Explore Scientific ED127 Triplet

[pez_espada]

Hi guys,

I guess this topic has been discussed thousand times and that there's a lot of info out there on a number of forums (including this one) on comparing the virtues of the different 5" ED/APO scopes available  on the budget. I am on the search of such a refractor and came down to the doublet FPL3 Synta ED120 F7.5 -such as those made by Skywatcher-, and the other competitor is the triplet FPL1 Explore Scientific ED127. In a number of comparison out there it is reportes that the ED120 has a slight    edge over the ED127 on color correction but others report they cannot see the differences visually. I was inclined towards the ED120 because of the uniquutous favorable reports however I just have found a very nice priced ES ED127  making it very tempting over the SW frac. I wonder now if I should pull the trigger on the 127 or the advantages of the SW ED120 (allegedly slight better color rendition, shorter temperature equilibration time, lighter OTA)  worths the higher price over the Explore Scientific 127 triplet. Your thoughts, experience and opinión are all very welcome. 

[xtreemchaos]

 if you would consider a alt 2hand scope this might fit your needs. https://stargazerslounge.com/topic/292357-altair-wave-130-f7-edt-triplet-apo-refractor/

i noticed this in the for sale sec on here, its a huge saving on new, if i had the cash id be having it. charl.

 

[alacant]

Hi. Both Skywatcher telescopes I've owned have had problems, an ed80 which I returned and a 130pds which I worked upon as there is no alternative. The ES range have the advantage of having proper focusers and being built to last.  HTH. 

*PM sent

[pez_espada]

10 hours ago, xtreemchaos said:

 if you would consider a alt 2hand scope this might fit your needs. https://stargazerslounge.com/topic/292357-altair-wave-130-f7-edt-triplet-apo-refractor/

i noticed this in the for sale sec on here, its a huge saving on new, if i had the cash id be having it. charl.

 

Thanks for the head-up, I have also considered those 130 F7, the TS versions are priced around €1900 (£1800) brand new and these new models come with the more desirable FPL3 glass instead the FPL1 of the Altair. Therefore the second-hand announced in the link is not too appealing for me at £1500. 

[ronin]

Personally I cannot see the Skywatcher ED's being better then the ES ED triplets. Also which triplet, they have 2 variants with different glasses in them. The FCD 100 glass option I have never heard/read anything but glowing comments about how good. Even the FCD-1's I would expect to out perform an ED doublet, especially at f/7.5 so they are not pushing the glass to its limits.

If the intention is imaging then I have seen images from the Skywatchers that display CA and have heard of CA on images from others. It is a poor way to put it but an ED doublet can still be considered as an achro but with better glass. Ask yourself this: Where does non-ED and ED glass diverge? Is Ohara FSL-5 low dispersion or FPM-3

[John]

I've an ED120 which I love but I've not compared it directly to an ES 127 triplet. It's done very well against my TMB / LZOS 130mm triplet though, which is about as good as a 5" triplet gets

I've read lots of reports where the ED120 performs as well or a touch better than FPL-51 and similar glass triplets, including on colour correction. The ED120 is quite a bit lighter and easier to mount plus it cools more quickly as well. The focuser does benefit from an upgrade though - I have a Moonlite on mine.

I've owned several of the ED80's, and ED100 and now the ED120. They are much better performers than equivilent achromats IMHO in both CA control (which is absolutely minimal even in the F/7.5 ones) and other aberrations. They have excellent objectives in functional tubes.