Dovetails just informational Generic equipment discussions · Clayton Ostler · ... · 4 · 181 · 0

I want to share something that literally was unclear to me for over a decade. Yesterday I had to sort out the terms to help a friend buy the right parts to mount a guide scope and realize this info might help other newcomers too.

There are generally 3 universal sizes of what the industry calls (dovetails).

The term dovetail was and is confusing in this hobby (at least for me) and then it gets mixed in with "Universal" and Base/Saddle/Shoe when talking about the female/base they connect to.  which even causes more confusion. 

Synta Style. (Often used for finder scopes and accessories, also used for many smaller guide scopes). This is the size of the small mounting shoe/base that is often included on top of telescopes to put in a finder scope, or attach a small guide scope, this size is also what is included as the default "dovetail" that comes wiht an asiair,  and is found on many laser pointers. The mounting base for Synta style is usually pretty small and most often is square shaped. You can pickup additional bases for synta size dovetails bases for less than 20$. I have never heard the base of a Synta dovetail described as a "saddle" but I don't pretend to know everything on this topic.  I see a lot of "Where do I get the small shoe/base/mount for my finder scope or guide scope" or "I need a dovetail that connects to the accessory base on my scope or handle", usually this is someone looking for Synta style adapters and dovetails. 

Vixen style. This is what many small to medium telescopes are mounted on by default. It is wider that the Synta and therefore better for larger weight. These is the most universal as far as a telescope mount saddle compatibility. I think generally this is what most people think of when they think of an Astronomy Dovetail. 

Losmandy style (often called D size). These are about twice as wide as the Vixen style. These are great for many things but generally are the saddle and base for telescopes. For many years I thought that this was used for higher end scopes, heavier scopes or scopes mostly focused on astrophotography. I still personally think this is true, but it is not a rule or standard by any means. These dovetails typically cost the most of the 3 mentioned here.  
In my early days of this hobby I purchased a couple of these only to find out my mount didn't support them so they were expensive paper weights. I personally have only ever used these to mount a actual telescope, it seems like overkill for finders guide scope, accessories etc. But there's not reason you could not use this for those items as long as you have a saddle to connect it to.

Keeping.  these 3 straight will save you a lot of headaches.  I know there are other "lesser known" or "less common" versions too, but I am trying to keep this as simple as possible for newbies and simple minded guys like myself. 

Last part, the hole patterns and sizes in these dovetail bars and their associated  bases/shoe/saddles is not NOT universal. This has burned me for a few hundred dollars over the last decade, make sure that you know the bolt/screw size and patterns if you intend to connect something directly to the respective dovetail. 

For years I didn't know the term (Synta style) and would Google looking for a guide scope base or accessories bar etc. And had no idea if it would work. Example, telescope mount "accessory bar or shoe" is really just saying Synta style/size shoe or base.  

For years I would go on ebay and buy a cheap Vixen Style dovetail bar, only to find out it didn't have the bolt holes needed to line up with telescope rings or some specific item I hoped to mount directly to the bar. 

I hope this is helpful to someone, somewhere. 
Clear Skies.

Clayton Ostler:
I want to share something that literally was unclear to me for over a decade. Yesterday I had to sort out the terms to help a friend buy the right parts to mount a guide scope and realize this info might help other newcomers too.

There are generally 3 universal sizes of what the industry calls (dovetails).

The term dovetail was and is confusing in this hobby (at least for me) and then it gets mixed in with "Universal" and Base/Saddle/Shoe when talking about the female/base they connect to.  which even causes more confusion. 

Synta Style. (Often used for finder scopes and accessories, also used for many smaller guide scopes). This is the size of the small mounting shoe/base that is often included on top of telescopes to put in a finder scope, or attach a small guide scope, this size is also what is included as the default "dovetail" that comes wiht an asiair,  and is found on many laser pointers. The mounting base for Synta style is usually pretty small and most often is square shaped. You can pickup additional bases for synta size dovetails bases for less than 20$. I have never heard the base of a Synta dovetail described as a "saddle" but I don't pretend to know everything on this topic.  I see a lot of "Where do I get the small shoe/base/mount for my finder scope or guide scope" or "I need a dovetail that connects to the accessory base on my scope or handle", usually this is someone looking for Synta style adapters and dovetails. 

Vixen style. This is what many small to medium telescopes are mounted on by default. It is wider that the Synta and therefore better for larger weight. These is the most universal as far as a telescope mount saddle compatibility. I think generally this is what most people think of when they think of an Astronomy Dovetail. 

Losmandy style (often called D size). These are about twice as wide as the Vixen style. These are great for many things but generally are the saddle and base for telescopes. For many years I thought that this was used for higher end scopes, heavier scopes or scopes mostly focused on astrophotography. I still personally think this is true, but it is not a rule or standard by any means. These dovetails typically cost the most of the 3 mentioned here.  
In my early days of this hobby I purchased a couple of these only to find out my mount didn't support them so they were expensive paper weights. I personally have only ever used these to mount a actual telescope, it seems like overkill for finders guide scope, accessories etc. But there's not reason you could not use this for those items as long as you have a saddle to connect it to.

Keeping.  these 3 straight will save you a lot of headaches.  I know there are other "lesser known" or "less common" versions too, but I am trying to keep this as simple as possible for newbies and simple minded guys like myself. 

Last part, the hole patterns and sizes in these dovetail bars and their associated  bases/shoe/saddles is not NOT universal. This has burned me for a few hundred dollars over the last decade, make sure that you know the bolt/screw size and patterns if you intend to connect something directly to the respective dovetail. 

For years I didn't know the term (Synta style) and would Google looking for a guide scope base or accessories bar etc. And had no idea if it would work. Example, telescope mount "accessory bar or shoe" is really just saying Synta style/size shoe or base.  

For years I would go on ebay and buy a cheap Vixen Style dovetail bar, only to find out it didn't have the bolt holes needed to line up with telescope rings or some specific item I hoped to mount directly to the bar. 

I hope this is helpful to someone, somewhere. 
Clear Skies.

It's not hard to drill holes in aluminum...

didn't know about the Synta one, thank you

I never knew the name for it