Posts Made By: Dave Adams

I am wondering if anyone has compared the Meade 4000 series plossls, Celestron ultimas and Televue plossls. I am planning to use them for planetary viewing in a binoviewer.
The focal lengths that would work for my scopes w/binoviewer and barlow are one pair 30-32mm and another pair of 18-20mm
and possibly a third pair in the 12-15mm range.

I have a set of Meade 4000 series plossls on backorder from Meade when I ordered one of their scopes so can double up on these cheaply but have read somewhat mixed reviews on these at excelsis.com compared to the TV and ultimas. Thanks for
any advice.

Dave Adams

Hi,

I am looking for eyepieces for binoviewing and was wondering which would be sharper and give better contrast for planet viewing, ultrascopics or uo orthos (old or new HD)? I have read good reports on both and need eyepieces in the 20 to 10 range. I have heard around 10mm the ultracopics get harder to use than an equivalent ortho and maybe I should mix orthos (9 & 12) and ultrascopics (20 & 15) if they are really close in performance.
Thanks.

Dave

Hi,

I am looking for eyepieces for binoviewing and was wondering which would be sharper and give better contrast for planet viewing, ultrascopics or uo orthos (old or new HD)? I have read good reports on both and need eyepieces in the 20 to 10 range. I have heard around 10mm the ultracopics get harder to use than an equivalent ortho and maybe I should mix orthos (9 & 12) and ultrascopics (20 & 15) if they are really close in performance.
Thanks.

Dave

Hi,

I am looking for a portable travel scope and have narrowed the choice to either an Intes M503 5" f/10 and a StarMax 127. The Intes costs more $799 vs $399 but has the following advanteges from what I have been able to determine:

-fully illuminated field for 2" eyepieces allowing ~2 deg fov vs ~1.3 fov for the StarMax

-Intes comes with 2" star diagonal

-Intes fit/finish look nicer in pictures at ITE website

-Intes optics better?

The StarMax has enough focus travel for binoviewing use and I am not sure about the Intes. Has anyone tried a binoviewer in the Intes M503?

Has anyone compared views in these two scopes? Are there other reasons to go with one or the other? Thanks.

Dave Adams

I was very fortunate to purchase a used D&G 5" f/10 a few months ago and have been very happy with the views. The optics in the D&G are outstanding and really pull away from several of the Chineese refractors I have at high power. I am wondering how much difference there is between a D&G 5" and an AP 130mmf/6 on planetary/lunar viewing.

I put myself on the wait list for an AP 130 f/6 and know that I will never be sorry in getting one. I am just curious how much of an improvement it will provide over the D&G I have. I have a Baader Contrast Booster filter which acts as a minus violet filter but haven't felt the need to use it yet. I am going to try that out and think about getting a chromacorr. I have done more reading
about refractor optics and it seems spherical aberration is more important than the chromatic aberrations and that really good achromats like the D&G do a better job at limting chromatic aberrations than the Chineese refractors. That being said, the D&G is a really nice scope and I am tempted to get a 5" f/10 or f/12 just to get the upgraded AP focuser and adjustable lense cell that mine does not have.

Dave Adams

I was very fortunate to purchase a used D&G 5" f/10 a few months ago and have been very happy with the views. The optics in the D&G are outstanding and really pull away from several of the Chineese refractors I have at high power. I am wondering how much difference there is between a D&G 5" and an AP 130mmf/6 on planetary/lunar viewing.

I put myself on the wait list for an AP 130 f/6 and know that I will never be sorry in getting one. I am just curious how much of an improvement it will provide over the D&G I have. I have a Baader Contrast Booster filter which acts as a minus violet filter but haven't felt the need to use it yet. I am going to try that out and think about getting a chromacorr. I have done more reading
about refractor optics and it seems spherical aberration is more important than the chromatic aberrations and that really good achromats like the D&G do a better job at limting chromatic aberrations than the Chineese refractors. That being said, the D&G is a really nice scope and I am tempted to get a 5" f/10 or f/12 just to get the upgraded AP focuser and adjustable lense cell that mine does not have.

Hi,

I am thinking of getting a used Tak 128 and am wondering about the flourite element. I have read references to flourite being fragile and was wondering what this means in regards to use. Do you have to be careful in that it may crack due to impact, cleaning or will it degrade over time?

I live in Michigan and like that the Tak has only 2 elements and wonder if this would be an advantage over a triplet in cool down times and thermal stability? Also, I have always wondered if there are any problems with oil spaced triplets leaking oil over time? Thanks.

Dave Adams

Hi,

I am thinking of getting a used Tak 128 and am wondering about the flourite element. I have read references to flourite being fragile and was wondering what this means in regards to use. Do you have to be careful in that it may crack due to impact, cleaning or will it degrade over time?

I live in Michigan and like that the Tak has only 2 elements and wonder if this would be an advantage over a triplet in cool down times and thermal stability? Also, I have always wondered if there are any problems with oil spaced triplets leaking oil over time? Thanks.

Dave Adams

On my quest for the "scope of a lifetime", I think I have narrowed the choice to a Tak FS-128 or TEC 140. I have compiled the following information and am hoping for comments.

Tak FS-128

Advantages: lower weight 16.5 vs 18.8 lbs for TEC140, flourite doublet- faster cooling?, air-spaced- don't have to worry about oil leaking or oil degrading over time, less expensive on used market, dew shield easier to move

TEC 140

Advantages: triplet - slightly? better color correction,
10 mm greater apeture, better focuser - smoother, fine focus knob and rotatable.

I haven't heard many people buying synta's matched with a chromacorr so am thinking there performance must be a notch below a true apo like a TAK or TEC but would welcome any comments on this. I saw that APM used to sell 120 mm synta's matched with chromacorrs for ~1,500 or so.

I thought a 2 element air spaced lense would cool faster due to less mass up front but someone mentioned to me that the air space acts as a thermal insulator so that the inside lense takes a long time to cool. Has anyone compared the cooldown times of an oil spaced triplet to an air spaced doublet?

Also, on another list, someone mentioned that the oil in a triplet can degrade over time affecting the performance of the scope. The degredation mentioned was not great but enough that owners of some oil spaced triplets payed to have them refurbished with new oil. Has anyone heard of this issue?

Dave Adams

On my quest for the "scope of a lifetime", I think I have narrowed the choice to a Tak FS-128 or TEC 140. I have compiled the following information and am hoping for comments.

Tak FS-128

Advantages: lower weight 16.5 vs 18.8 lbs for TEC140, flourite doublet- faster cooling?, air-spaced- don't have to worry about oil leaking or oil degrading over time, less expensive on used market, dew shield easier to move,
not sure if available in shorter binoviewer version.

TEC 140

Advantages: triplet - slightly? better color correction,
10 mm greater apeture, better focuser - smoother, fine focus knob and rotatable, can specify tube length 80mm shorter for use with binoviewer w/o compensators for no extra cost.

I haven't heard many people buying synta's matched with a chromacorr so am thinking there performance must be a notch below a true apo like a TAK or TEC but would welcome any comments on this. I saw that APM used to sell 120 mm synta's matched with chromacorrs for ~1,500 or so.

I thought a 2 element air spaced lense would cool faster due to less mass up front but someone mentioned to me that the air space acts as a thermal insulator so that the inside lense takes a long time to cool. Has anyone compared the cooldown times of an oil spaced triplet to an air spaced doublet?

Also, on another list, someone mentioned that the oil in a triplet can degrade over time affecting the performance of the scope. The degredation mentioned was not great but enough that owners of some oil spaced triplets payed to have them refurbished with new oil. Has anyone heard of this issue?

Dave Adams