7 replies to this topic

[Kim2010]

So I can easily see a sliver of black, ie split, 52 Orionis with my C8, but now I am using my 5" TS 125mm apo, and I can't seem to get a clean split, but just a peanut shape. Is this expected of a 5" apo vs the C8? I even used a ridiculous 2.3mm EP and no clean split on the 5". I will try again later and see if it was seeing-related.

 

Also, when you say pinpoint stars, I am seeing pinpoint stars but not on bright stars which show as "balls". Is this normal as well?

[hasebergen]

Hi

 

it should be work easyly.

 

I´ve splittet 52 Ori with an 110 years old 122mm refractor with 209/292x and also with a also ~110 years old british 125/2000 refractor with 240power.

 

If it doesnt work, one the one hand: poor seeing or on the other hand: your telescope is defective ...

 

regards hannes

[Kim2010]

Hi

 

it should be work easyly.

 

I´ve splittet 52 Ori with an 110 years old 122mm refractor with 209/292x and also with a also ~110 years old british 125/2000 refractor with 240power.

 

If it doesnt work, one the one hand: poor seeing or on the other hand: your telescope is defective ...

 

regards hannes

 

I'll try again, so with 195x should I see a clean black space split?

[Redbetter]

Looks like it is a little less than 1" separation at this time, so very much seeing dependent with a 5".   The 8" has considerably better resolution at this level.

 

My 125 EDL doublet takes considerable time to thermally equilibrate if the outdoor temp is significantly lower than indoors (e.g. 25+ deg F delta.)  It produces some poor images early on and sharpens noticeably as the optic cools.  The 10" Dob with a fan is probably quicker or similar from what I have seen, although the Dob benefits from greater potential resolution, so any time based resolution comparison is skewed.  

 

I wouldn't expect much temp. difference at night in the Philippines, from my limited time there (Cebu and Bohol), but specific circumstances could vary considerably.

[Bill Barlow]

I have been able to split this very close double star group with a C6 and C8 when using magnifications of 200-300X.  Collimation has to be about spot on to see a black gap between the two stars.  I can almost split it with my very nice C5 and with the AP 92 Stowaway at similar magnifications.  
 

Bill

[Kim2010]

Aha! It was all seeing-related because tonight, during moments of clarity so to speak, I can clearly see a peanut-shaped object with MAYBE a thinnnnnnnnnnnnnnnn sliver of black or not, but at least the double star nature of the system is obvious due to the clean peanut shape. I used 5mm and a 2x Barlow (390x) with the 5" apo.

 

Alnitak's close double was also great to see with black space in between at 5mm no Barlow (195x).

[C. Evangelista]

Alnitak's close double was also great to see with black space in between at 5mm no Barlow (195x).

I can easily get a black-line split of Alnitak at 78x as well of 52 Ori at 130x, with my 130 f/6 triplet apo, albeit at Pickering +7.
So, mainly seeing might be an issue in your case...

[Kim2010]

I can easily get a black-line split of Alnitak at 78x as well of 52 Ori at 130x, with my 130 f/6 triplet apo, albeit at Pickering +7.
So, mainly seeing might be an issue in your case...

I'll try again tonight!