Mars, why didnt I try this before!

[Rustang]

So I started my planetary imaging journey this year with a 100mm refractor, it went ok. This week I started to wonder if I could use my old Orion 8inch reflector instead. I thought it would be to big and heavy for my HEQ5 Pro but today I dug it out and realised it felt lighter than I thought. So long story short I gave it ago! It focused without issue with the standard 1.25 R&P focuser which was fine to use so off I went with no idea if it was in collimation or not!

Orion 8 inch reflector, SW HEQ5 Pro

ZWO 224mc with Celestron 2x barlow

Firecapture, Autostakkert and Registax

3 min SER, 20% stacked of 18251 frames

Really pleased with the result.

 

 

Edited November 23, 2022 by Rustang

[Nik271]

Looks that the collimation is fine!

In planetary imging aperture rules above all, so between an 8 inch relectror and 4 inch refractor there is no contest. You don't even need a heavy duty mount because each exposure is so short. Some form of basic tracking to keep the target on the sensor is enough.

Edited November 24, 2022 by Nik271

[Rustang]

19 minutes ago, Nik271 said:

Looks that the collimation is fine!

In planetary imging aperture rules above all, so between an 8 inch relectror and 4 inch refractor there is no contest. You don't even need a heavy duty mount because each exposure is so short. Some form of basic tracking to keep the target on the sensor is enough.

Yeah the mount handled the scope fine, and considering the scope has sat around for over a year un-used it performed well to. I'm really excited to capture jupiter now 🙂

[Kon]

Great you made it working. Now you need some decent seeing to get more details out.

[Rustang]

1 hour ago, Kon said:

Great you made it working. Now you need some decent seeing to get more details out.

Sadly my sample rate is way out due to my camera/scope set up, with the x2 barlow I'm only at f10 so not great so I might not be able to get anymore details showing but worth ago.

Edited November 24, 2022 by Rustang

[Space Cowboy]

Welcome to mainstream planetary imaging 🙂 You can use an extension tube to give more fl the body of another Barlow works well or simply pull the cam nose further out from your Barlow or a combination of both.

[Rustang]

3 minutes ago, Space Cowboy said:

Welcome to mainstream planetary imaging 🙂 You can use an extension tube to give more fl the body of another Barlow works well or simply pull the cam nose further out from your Barlow or a combination of both.

I looked at getting a 3x barlow to bring it up to f15 but when I put my set up details into astronomy tools sample calculator it was even more damaging to the sample rate so I cant really up the focal length

[CraigT82]

2 minutes ago, Rustang said:

I looked at getting a 3x barlow to bring it up to f15 but when I put my set up details into astronomy tools sample calculator it was even more damaging to the sample rate so I cant really up the focal length

Ignore that calculator it’s not meant for planetary imaging.

With the 224 you want to be up around f18 ish really. 

[Rustang]

4 minutes ago, CraigT82 said:

Ignore that calculator it’s not meant for planetary imaging.

With the 224 you want to be up around f18 ish really. 

I see, I'm still learning! 😊

Ok so if I was to pull the camera out a little from the barlow, is there a guide as to how much and would I be able to bring it out far enough to achieve f18? Or would it be better to get a 3x barlow and bring it out alittle from there?

Edited November 24, 2022 by Rustang

[CraigT82]

Yeah you might need a lot of extension to get up to f18, depends on the focal length of the barlow. 
 

You can calculate the required extension using this formula:

Power=(BarlowFL+distance)/BarlowFL

If the barlow focal length isn’t published you can get it by measuring the distance between the last cell and the top of the barlow, that will be the ‘distance’, you know the power is 2x so you can rearrange and get the barlow focal length. 

[maw lod qan]

All math and calculations aside, that's a very nice image of Mars!

Pat yourself on the back!

When I manage a decent image, I remember that I'm imaging another world. I know my image is definitely poor compared to those of others, but it's mine!

[Rustang]

12 minutes ago, CraigT82 said:

Yeah you might need a lot of extension to get up to f18, depends on the focal length of the barlow. 
 

You can calculate the required extension using this formula:

Power=(BarlowFL+distance)/BarlowFL

If the barlow focal length isn’t published you can get it by measuring the distance between the last cell and the top of the barlow, that will be the ‘distance’, you know the power is 2x so you can rearrange and get the barlow focal length. 

Ok thanks, I will try and get my head around that  

[Rustang]

1 minute ago, maw lod qan said:

All math and calculations aside, that's a very nice image of Mars!

Pat yourself on the back!

When I manage a decent image, I remember that I'm imaging another world. I know my image is definitely poor compared to those of others, but it's mine!

True, I was really excited when I got the big scope up and running, I'm even more excited for Jupiter  

[Space Cowboy]

As Craig says a 3x Barlow would be better, then you can go beyond f15 with an extension tube which is what my setup is for my f5 Dob and 224mc cam. At f10 you are only in the foothills of Everest but over f15 you're reaching the summit and in very good weather you can go for glory at f20.