Hi there I got one of these scopes and I wasnt really satisfied with the optics,
more about that later. The scope is quite fancy looking but it does do what it says
on the tin, though Im a little unsure about the Semi-APO descriptions these
companies are using as having spoken to people who know about optics these are a
design which is about 200 or more years old and are actually called Achromats.
The scope is a little on the heavy side compared to spotters but its very portable
for an astronomy & spotting crossover telescope.
The real advantage is that you can use loads of eyepieces and other gadgets with the
scope and you can use it for digi-camming or video - the focuser is sturdy enough to
hold a large SLR with battery pack too which is a real departure from most spotters
and thats its strength. Also you can (theoretically) use it at up to about 150 x
power according to manufacturers though really it works up to about 60-80 x before
it packs up - Im not satisfied with the optics which as you can see.
I spoke to some people about the optics and they explained that this is actually
quite normal. Binoculars and small telescopes usually have achromat lenses - cheaper
to make. Anyway I looked at the APO versions of these scopes because I realised the
mechanics were basically sound, and I ended up buying an Apograde lens cell which is a way to get better performance from just about any of these 80mm William Optics clone scopes. I decided to do this after a lengthy discussion with the folks at a UK company called Altair Nature Optics who do a lot of William Optics products they have a info page on their web site below, which explains the concept with before & after pics:
http://www.bazaarbuilder.com/cgi-bin/nickaltair/myshop.php?merchant=nickaltair&prodid=496&sinprod=1
Basically its a spare lens cell for about 300 quid which screws into the front of these 80mm scopes and upgrades the lens to a better colour corrected one. It also included an extension tube and a really great little dual speed micro focuser knob which attached to the existing focuser and made it so much easier to get a fine focus. Well the whole upgrade package made an absolutely amazing difference - I could really see a lot more, especially at about 100-140x power which previously the scope just wasnt capable of, and started using it for having a look at the moon & planets. Before there was always this purple haze around bright objects in the image just like in the photos, and it was always a little soft. Contrast and sharpness was so obviously improved too it was like night and day. I know this is a birding forum but its really amazing what you can see with these things if you point them upwards, or at really distant targets - especially Saturns rings and such.
Anyway, I had some cheap eyepieces with the scope, so I decided to sort out that end of the scope too. Ended up getting a whole lot of extra stuff to use the scope on land and sky. I got a 45 degree prism diagonal (also William Optics) to give an erect image and also William Optics 20mm & 4mm wide eyepieces which have given amazing views (I wear glasses so the eye relief is great and the field of view is stunning). Took this up to Beachy Head one evening, and it was great from the landscape to ships to the moon and back.
Anyway, the controversial point is that it equals my Zeiss Diascope in every way when used with the William super wide eyepieces (which are unreal) and is sharper at high powers. In my opinion its far better value than the Zeiss which cost a LOT more than the whole package and upgrade and 2 eyepieces - but then this lens was designed for astronomy at high power, so I guess thats to be expected. To be fair, the Diascope is better to use for spotting only, and its tougher and more ergonomically friendly - plus it comes with a zoom which cant work with the same performance at high and low powers. The Zeiss is great for what it is, but as soon as you want flexibility the 80mm APO beats it in every way except for toughness, portability and durability. Im not fussed though as the views are worth it.
I have spent about 600 on accessories now! Those folks at William Optics keep making more gadgets (clever them) to add on their the scopes, which work with most of the 80mm clones out there, so now that same scope is a real performer. I kind of feel like one of those people who has supercharged their old mini or something...
With the benefit of hindsight, Id probably buy a William Optics 80mm APO in the first place as I wouldnt have to upgrade and so-on.
Anyway, bottom line is that these 80mm Achromat scopes dont really cut the mustard. The mechanics are fine but the optics just dont do it, sharpness, contrast, and colour are way below par and new technology wins. There are a lot if these semi-APO scopes around and Im not sure this marketing term is fair either, as you get the same lens design which has been around for 200 years (or so).
However, if you do already have an 80mm Achromat like the Revelation already, and get a bit more budget, then check out the upgrade options to APO. Its really worth it. If you have enough for a
William Optics original 80mm APO in the first place, then dont hesitate.
PS: If you decide to upgrade, talk to your dealer about compatibility, or have a look at that webpage link above BEFORE you buy or take your scope in to have it checked out (which they offered to do). I actually went on to buy some other William Optics stuff over the last few months as I sometimes end up in Norwich for work. I recently bought a small 50mm Toucan Spotter for birding, which I keep in the car for scenic drives after work too - I will do a review soon!
more about that later. The scope is quite fancy looking but it does do what it says
on the tin, though Im a little unsure about the Semi-APO descriptions these
companies are using as having spoken to people who know about optics these are a
design which is about 200 or more years old and are actually called Achromats.
The scope is a little on the heavy side compared to spotters but its very portable
for an astronomy & spotting crossover telescope.
The real advantage is that you can use loads of eyepieces and other gadgets with the
scope and you can use it for digi-camming or video - the focuser is sturdy enough to
hold a large SLR with battery pack too which is a real departure from most spotters
and thats its strength. Also you can (theoretically) use it at up to about 150 x
power according to manufacturers though really it works up to about 60-80 x before
it packs up - Im not satisfied with the optics which as you can see.
I spoke to some people about the optics and they explained that this is actually
quite normal. Binoculars and small telescopes usually have achromat lenses - cheaper
to make. Anyway I looked at the APO versions of these scopes because I realised the
mechanics were basically sound, and I ended up buying an Apograde lens cell which is a way to get better performance from just about any of these 80mm William Optics clone scopes. I decided to do this after a lengthy discussion with the folks at a UK company called Altair Nature Optics who do a lot of William Optics products they have a info page on their web site below, which explains the concept with before & after pics:
http://www.bazaarbuilder.com/cgi-bin/nickaltair/myshop.php?merchant=nickaltair&prodid=496&sinprod=1
Basically its a spare lens cell for about 300 quid which screws into the front of these 80mm scopes and upgrades the lens to a better colour corrected one. It also included an extension tube and a really great little dual speed micro focuser knob which attached to the existing focuser and made it so much easier to get a fine focus. Well the whole upgrade package made an absolutely amazing difference - I could really see a lot more, especially at about 100-140x power which previously the scope just wasnt capable of, and started using it for having a look at the moon & planets. Before there was always this purple haze around bright objects in the image just like in the photos, and it was always a little soft. Contrast and sharpness was so obviously improved too it was like night and day. I know this is a birding forum but its really amazing what you can see with these things if you point them upwards, or at really distant targets - especially Saturns rings and such.
Anyway, I had some cheap eyepieces with the scope, so I decided to sort out that end of the scope too. Ended up getting a whole lot of extra stuff to use the scope on land and sky. I got a 45 degree prism diagonal (also William Optics) to give an erect image and also William Optics 20mm & 4mm wide eyepieces which have given amazing views (I wear glasses so the eye relief is great and the field of view is stunning). Took this up to Beachy Head one evening, and it was great from the landscape to ships to the moon and back.
Anyway, the controversial point is that it equals my Zeiss Diascope in every way when used with the William super wide eyepieces (which are unreal) and is sharper at high powers. In my opinion its far better value than the Zeiss which cost a LOT more than the whole package and upgrade and 2 eyepieces - but then this lens was designed for astronomy at high power, so I guess thats to be expected. To be fair, the Diascope is better to use for spotting only, and its tougher and more ergonomically friendly - plus it comes with a zoom which cant work with the same performance at high and low powers. The Zeiss is great for what it is, but as soon as you want flexibility the 80mm APO beats it in every way except for toughness, portability and durability. Im not fussed though as the views are worth it.
I have spent about 600 on accessories now! Those folks at William Optics keep making more gadgets (clever them) to add on their the scopes, which work with most of the 80mm clones out there, so now that same scope is a real performer. I kind of feel like one of those people who has supercharged their old mini or something...
With the benefit of hindsight, Id probably buy a William Optics 80mm APO in the first place as I wouldnt have to upgrade and so-on.
Anyway, bottom line is that these 80mm Achromat scopes dont really cut the mustard. The mechanics are fine but the optics just dont do it, sharpness, contrast, and colour are way below par and new technology wins. There are a lot if these semi-APO scopes around and Im not sure this marketing term is fair either, as you get the same lens design which has been around for 200 years (or so).
However, if you do already have an 80mm Achromat like the Revelation already, and get a bit more budget, then check out the upgrade options to APO. Its really worth it. If you have enough for a
William Optics original 80mm APO in the first place, then dont hesitate.
PS: If you decide to upgrade, talk to your dealer about compatibility, or have a look at that webpage link above BEFORE you buy or take your scope in to have it checked out (which they offered to do). I actually went on to buy some other William Optics stuff over the last few months as I sometimes end up in Norwich for work. I recently bought a small 50mm Toucan Spotter for birding, which I keep in the car for scenic drives after work too - I will do a review soon!