NEW Sky-Watcher 0.77x Reducers for Esprit 120 & 150

[msacco]

13 minutes ago, Ken82 said:

Personally I’d get the dedicated reducer if I was using a camera under 34mm diagonal. 
 

ken 

Oh yeah, I'm using the ASI071MC Pro, wanted to mention that as well

[gilesco]

19 minutes ago, Ken82 said:

Personally I’d get the dedicated reducer if I was using a camera under 34mm diagonal. 
 

ken 

Yes -  also don't have my Esprit 120 yet, but having worked with AP on my f/5 ST with all the issues that that entails, would be nice to work at f/5.4 = rather than f/7. Hope to get some opportunities at f/7 first then look at the reducer.

Edited November 14, 2020 by gilesco

[Astrobug]

You will never have a full frame reducer for an esprit. It is 34 = 44x0.77. For the price it is a good deal. If the stars are fine in the corners i don´t see an issue. Good job SW.

Edited November 14, 2020 by Astrobug

[Sp@ce_d]

Mine arrived today.. (Thank you @FLO prompt service as always )...  along with more rain.. let alone clouds! That's over a month now with no let up.. no idea when I'll get a chance to test it.. if this year!

Meantime.. here's some pics & initial thoughts. If you are someone that judges value by weight then you certainly won't be disappointed. It has a very solid and well built "attitude" about it. Smooth, clean feeling threads, very happy

Pics show the adapter taken apart to reveal the 2" filter thread.. I've fitted one to show it clearer. Also, less bits are needed with this to attach it to the scope. It fits straight onto the tube rather than needing the extra reducer that the standard flattener uses. One observation I think is an error on @FLO's website. The adapter presents as M48 which is correct in the description but the list of Features and Specs talks about a T2 adapter? As with the standard flattener you'll need an M48 to T2 adapter if going to a T2 thread as I am with my QSI that's going on this. Other than that, I'm at the mercy of the weather until I can get some photons through it to see how it performs.

 

[Laurin Dave]

1 hour ago, Sp@ce_d said:

Mine arrived today.. (Thank you @FLO prompt service as always )...  along with more rain.. let alone clouds! That's over a month now with no let up.. no idea when I'll get a chance to test it.. if this year!

Meantime.. here's some pics & initial thoughts. If you are someone that judges value by weight then you certainly won't be disappointed. It has a very solid and well built "attitude" about it. Smooth, clean feeling threads, very happy

Pics show the adapter taken apart to reveal the 2" filter thread.. I've fitted one to show it clearer. Also, less bits are needed with this to attach it to the scope. It fits straight onto the tube rather than needing the extra reducer that the standard flattener uses. One observation I think is an error on @FLO's website. The adapter presents as M48 which is correct in the description but the list of Features and Specs talks about a T2 adapter? As with the standard flattener you'll need an M48 to T2 adapter if going to a T2 thread as I am with my QSI that's going on this. Other than that, I'm at the mercy of the weather until I can get some photons through it to see how it performs.

 

Aha your last picture explains my mystery... it fits inside the drawtube! I couldn't figure out from the photos FLO posted how it fitted on to the scope, but I see now its an M74thread. 

Dave

[gorann]

It is great that these reducers were finally made. They have been greatly missed and perfect for APS-C and smaller sensors. "Unfortunately" I have now invested in a full frame ASI6200 for my Esprit 150 so a reducer would be useless. I could use one for my Esprit 100 but as I understand it, it still does not exist.

[msacco]

2 hours ago, Laurin Dave said:

Aha your last picture explains my mystery... it fits inside the drawtube! I couldn't figure out from the photos FLO posted how it fitted on to the scope, but I see now its an M74thread. 

Dave

Looks great! Can't wait for the image

1 hour ago, gorann said:

It is great that these reducers were finally made. They have been greatly missed and perfect for APS-C and smaller sensors. "Unfortunately" I have now invested in a full frame ASI6200 for my Esprit 150 so a reducer would be useless. I could use one for my Esprit 100 but as I understand it, it still does not exist.

If you don't already have another solution, I believe the APM reducer should work for full frame and work well with the Esprit.

Edited November 18, 2020 by msacco

[gorann]

15 minutes ago, msacco said:

Looks great! Can't wait for the image

If you don't already have another solution, I believe the APM reducer should work for full frame and work well with the Esprit.

No reducer can work for a full frame chip (=43 mm diagonal) with the Esprits since they are already full frame (40 - 44 mm imaging circle with Esprit 100 - 150) so a reducer would only cause a dark ring along the edges with a full frame camera and loss of resolution, so utterly useless. For Esprit 150, the image circle with the new reducer would be 44mm x 0.77 = 34 mm, so it would just about fill the frame of an APS-C.

[msacco]

On 19/11/2020 at 00:47, gorann said:

No reducer can work for a full frame chip (=43 mm diagonal) with the Esprits since they are already full frame (40 - 44 mm imaging circle with Esprit 100 - 150) so a reducer would only cause a dark ring along the edges with a full frame camera and loss of resolution, so utterly useless. For Esprit 150, the image circle with the new reducer would be 44mm x 0.77 = 34 mm, so it would just about fill the frame of an APS-C.

 I know someone who imaged with Esprit 120mm, riccardi APM reducer, and a full frame DSLR - the stars were pretty much perfect from edge to edge. Without crop ofc.

Again, don't know how good that would actually be as I didn't try myself, and I'm running aps-c anyhow so that doesn't really bother me, just though I'd share this experience.

[Nikolas64]

Would these work in other telescopes or are they purely for skywatchers?

[Juicy6]

Talking about reducers, the Starizona 0.65 seems to be in stock finally. Can be ordered with threaded adapter for Esprit 100. Anyone here tried it?

https://starizona.com/store/apexed-threaded-focuser-adapter

Christer, Sweden

[SimM]

When I first saw the 0.77x Reducer, I thought that's nice and had it been available previously, it would have brought the Esprit 120 a more interesting choice to consider.

However, even with the Reducer, the FOV is some 17% smaller than an Esprit 100 for a comparable f/5.x "speed" and the image circle is also reduced 0.77x times.

So, I see it as a perfect accessory for 120 owners, but not something that is going to be essential for 100 owners, as they already have a wide FOV without needing a Reducer.

That said, there aren't too many Reducer options for the 100 especially as I'm not aware of anything in the region of 0.8x as perhaps the Apex is a bit too much with 0.65x ( easy to get in Europe?)

It must be harder to make a good Reducer for a shorter FL than for one that is a bit longer, so f/7 down to f/5.4 (e.g. for the Esprit 120 or 150) seems much more "doable" but for the 100, not so easy to "pull off", so I have my doubts that it will be just around the corner for 100 owners. Perhaps that is why it is branded for make and model explicitly.

SW presentation paired the Reducer with a FF camera, but they didn't say if the images had been cropped. Curiously, the whole SW presentation was reversed (left - right) so screwing on attachments looked to be LH threads (when they are not).

[Adam J]

On 09/12/2020 at 01:47, SimM said:

When I first saw the 0.77x Reducer, I thought that's nice and had it been available previously, it would have brought the Esprit 120 a more interesting choice to consider.

However, even with the Reducer, the FOV is some 17% smaller than an Esprit 100 for a comparable f/5.x "speed" and the image circle is also reduced 0.77x times.

So, I see it as a perfect accessory for 120 owners, but not something that is going to be essential for 100 owners, as they already have a wide FOV without needing a Reducer.

That said, there aren't too many Reducer options for the 100 especially as I'm not aware of anything in the region of 0.8x as perhaps the Apex is a bit too much with 0.65x ( easy to get in Europe?)

It must be harder to make a good Reducer for a shorter FL than for one that is a bit longer, so f/7 down to f/5.4 (e.g. for the Esprit 120 or 150) seems much more "doable" but for the 100, not so easy to "pull off", so I have my doubts that it will be just around the corner for 100 owners. Perhaps that is why it is branded for make and model explicitly.

SW presentation paired the Reducer with a FF camera, but they didn't say if the images had been cropped. Curiously, the whole SW presentation was reversed (left - right) so screwing on attachments looked to be LH threads (when they are not).

I completely agree one of the things I liked about the 100 was that you could have a fast scope without the reducer. Reducers are far harder to get right. 

[SimM]

8 hours ago, Adam J said:

Reducers are far harder to get right. 

A Reducer that is 0.65x is more "difficult" to get right than a more modest 0.8x and the image circle is reduced e.g. 0.65x X 43mm vs 0.8 X 43mm vs 43mm (not reduced), so a Reducer is not a "magic" panacea. Cropping the image is both wasteful of the camera sensor and cropping an already smaller FOV is limiting and wasteful, considering the starting size of aperture. So I see it as an additional and very useful addition for 120/150 owners. 100's are a good match for your EQ6 sized mount for AP, so there is something for everyone.

[Bruceo]

Sky-watcher said they are now available to pre-order from their dealers,  what dealers are going to have them.

bruce

[Frank_Teunissen]

I own an “older” Esprit 150ED with the red marks on it. The new dedicated SW reducer 0.77x for the Esprit 150ED won’t fit into drawtube of the focusser. Why doesn’t SkyWatcher warn the users of these Esprit’s?

 

 

Edited January 8, 2021 by Frank_Teunissen

[msacco]

On 07/01/2021 at 23:21, Frank_Teunissen said:

I own an “older” Esprit 150ED with the red marks on it. The new dedicated SW reducer 0.77x for the Esprit 150ED won’t fit into drawtube of the focusser. Why doesn’t SkyWatcher warn the users of these Esprit’s?

 

 

Is it possible to replace that to match?

[Sp@ce_d]

Oh.. doesn’t that M74 unscrew off the end of the tube to reveal an M86 male thread?

[Frank_Teunissen]

No, it doesn't: 

 

[rodrigol]

On 14/11/2020 at 20:52, msacco said:

Oh yeah, I'm using the ASI071MC Pro, wanted to mention that as well

Fantastic! Could you please post an image of how you connected the reducer to the camera? 

[msacco]

On 10/02/2021 at 17:12, rodrigol said:

Fantastic! Could you please post an image of how you connected the reducer to the camera? 

I don't own the Esprit 120 yet, so sorry can't help with that 😕

[dagerber]

On 18/11/2020 at 19:56, Sp@ce_d said:

Pics show the adapter taken apart to reveal the 2" filter thread.. I've fitted one to show it clearer. Also, less bits are needed with this to attach it to the scope. It fits straight onto the tube rather than needing the extra reducer that the standard flattener uses. One observation I think is an error on @FLO's website. The adapter presents as M48 which is correct in the description but the list of Features and Specs talks about a T2 adapter? As with the standard flattener you'll need an M48 to T2 adapter if going to a T2 thread as I am with my QSI that's going on this. Other than that, I'm at the mercy of the weather until I can get some photons through it to see how it performs.

Hi @Sp@ce_d

I have the reducer for the Esprit 120. I've not used it yet, so I looked up how to hook up the camera with correct backfocus.
https://www.skywatcherusa.com/products/0-77x-reducer-flattener-for-esprit-120 says "95mm back-focus (55mm when back focus spacer and M48 ring installed)"

 

I think 95mm is wrong and it should be

"80mm back-focus (55mm when back focus spacer and M48 ring installed)"

 

Drawing top: Reducer + Focus-spacer + M72/M48 Adapter => 55mm backfocus

Drawing bottom: Reducer + M72/M48 Adapter (without the Focus-spacer) => 75mm backfocus

 

 

 

Here my setup with an ASI2600MC that I hope I got right:
My Off-axis guider "collided" with the focus-spacer and adapter ring of the reducer because they have quite a substantial diameter. I guess a M68 Off-axis guider would work, but mine is the small one.
Therefore I removed the focus spacer that came with the reducer and added a 20mm spacer instead after the M48 Adapter ring.
 

 

 

 

What do you think?

 

Daniel

 

Edited February 17, 2021 by dagerber

[Sp@ce_d]

3 hours ago, dagerber said:

Hi @Sp@ce_d

I have the reducer for the Esprit 120. I've not used it yet, so I looked up how to hook up the camera with correct backfocus.
https://www.skywatcherusa.com/products/0-77x-reducer-flattener-for-esprit-120 says "95mm back-focus (55mm when back focus spacer and M48 ring installed)"

 

I think 95mm is wrong and it should be

"80mm back-focus (55mm when back focus spacer and M48 ring installed)"

 

Drawing top: Reducer + Focus-spacer + M72/M48 Adapter => 55mm backfocus

Drawing bottom: Reducer + M72/M48 Adapter (without the Focus-spacer) => 75mm backfocus

 

 

 

 

Here my setup with an ASI2600MC that I hope I got right:
My Off-axis guider "collided" with the focus-spacer and adapter ring of the reducer because they have quite a substantial diameter. I guess a M68 Off-axis guider would work, but mine is the small one.
Therefore I removed the focus spacer that came with the reducer and added a 20mm spacer instead after the M48 Adapter ring.
 

 

 

 

 

What do you think?

 

Daniel

 

Hi dagerber and welcome to the forum  

It's the usual 55mm as it comes in the box, unless using a custom adapter, which for my 150 they are quoting 75mm.

So for yours, you are looking at 37.5mm once you take into account the 17.5mm of the camera already.

 

[dagerber]

OK, thank you.
I also contacted Skywatcher, they replied the 95mm is measured from the edge as shown below.
 

 

Edited February 17, 2021 by dagerber

[dagerber]

OK, got my first image with the reducer and the stars look actually pretty good! Taken with Skywatcher Esprit 120 ED, the 0,77 Reducer and Optolong L-extreme. 4.8h integration time.
See https://www.astrobin.com/oej14k/