level
    57
    Thanks
    5
    Thanked 0x 0 Posts

    Default

    Thanks for the very warm welcome. I havent been able to put all this stuff in practice since im up to my neck at work at the moment... :-(

    From what i remember seeing, the collimation aint great. i must check when im free

    thanks again, very helpful!

  14. #9
    raico's Avatar
    raico is offline Junior Member
    Points: 6,773, Level: 57
    Level completed: 12%, Points required for next Level: 177
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Oct 2009
    Location
    Tenerife, Canary Islands
    Posts
    5
    Points
    6,773
    Level
    57
    Thanks
    5
    Thanked 0x 0 Posts

    Default

    Wow! just thought: "sod the work for a minute, im itching to check the collimation on the scope!.."
    After taking ages to find Jupiter again to my delight the collimation is perfect! nice symetrical doughnut!!

    Still looking for a x3 barlow instead of x2. The owl optics looks like a good insider tip, however i dont see any shipping options to Spain. Will send them an email..

    thanks a million!!
    Moon dancer likes this.

 

 

Similar Threads

  1. Newbie having trouble with a barlow lens
    By Eden in forum Telescope Eyepieces Forum
    Replies: 5
    Last Post: 03-09-2010, 07:10 PM
  2. Seben Barlow Comparison
    By WWPierre in forum Telescope Eyepieces Forum
    Replies: 4
    Last Post: 10-26-2009, 05:34 AM
  3. 5x Tele Vue Barlow for sale on eBay
    By Chris Taylor in forum UK Astronomy Forum
    Replies: 0
    Last Post: 12-14-2005, 06:18 PM
  4. re:newbie barlow question.
    By IWJPoel in forum Amateur Astronomy Forum
    Replies: 0
    Last Post: 10-18-2003, 12:53 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 10:52 AM.