Plans for a beginner equipment

[Miroslav]

Hi to all!

I am new in the forum and have no experience with the telescopes. For my luck I found FLO and the guys there help me a lot. Also I play with this calculator so I can try to understand what can be my first equipment. Also I want to apologize, because English is not my native language, and because of this I may ask more than usual

My idea is to use HEQ5 GoTo SynScan as base, in case later decide to get 6" or 8" SCT.

My first idea for telescope was ZenithStar 73, but reading here and there, and playing with the FOV calculator I changed my plans. As total beginner may be the wiser will be to get an Explorer 130PDS. There are lot of good opinions about this telescope, and there are lot of nice astro photos too. The price is also much lower.

I hope to use the telescope for visual observations and astro-photography. Testing the 150PDS in the calculator with the Messiers looks like a magnification of x130 (exit pupil about 1mm) is enough for most of the smallest objects in the list. Testing the telescope with Jupiter, Saturn, Venus and Mars, and exit pupil about 0.5 (magnification about 200x) I may get acceptable views of them.

I accept corrections and comments about all above because it is only "on paper"

The 150PDS come with 2" focuser and adapter for 1.25" if I am not wrong, also "Eyepiece Supplied 28mm (2"/50.8mm)" - I am not sure how to understand this. Looks like I will need one or two more eyepieces and a Barlow/Powermate. And I am not sure how to combine them.

For example the Whirlpool galaxy is good at 130x. This mean 2x barlow and 10mm eyepiece or just 5mm eyepiece. For Lagoon nebula 28mm with 2x barlow is OK. For Jupiter 2x barlow with 5mm eyepiece (260x and exit pupil about 0.5) is may be the maximum I can get.

Talking about the barlows, is the performance of the powermate worth the bigger price?

I read on some place the small eyepieces (high magnification) are usually 1.25", the big eyepieces (as 28")  are 2". I looked at Baader eyepieces betweeh 4.5 and 12mm, all of them can be used with 2" and 1.25". So what Barlow/Powermate is wiser to buy - 1.25" or 2"? If I got 1.25" x2 is there adapter for 2" eyepieces?

I read very good opinions about Baader Hyperion and Morpheus, but if someone recommend me alternatives will be nice to know.

Another thing I do not understand is where I have to attach the Comma Correcter and some light pollution/nebulae filter - at the focuser or on some of the other parts of the system?

Also it will be great if someone recommend me first filter. I will use not modified Fujifilm X-T3 camera. In astrobackyard recommended filter is CLS type. Looking for those filters in FLO I spotted in their names CCD, is that mean they are for CCD matrix? Mine must be BSI, if I am not wrong, with X-Trans layer, not Bayer, who is typical for Fuji crop cameras.

Another question is - is the focuser strong enough to attach on it barlow/powermate, eyepiece and at the end my mirrorless camera? Talking with the guys from FLO it looks like I can attach the camera wherever I want with proper T-Rings.

Thanks and best regards!

[vlaiv]

Hi and welcome to SGL.

HEQ5 + 130PDS is very nice starter setup.

Most frequently used eyepieces are 1.25" and 2" - larger ones are used when you want larger field of view.

Don't get carried away with magnification. For general observing you'll be using magnification in x30-x50 range with some targets requiring a bit more magnification (up to say x100 on small planetary nebulae). It would be good to get yourself familiar with what you'll be able to see to set your expectations right. Here is nice video explaining things:

https://www.youtube.com/watch?v=jI7IPPmu76U

In fact - you'll find several videos on this subject if you do the search:

https://www.youtube.com/results?search_query=telescope+expectation+vs+reality

For this reason - FOV calculator that show you image of object can be a bit misleading in what you'll see - as these use photos rather than trying to simulate actual targets.

1 hour ago, Miroslav said:

For example the Whirlpool galaxy is good at 130x.

Not sure if I ever observed M51 at such high power with small or even larger scope.

This looks nice, doesn't it:

But that red circle is larger than your computer screen so M51 would take up half of your screen. that is just too large / magnified.

In reality - it will be more like this:

Actual / realistic size of object that you'll see (say you are sitting 60cm away from computer screen).

That is about it - you'll see two cores and that will be at much lower magnification - like x50 or similar. Maybe, if you are lucky and have excellent night and you are in very dark location and M51 is high up in the sky, you'll be able to see it like this:

(hint of bridge and some spiral structure visible)

On different end of spectrum are planets - you'll need magnifications up to x200 realistically. In most cases you won't be able to use x200 due to atmosphere.

Not sure if you'll benefit from barlow lens at the beginning, since you are mentioning Morpheus eyepieces. Usually barlows work to get extend magnification range of few eyepieces and save money on those. Instead of jumping straight at Morpheus (skip Hyperions - they will be very poor at F/5) - look into getting nice set of BST StarGuiders.  You can get like 4-5 of those for price of single Morpheus eyepiece.

Nothing wrong with Morpheus eyepieces and if you have the budget - go for them, but I think that you'll appreciate them more once you learn how to observe. Observing is a skill and you learn it by practice. Once you have some experience - then you'll now what sort of eyepieces you like. BST StarGuiders are very nice upgrade from stock eyepieces, and since you'll be using 130PDS - they will form very nice set to get you going.

1 hour ago, Miroslav said:

Another thing I do not understand is where I have to attach the Comma Correcter and some light pollution/nebulae filter - at the focuser or on some of the other parts of the system?

You'll attach any filter to coma corrector, then coma corrector to extension tube, then extension tube to T2-Lens adapter for your camera and camera in the end. It will all look like this:

and is inserted into focuser like this:

1 hour ago, Miroslav said:

Also it will be great if someone recommend me first filter. I will use not modified Fujifilm X-T3 camera. In astrobackyard recommended filter is CLS type. Looking for those filters in FLO I spotted in their names CCD, is that mean they are for CCD matrix? Mine must be BSI, if I am not wrong, with X-Trans layer, not Bayer, who is typical for Fuji crop cameras.

Don't worry about type of matrix on your sensor - there is software support that will deal with getting images from raw format and making astro photography out of it. There are plenty of tutorials both on youtube and here on SGL to show how it is done.

Best filter will depend on type of light pollution that you have and target that you are imaging.

For emission type nebulae - UHC filter works very good, while for general AP look into LP suppression filters - I used to use IDAS LPS P2 because there was plenty of sodium lights in my home town. If most of LP is in form of LEDs - look into different model like IDAS LPS D4 (or whatever the actual model name is) - or ask here on SGL depending on your budget.

1 hour ago, Miroslav said:

Another question is - is the focuser strong enough to attach on it barlow/powermate, eyepiece and at the end my mirrorless camera? Talking with the guys from FLO it looks like I can attach the camera wherever I want with proper T-Rings.

130PDS is different than 130P because it has DS - dual speed focuser that is made for imaging. It is good enough to hold camera and coma corrector (which is actually inserted in focuser).

Mirrorless camera is lighter than regular DSLR - so you'll be fine, and yes - you'll need T-ring for your camera model, and you'll also need to calculate proper distance. Cameras have flange focal distance - which means how far away lens must focus to properly focus on sensor itself. See here:

https://en.wikipedia.org/wiki/Flange_focal_distance

T-ring for your camera has certain optical length that is specified and coma corrector has certain working distance - you must match things to get good image:

coma corrector working distance = flange focal distance + T2 optical path length + any needed spacers.

 

[Miroslav]

16 hours ago, vlaiv said:

Hi and welcome to SGL.

HEQ5 + 130PDS is very nice starter setup.

Most frequently used eyepieces are 1.25" and 2" - larger ones are used when you want larger field of view.

Don't get carried away with magnification. For general observing you'll be using magnification in x30-x50 range with some targets requiring a bit more magnification (up to say x100 on small planetary nebulae). It would be good to get yourself familiar with what you'll be able to see to set your expectations right. Here is nice video explaining things:

https://www.youtube.com/watch?v=jI7IPPmu76U

In fact - you'll find several videos on this subject if you do the search:

https://www.youtube.com/results?search_query=telescope+expectation+vs+reality

For this reason - FOV calculator that show you image of object can be a bit misleading in what you'll see - as these use photos rather than trying to simulate actual targets.

Not sure if I ever observed M51 at such high power with small or even larger scope.

This looks nice, doesn't it:

But that red circle is larger than your computer screen so M51 would take up half of your screen. that is just too large / magnified.

In reality - it will be more like this:

Actual / realistic size of object that you'll see (say you are sitting 60cm away from computer screen).

That is about it - you'll see two cores and that will be at much lower magnification - like x50 or similar. Maybe, if you are lucky and have excellent night and you are in very dark location and M51 is high up in the sky, you'll be able to see it like this:

(hint of bridge and some spiral structure visible)

On different end of spectrum are planets - you'll need magnifications up to x200 realistically. In most cases you won't be able to use x200 due to atmosphere.

Not sure if you'll benefit from barlow lens at the beginning, since you are mentioning Morpheus eyepieces. Usually barlows work to get extend magnification range of few eyepieces and save money on those. Instead of jumping straight at Morpheus (skip Hyperions - they will be very poor at F/5) - look into getting nice set of BST StarGuiders.  You can get like 4-5 of those for price of single Morpheus eyepiece.

Nothing wrong with Morpheus eyepieces and if you have the budget - go for them, but I think that you'll appreciate them more once you learn how to observe. Observing is a skill and you learn it by practice. Once you have some experience - then you'll now what sort of eyepieces you like. BST StarGuiders are very nice upgrade from stock eyepieces, and since you'll be using 130PDS - they will form very nice set to get you going.

You'll attach any filter to coma corrector, then coma corrector to extension tube, then extension tube to T2-Lens adapter for your camera and camera in the end. It will all look like this:

and is inserted into focuser like this:

Don't worry about type of matrix on your sensor - there is software support that will deal with getting images from raw format and making astro photography out of it. There are plenty of tutorials both on youtube and here on SGL to show how it is done.

Best filter will depend on type of light pollution that you have and target that you are imaging.

For emission type nebulae - UHC filter works very good, while for general AP look into LP suppression filters - I used to use IDAS LPS P2 because there was plenty of sodium lights in my home town. If most of LP is in form of LEDs - look into different model like IDAS LPS D4 (or whatever the actual model name is) - or ask here on SGL depending on your budget.

130PDS is different than 130P because it has DS - dual speed focuser that is made for imaging. It is good enough to hold camera and coma corrector (which is actually inserted in focuser).

Mirrorless camera is lighter than regular DSLR - so you'll be fine, and yes - you'll need T-ring for your camera model, and you'll also need to calculate proper distance. Cameras have flange focal distance - which means how far away lens must focus to properly focus on sensor itself. See here:

https://en.wikipedia.org/wiki/Flange_focal_distance

T-ring for your camera has certain optical length that is specified and coma corrector has certain working distance - you must match things to get good image:

coma corrector working distance = flange focal distance + T2 optical path length + any needed spacers.

 

Thank you for the nice response!

Especially for the real example of seeing M51 ! The eyepiece will not as the screen... I missed this

Last night when I post my topic I was sleepy and miss something to mention. First I recently understand that when view DSOs they looks black and white because of this I will be happy to can see the biggest of Messiers like Andromeda, Lagoon nebula and Pleiades. So my real plan is get good enough photos of them. And thinking of this I again ask myself - is a small refractor telescope (ED80 or ZS73) be a better option? Yes they are more expensive, but also smaller and probably better for AP. If viewing experience over some of those refractor would be same, may be it will be better to get one of them?

And talking about you real example above the situation with the planets will not be better than with M51. In this case is realistic to try 250-260x with this telescope and try to get images of the planets, or someday just to get 6" or 8" SC telescope, if I can spend money ?

I like "Observing is a skill and you learn it by practice"! As newbie it is hard to understand it completely, but I believe you are right and will follow your advice. Actually I have few cheap eyepieces, and before order anything else, I will try them.

Thanks for the photos with the camera!

About the filters - I am living in a city with lot a light pollution, but my home place is in the yellow-blue zone. But will probably think about LP or UHC at first place.

Best regards!

[vlaiv]

1 hour ago, Miroslav said:

Last night when I post my topic I was sleepy and miss something to mention. First I recently understand that when view DSOs they looks black and white because of this I will be happy to can see the biggest of Messiers like Andromeda, Lagoon nebula and Pleiades. So my real plan is get good enough photos of them. And thinking of this I again ask myself - is a small refractor telescope (ED80 or ZS73) be a better option? Yes they are more expensive, but also smaller and probably better for AP. If viewing experience over some of those refractor would be same, may be it will be better to get one of them?

I have 80mm APO scope for astrophotography, and you can't go wrong with that.

It is this one:

https://www.teleskop-express.de/shop/product_info.php/info/p3881_TS-Optics-PHOTOLINE-80mm-f-6-FPL53-Triplet-APO---2-5--RAP-Focuser.html

One I have is very good scope, and is excellent astrophotography scope - wider field one. However, 130PDS will have significant edge visually - both on DSO and on planets.

This is actually very hard to give advice on - should you go for 80mm scope or stick with 130PDS.

130PDS is a bit more "all around" focal length at 650mm. ~80mm APO, paired with field flattener / reducer is more 350-400mm focal length - it is really getting into wide field rather than all around.

With refractor - it is all about simplicity - just put camera on and shoot. Newtonians are bigger and more susceptible to wind and there is collimation, and are often mechanically less rigid (focuser can be tilted for example) and so on. But 130PDS is very nice imaging scope - there are a lot of nice images produced with it - there is a whole thread here on SGL dedicated to that scope and images people produce with it.

Here is best I can do to help you decide:

- 130PDS will have edge on visual and be more general imaging scope while small apo will be good wide field instrument for both observing and imaging

- If I was choosing for myself as first scope - I'd go with 130PDS

- If I'm advising complete novice - I'd say go with 70-80mm APO (there is a lot to learn and master in imaging and if that is your main goal - and it looks like it is - then go with that scope).

[Miroslav]

Reading at the forums I am not the only one with this dilemma

I also checked the topics with the images from ED80 and 130PDS. I was surprised to see lot of planetary images, there few great of Jupiter with ED80. I didn't expect it. I thought 130PDS is better for the planets because of the bigger aperture, but looks like I was wrong...

And what about observing? Who of the both telescopes offer better viewing experience? I am asking, because have a kids and they will want to view something and will not wait me to shoot then process images.

I know TS telescopes, but they are too expensive. If I decide to go with a refractor I will probably get ZenithStar 73.

Regards!

[vlaiv]

130PDS offers better view visually - images will be brighter and there will be more details on the planets / moon.

Only issue with it is that it is newtonian type telescope and you'll be using it on EQ mount. Not the best combination.

As mount tracks across the sky - eyepiece will end up in very strange positions and you'll need to constantly rotate the telescope in tube rings to make eyepiece accessible.

Newtonian is much better suited to alt az type mount.

What's your budget? How about getting two scopes?

I know that this sounds silly - but why not go for 130mm collapsible newtonian on dob mount. This telescope is much more suitable for children to use:

https://www.firstlightoptics.com/reflectors/skywatcher-heritage-130p-flextube.html

That way you can have good scope for visual and still get APO to do astrophotography with?

[Miroslav]

Thanks again for the good points you mentioned.

Getting two telescopes is not bad idea. Reading here and there, all people mentioned there is not one-for-all telescopes. I thought for Dobson on alt-az mount, but with them there there is an image rotations and probably later is harder to stack the photos. Or this is not so big problem?

Is there Heritage with goto?

Also when I and the kids watch we will not spend whole night, so hope the eyepiece will not move too much But stil will have to put the eyepiece at some good beginning point so I can reach it most of the time... Never though about this...

My idea was to start with HEQ5 mount and get something for photos and use it for visual also. Later if I like this hobby and spend money would get something like Dobson or SCT for better view of planets and small DSOs eventually for imaging also.

Watching the prices of HEQ5 and 130PDS I hope to spend not more than 2k Euro at first place. I know if go to ZS73 the money will be more. Getting the mount, telescope, comma corrector, the camera adapters, may be a filter or an eyepiece and my budget will gone. The good new is I am not in a hurry, I will not watch during the winter.

Regards!

[vlaiv]

1 minute ago, Miroslav said:

I thought for Dobson on alt-az mount, but with them there there is an image rotations and probably later is harder to stack the photos. Or this is not so big problem?

Don't even think about alt-az or dob mount for AP if you are serious about it.

In principle - you can use very short exposures like second or two - to do very basic astrophotography with driven alt-az mount - but that is for very basic images.

For anything more serious than that - you want EQ tracking mount. Even simple star tracker will be more rewarding for someone starting into AP than alt-az mount.

3 minutes ago, Miroslav said:

s there Heritage with goto?

There actually is, it is very recent addition:

https://www.firstlightoptics.com/heritage/sky-watcher-heritage-150p-flextube-virtuoso-gti.html

That is 150/750 newtonian with motorized alt/az mount and goto capability.

5 minutes ago, Miroslav said:

My idea was to start with HEQ5 mount and get something for photos and use it for visual also.

HEQ5 is very nice AP mount and more than capable mount for visual.

I have HEQ5 - and almost never use it for visual. For visual I have simpler mounts. I use dob mount for my 8" dobsonian, and Az4 mount for smaller refractors. I much prefer simpler manual mounts for observing then setting up heavy EQ type mount for that.

In reality - you can get very capable visual scope for small amount of money and even basic AP setup is going to cost you much more - like x4-5 more than that.

Have you considered purchasing second hand items? That way you can save some money?

[Miroslav]

I know the AP is expensive. But I am sure, if I get for example an Heritage and like it, later I will still go to the AP That is why I try to choose between about 80mm ED refractor and 130PDS - an cheaper alternative. As I know for those two relescopes HEQ-35 is also an option, but what if later decide to upgrade the mount...?

Second hand items is good idea, but I do not know shop to offer used items. Do FLO offer? Because those are expensive and precise optics I would check offers form some astro-shop. I also have to check again into local forums what is the situation with old items.

Anyway at the moment looks like 130PDS is better for my needs

[vlaiv]

4 minutes ago, Miroslav said:

Do FLO offer?

FLO has section on returned items - check it here:

https://www.firstlightoptics.com/offers.html

They usually give 10% for customer returns and refurbished items.

Check out your local forums as well. Don't know where are you from - but you might have something on offer there (in my country there is relatively small astro amateur scene so second hand items don't come by often). With second hand items, it is nice that you might be able to try it out and make sure everything is all right (I guess that depends now on active C19 measures).

10 minutes ago, Miroslav said:

Anyway at the moment looks like 130PDS is better for my needs

How good are you with DIY?

Maybe you could build small dob mount like this one:

https://www.astroshop.eu/alt-azimuth-without-goto/omegon-mini-ii-dobsonian-mount/p,53648

(this actual mount is too small to hold the scope like 130PDS - but just to give you idea - all you need is couple of pieces of plywood / MDF cut to shape, bearings, some PTFE pads and one vixen clamp).

[Miroslav]

I checked the offers and will keep an eye on them.

For DYI I do not have place and tools at the moment, so will pass

Thanks for all help, and because I am not in a hurry I will checking the prices in FLO and in astroshop.eu. Because I am from Bulgaria the shipping from UK can be expensive.

Regards!

[malc-c]

Just want to chime in here.  Stick with the HEQ5 mount.  I would suggest that a 150PDS would be the nice sweet point of aperture vs stability.  Yes even entry level AP isn't cheap... but as Vlaiv has mentioned, the mount is the most critical component in AP.   There is no point in putting expensive ED refractors on a cheap mount that lacks the stability, and the precision a decent mount has to offer.  The HEQ5 has for a long time been recognised as the entry level AP mount.  It had finer microstepping and resolution in the gearing.  It's fully goto and thus makes it suited to autoguiding using software on a laptop.

If you are in the EU have a look at Telsckop Express  HEQ5 mount is 1021 Euro and the 150 PDS is 318 Euro, so around 1350 euro for the set up, and being within the EU it may make shipping and tax  - Shipping seems to be between 17 and 44 euro to your country.

One thing that a lot of people have found out that there is no one scope fits all, and this is why a lot of serious enthusiast have two or more set ups between a fixed imaging rig in the garden, a small portable visual set up, and a large refractor for planetary work... 

[Miroslav]

Thanks!

HEQ5 is my choice also in case later get something bigger.

A question about 150PDS - some people said it catch too much wind, is it so much bigger than 130PDS?

Also playing with fov calculator site probably I will need reducer if I want to fit Andromenda like DSOs in a single photo.

Regards!

[Miroslav]

Another question - lot of people mentioned autoguiding. I though the mount can follow the objects without need of additional software. Can I do AP with mount only?

And what about Celestron Advnaced VX mount?

Regards!

[vlaiv]

6 minutes ago, Miroslav said:

A question about 150PDS - some people said it catch too much wind, is it so much bigger than 130PDS?

It is a bit bigger and yes, it catches wind a bit more, but its both issue and not an issue - depending on how you look at it.

HEQ5 can mount much bigger scopes:

Yep, that is HEQ5 with 1.2 meter 8" newtonian that weighs around 11Kg - by itself with 1Kg guide scope + guider and camera and mount rings - all approaching max capacity of the mount.

I needed 15Kg of counter weights to balance it all - and yes, it did manage to produce image:

however, above setup is not something I would recommend (to anyone, let alone someone just starting out).

By comparison - both 130PDS and 150PDS are small, short scopes. Yes, 150PDS will catch a bit more wind - on a really windy day, but if day is windy - even 130PDS will have some issues.

You can overcome that by putting mount / scope somewhere that is shielded from wind - or just avoiding to shoot on nights where wind is 6+ m/s

12 minutes ago, Miroslav said:

Also playing with fov calculator site probably I will need reducer if I want to fit Andromenda like DSOs in a single photo.

Very few scopes can capture Andromeda in a single go - you need wide field scope to properly frame it.

That does not mean that you can't take a photo of it. There is something called mosaic technique. You take two or four images of different parts of target and you put those together to create final image

I could not fit whole M31 on my sensor with 380mm FL scope (80mm f/6 reduced to x0.8):

but I was able to make wide shot of M42 with very small sensor (guide camera really) - by making 3x3 mosaic (this version clearly shows pattern as I did not take flats and dust shadows show nicely):

Btw 150PDS will also beat both 70-80mm APO and 130PDS on visual targets as well.

[900SL]

All mounts like HEQ5 have errors in manufacture (like mechanical watches) so there is wobble and movement in tracking. Some are better than others. Also if mount not accurately polar aligned then stars will drift in position over time 

HEQ5 will have some periodic error, amount is variable depending on tolerances. 

Guiding uses a small guide scope and software to compensate for wobble. Adjustments are sent to the mount to keep it accurately on target stars

You can do AP without guiding if your focal length not too great, your polar alignment is good, your periodic error in mount is acceptable, and your length of exposure not too long.

 

  

  

[The Lazy Astronomer]

1 minute ago, Miroslav said:

Another question - lot of people mentioned autoguiding. I though the mount can follow the objects without need of additional software. Can I do AP with mount only?

And what about Celestron Advnaced VX mount?

Regards!

You don't have to guide, but it will help when doing long exposures.

When properly aligned, the mount will track the object through the sky, but it will not be capable of doing it with the precision required for long exposure astrophotography.

Depending on the setup, you'll probably find that without guiding, you'll only get somewhere around 60 seconds before you get star trailing in the image. With guiding (assuming it's all set up correctly), you should be able to expose for many many minutes without a problem. 

Guiding also allows you to add in a technique called dithering, where the telescope+camera are moved by a few pixels every so often - this helps to remove anomalous pixels from the final image when the data is later stacked (with appropriate clipping algorithm)

[ONIKKINEN]

Resist the urge to get the bigger newtonian for astrophotography. I have an 8 inch newtonian on an EQM-35 (and dont buy the EQM35 for any payload) and it has been nothing but trouble since day 1. While it technically has worked for several projects i would never recommend anyone do the same as its very frustrating. If i had gone for a more reasonable payload like a 130PDS i would actually have more usable exposure even relative to the aperture differences because i would have lost less to the elements. I estimate that only around 20% of my time spent outside with the telescope actually gets put in a stack in the end and that is considering that at one point i decided to only shoot at very high declination targets to make the mount behave better.

[vlaiv]

8 minutes ago, Miroslav said:

Another question - lot of people mentioned autoguiding. I though the mount can follow the objects without need of additional software. Can I do AP with mount only?

And what about Celestron Advnaced VX mount?

Regards!

These days autoguiding is really a norm - everyone who is serious about AP is doing it.

Mount can track the sky - but mounts are not perfect. Even very expensive mounts have imperfections in mechanical parts - parts that need to be round are not really round - they end up being "egg shaped". This can't be seen by naked eye or felt - but it shows up as periodic error in tracking. Mount can't hold star steady - in single place for a long period of time.

Look at this recording of my HEQ5 over an hour without guiding:

(it is sped up of course).

Up / down motion is due to periodic error in gears that drive the mount. Left to right motion is due to poor polar alignment.  Each of these two limit how long you can expose before star trailing becomes an issue.

If you want to image without guiding - you can, but you need mount with good absolute encoders, and these cost as much as whole Heq5 to be added to a mount.

For example iOptron CEM26 costs about £1000 in basic version:

https://www.firstlightoptics.com/ioptron-mounts/ioptron-cem26-center-balanced-equatorial-goto-mount.html

but same mount costs £2000 with encoders:

https://www.firstlightoptics.com/ioptron-mounts/ioptron-cem26-ec-center-balanced-equatorial-goto-mount-with-encoders.html

Auto guiding is much cheaper than that (even if you don't have laptop - you can use raspberry pi to control the mount and guide and control that with your smart phone).

Also note that autoguiding is something that you can add later on. You can start by simply doing shorter exposures like 30s to a minute and discarding some of your frames if they show excessive trailing in stars. That will get you going and you'll be able to learn basic steps in imaging and processing and later you can add auto guiding to improve performance.

I'm not sure what to say about AVX. Haven't used it, haven't read much about it. If you think it will provide you with better tracking performance without the need for auto guiding - it won't. Very few mounts are capable of tracking without guiding and all are expensive

[vlaiv]

7 minutes ago, The Lazy Astronomer said:

Guiding also allows you to add in a technique called dithering, where the telescope+camera are moved by a few pixels every so often - this helps to remove anomalous pixels from the final image when the data is later stacked (with appropriate clipping algorithm)

Well if you don't guide - you get "natural dithering" due to mount PE and PA error, so no bonus there really

[malc-c]

Just to throw in a few curve balls... Skywacher mounts are more supported when it comes to interfacing the mount to a computer.  An EQDIR cable to replace the handset, EQMOD or GSServer to act as the software "driver" and ASCOM compliant so communications between other applications is normally seamless.  It is possible to do the same with Celsetron mount, but you have to use their own software, and if memory serves me correctly (and If I'm wrong, stand corrected) need connection via custom serial cables via the handset.  - I think it is for these reasons that SW mounts seem to be the more common when it comes to entry level imaging rigs.

The HEQ5 can take a 200P, although if in exposed areas will have more impact on windy nights, but that doesn't me a 150 or 130 PDs would not be affected, they would, but to a lesser extent.

With imaging you take multiple exposures and stack them to give the equivalent of one long exposure.  Now even though the HEQ5 is circa £1000 it is in no means a precision mount.  It's mass produced to a price point.  It has errors in the gearing, lacks encoders, and has bearings lacking fine tolerances.   But all this is inside the specification that the mount is built to.  If you want a mount with better pression, encoders and tighter machining tolerances then you're moving up to the next class of mount and paying £4000 an up.  Even with precise polar alignment as mentioned, an HEQ5 will last around 40-60 seconds before PE creeps in and stars trail.  Now you could take 300 x 30 second exposures and stack them, but you may not get the same results  as stacking 30 x 5min exposures, which is why guiding is really essential these days.  Guiding helps compensate for the imperfections in PE and machine intolerances (well to a degree).

 

[Miroslav]

Thanks again guys!

It is good to know what I will need! So at the moment configuration HEQ5 and 130PDS looks good for me. Later will see.

About the giuding Vlaiv mention about using Raspberry. It sound great because I own RPi3. My laptop is old and if I can spend money from additional computer module will be good. Vlaiv, can you give me some directions about using RPi for guiding?

Also is the guidescope much different from the findscope or I can use the 130PDS finderscope, for example, as guider?

If I read correctly I will need some kind of camera for the guider, what type is it?

Probably I will need also power supply for all this gadgets?

Regards!

Edited December 9, 2021 by Miroslav

[vlaiv]

31 minutes ago, Miroslav said:

About the giuding Vlaiv mention about using Raspberry. It sound great because I own RPi3. My laptop is old and if I can spend money from additional computer module will be good. Vlaiv, can you give me some directions about using RPi for guiding?

I think there are couple of options available.

There is astroberry:

https://www.astroberry.io/

then there is IndigoSky (I've started using that one for my remote / backyard wide field setup - rpi4 and controlled from desktop in my study):

https://www.indigo-astronomy.org/indigo-sky.html

I think that you can also install regular linux distribution onto RPI and use PHD2 guiding software under linux via remote desktop for example.

Even if your laptop is old one - it should be ok for basic guiding and imaging tasks. I used laptop with old intel celeron dual core processor and if I remember correctly 4GB of ram when I first started out. It was enough to do both planetary imaging (it had USB 3.0 port) and regular imaging + guiding.

40 minutes ago, Miroslav said:

Also is the guidescope much different from the findscope or I can use the 130PDS finderscope, for example, as guider?

Yes you can - there is adapter that will turn 9x50 finder scope into guide scope with camera attachment - like this one:

https://www.firstlightoptics.com/finders/astro-essentials-sky-watcher-9x50-finder-to-c-adapter.html

Not sure if there is such adapter for 30mm finder - but if you have 3d printer, I'm sure you'll be able to print suitable adapter.

43 minutes ago, Miroslav said:

If I read correctly I will need some kind of camera for the guider, what type is it?

You can use dedicated guide camera or even use web cam converted to guide camera role.

All you need to do is make nose piece attachment of some sorts and remove lens from web camera. I made one from Logitech c270 camera - which I used for planetary imaging back then. I used 40mm PVC pipe that I sanded down to fit into 1.25" focuser.

Alternative is to get dedicated guide camera like this one:

https://www.firstlightoptics.com/guide-cameras/zwo-asi-120mm-mini-usb-20-mono-camera.html

or if you don't mind ordering from AliExpress, then maybe something like this (much cheaper - but closer to web cam):

https://www.aliexpress.com/item/32868532770.html

51 minutes ago, Miroslav said:

Probably I will need also power supply for all this gadgets?

Yes, a lot of 12V 3A adapters

(I have 3 of those - one for mount, one for cooled camera, one for flat panel, although I sometimes use one for mount for taking flats after I part my mount and turn it off).

Some people prefer batteries, especially if they have mobile setups. You can look into lithium batteries (best are LiPoFe4 type) or lead-acid deep cycle (cheaper and greater capacity but heavier).

[Miroslav]

Thanks, Vlaiv!

I will read next days about Astroberry  and Indigo to try understand the difference and possibilities. Also will check for PHD2 Linux Arm version.

The problem with my laptop is its battery gone long time ago and I use it as desktop. Also I no need another laptop so will no buy new.

Looking at the camera in Ali - the reviews are all positive. But let me first get familiar with the software. I am sure I will need more help in near future and will write and ask again.

Regards!

[malc-c]

The options of what to use at the heart of the scope control have all been discussed before on the forum, there is a wealth of information from DIY systems using pi's or arduinos, NUC pcs, and laptops , up to "custom" astronomy PCs from leading camera manufactures.  Again it depends on your budget vs convenience.  And then there's the choice of windows / ASCOM or Linux / INDI route of control.  The good news is a search of this forum should throw up the info you need, at least to get the basics.