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William Optics Redcat 51 Sony A7III Equipment Refractors Buying Advice
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Wael Omar WO avatar
Wael Omar WO avatar
Hello,
I am seeking your advice about purchasing a new scope. I have ZWO 294 mm pro and Sony A7III Astromodified , Mount is Skywatcher HEQ5 . I want to upgrade from the Redcat 51 to longer focal length , 600 mm or a few more , I am thinking in ASKAR PHQ 80 mm but its a bit slow .  Budget is around 2200 $
Thank you.
Scotty Bishop avatar
Scotty Bishop avatar
Since it looks like you want to stick with a petzval type the closest you are going to get and be in budget is the SharpStar Z4 sextuplet at $2100, but it is a 100mm f/5.5 so 550mm focal length. Other than that if you can stretch your budget a little that gives you the Askar PHQ107.

If you are fine with a triplet and a flattener/reducer that opens up a bunch of options.
Wael Omar WO avatar
Wael Omar WO avatar
Scotty Bishop:
Since it looks like you want to stick with a petzval type the closest you are going to get and be in budget is the SharpStar Z4 sextuplet at $2100, but it is a 100mm f/5.5 so 550mm focal length. Other than that if you can stretch your budget a little that gives you the Askar PHQ107.

If you are fine with a triplet and a flattener/reducer that opens up a bunch of options.

*** I read some comments on the Z4 if installed with full frame camera or larger sensors , I also was thinking in the FLT 91 william optics but the reducer 1x with scope will be over 2700 $  ***
Joe Linington avatar
Joe Linington avatar
The challenge is going to be the Sony. My SharpStar 76EDPH works well with my FF A7r but my SV-503/102ed is not FF capable. It works great with my A6000 and 294m. 550-600mm FL is fantastic with the 294 in bin 1 mode.
Anderl avatar
Anderl avatar
Esprit 100
Scotty Bishop avatar
Scotty Bishop avatar
Wael Omar WO:
Scotty Bishop:
Since it looks like you want to stick with a petzval type the closest you are going to get and be in budget is the SharpStar Z4 sextuplet at $2100, but it is a 100mm f/5.5 so 550mm focal length. Other than that if you can stretch your budget a little that gives you the Askar PHQ107.

If you are fine with a triplet and a flattener/reducer that opens up a bunch of options.

*** I read some comments on the Z4 if installed with full frame camera or larger sensors , I also was thinking in the FLT 91 william optics but the reducer 1x with scope will be over 2700 $  ***

The Z4 would be more for use with your 294, or if there is a crop mode on your Sony (My Pentax full frame cameras have that) then you would need to use it.

Full frame is hard to get without spending the money for it. Even things like the Tax FSQ106 and FSQ85 struggle with full frame. I have to crop every stack from a Tak FSQ106 using the .73 reducer because the coma at the edges gets bad when using a QHY600M.
Wael Omar WO avatar
Wael Omar WO avatar
Scotty Bishop:
Wael Omar WO:
Scotty Bishop:
Since it looks like you want to stick with a petzval type the closest you are going to get and be in budget is the SharpStar Z4 sextuplet at $2100, but it is a 100mm f/5.5 so 550mm focal length. Other than that if you can stretch your budget a little that gives you the Askar PHQ107.

If you are fine with a triplet and a flattener/reducer that opens up a bunch of options.

*** I read some comments on the Z4 if installed with full frame camera or larger sensors , I also was thinking in the FLT 91 william optics but the reducer 1x with scope will be over 2700 $  ***

The Z4 would be more for use with your 294, or if there is a crop mode on your Sony (My Pentax full frame cameras have that) then you would need to use it.

Full frame is hard to get without spending the money for it. Even things like the Tax FSQ106 and FSQ85 struggle with full frame. I have to crop every stack from a Tak FSQ106 using the .73 reducer because the coma at the edges gets bad when using a QHY600M.

*** Thank you , I didnt know that even the Tak will suffer with full frame 😀 , i may reconsider my thoughts on the Z4 based on your valuable advice. ***
IrishAstro4484 avatar
IrishAstro4484 avatar
Esprit 100

*** I have the Esprit 100 and it's a wonderful scope!***