Please help - buying first imaging rig

[bosun21]

14 hours ago, Mr Green said:

If you guys think that the Star Adventurer GTi is a better option than the EQM35 to support an 80ED, I'll go with that as it's cheaper which is a bonus.

For a few pounds more (£700) you can buy an EQ5 Pro which is a better mount than the EQ35 and can be used as an introduction into AP. It will handle an 80ED easily. If further down the road you decide to get serious about astrophotography you can always sell it and upgrade to a heavier mount.

[Mr Green]

I thought that the EQM35 had a higher imaging capacity (7kg) vs the EQ5's 6.5kg.

I've seen YouTube videos advising that the Go-To functionality is poor on the EQM35 so guessing that's the reason why it's to be avoided? 

I'm a little confused as the EQ5's reviews aren't so good on FLO's website vs the EQM35....

Maybe II'll just stick with the Star Adventurer and SW 72ED as per the list I provided in my last message.

Any thoughts on my list would be appreciated.

[happy-kat]

The 35 being a mount gives visual capability if that's useful for you 

I've not used either mount.

[bosun21]

33 minutes ago, happy-kat said:

I

Edited October 19, 2023 by bosun21
Quoted wrong person.

[bosun21]

41 minutes ago, Mr Green said:

I thought that the EQM35 had a higher imaging capacity (7kg) vs the EQ5's 6.5kg.

I've seen YouTube videos advising that the Go-To functionality is poor on the EQM35 so guessing that's the reason why it's to be avoided? 

I'm a little confused as the EQ5's reviews aren't so good on FLO's website vs the EQM35....

Maybe II'll just stick with the Star Adventurer and SW 72ED as per the list I provided in my last message.

Any thoughts on my list would be appreciated.

The EQ5 uses actual bearings whereas the EQ35 does not. I’ve owned both and the EQ5 is a better mount and the go to works really well. 

[WolfieGlos]

Although I’ve not used either, I think ultimately you will be fine with either a GTI or EQ5, with the 72ed.

The problem with both mounts is that you won’t really be able to put bigger scopes onto them down the line (if you get the same bug that everyone else seems to get…I know I did!), but if that’s not an issue, then you’ll be fine.

It’s not a cheap hobby, but generally the rule of thumb is mount, mount and mount. Good luck!

[billy86]

For imaging galaxies would a 80mm apo with a dslr be good? 

[Elp]

Typically no, 99pc of galaxies are quite small. The 80mm will be okay on Andromeda and Triangulum (M101, Bodes, a few clustered galaxies like Markarians Chain will capture), but most others will be tiny, especially on a large DSLR sensor. It's not to say it's useless, this summer I did a nine panel mosaic with my Z61 and captured something like triple digits number of galaxies in the same image (tiny though they were).

Edited October 19, 2023 by Elp

[billy86]

12 minutes ago, Elp said:

Typically no, 99pc of galaxies are quite small. The 80mm will be okay on Andromeda and Triangulum (M101, Bodes, a few clustered galaxies like Markarians Chain will capture), but most others will be tiny, especially on a large DSLR sensor. It's not to say it's useless, this summer I did a nine panel mosaic with my Z61 and captured something like triple digits number of galaxies in the same image (tiny though they were).

Would you suggest a 8" newtonian and a dedicated astro cam?

[Elp]

Depends on a lot of factors, your experience and mount being a few. The longer FL you image the better your mount needs to be and autoguiding is pretty much essential, a Newtonian also acts like a wind sail so any slight breeze and there's the potential for a ruined sub, therefore the tripod also then plays a major role and needs to be sturdy. A Newtonian from my experience is second best in terms of clarity (quality glass apo refractor being first) but you'll struggle getting the FL with a refractor at a similar price. I think a refractor near 800-1000mm will do well but the F ratio goes up so does your total imaging time. If youre experienced a good tracking Newtonian or dob will work as their light gathering will be an advantage, or an SCT with a focal reducer but sharpness takes a hit in comparison to the above.

[Elp]

Have a look on astrobin and see what equipment people have been using to give you an idea.

[Mr Green]

Evening All,

I've decided to go with the SW 72ED, GTi mount, field flattener and a few other accessories including an ASIair bundle.

Order arrives on Saturday therefore fingers crossed we have clear skies.

I think that this will do me nicely to start with although went over budget.... whoops 

[billy86]

2 minutes ago, Elp said:

Depends on a lot of factors, your experience and mount being a few. The longer FL you image the better your mount needs to be and autoguiding is pretty much essential, a Newtonian also acts like a wind sail so any slight breeze and there's the potential for a ruined sub, therefore the tripod also then plays a major role and needs to be sturdy. A Newtonian from my experience is second best in terms of clarity (quality glass apo refractor being first) but you'll struggle getting the FL with a refractor at a similar price. I think a refractor near 800-1000mm will do well but the F ratio goes up so does your total imaging time. If youre experienced a good tracking Newtonian or dob will work as their light gathering will be an advantage, or an SCT with a focal reducer but sharpness takes a hit in comparison to the above.

This is all becoming more and more technical and very expensive the more I look into it. I've been looking at an NEQ5 maybe with the askar 103 triple apo 

[Elp]

Have you done AP before? An 80mm will be a good all rounder scope and likely a keeper, I think for small targets you'd need to go up to a 100mm but this depends largely on your expectations, I'm happy capturing a tiny galaxy spanning a few pixels with a camera lens knowing that a more professional setup or space telescope will be the only way to capture the same target in larger detail, but this is okay with me.

AP isn't cheap, it can be done on a budget but your expectations need to dial down with the budget. But it doesn't mean the result will be bad. Have a look at the Samyang 135mm forum, one of the largest on this site, who knew a 400 odd daytime camera lens (can be bought much cheaper used) could rival actual astronomy telescopes at a higher price point.

If you've never done AP before, start with a smaller setup, either with a DSLR/camera setup or a refractor setup. After a few projects you'll know it's strengths and weaknesses and what to look for next, trust me if you're in it for the long haul they'll always be the next purchase (hence another reason it isn't a cheap hobby).

Also look at the telescope simulator on Telescopius website and input any prospective equipment focal lengths and camera sensor sizes and look at the framing by searching for targets, this will give you an idea of what the prospective equipment will do. As a rough guide note any pixel imaging ratio lower than 1, maybe slightly higher is generally unachievable due to seeing requirements (and you need larger telescopes to image at higher resolution), that's how I interpret it anyway but the framing tool is spot on as I use it to plan all my sessions.

[david_taurus83]

14 hours ago, Mr Green said:

Evening All,

I've decided to go with the SW 72ED, GTi mount, field flattener and a few other accessories including an ASIair bundle.

Order arrives on Saturday therefore fingers crossed we have clear skies.

I think that this will do me nicely to start with although went over budget.... whoops 

Good shout with a small refractor to start with. I tried a 200P at first and quickly downsized scope and upsized mount!

Have you factored in guiding? It's a must imo if you want good early results. The ASIAir will take care of it for you so it's not as complicated as it used to be.

[Mr Green]

Guiding factored in, I should have been more specific when saying I ordered the ASiair bundle... I'll have the air plus, guide scope and mini camera arriving with the scope and mount.

The only thing I've not ordered are filters which I will probably need but I don't expect amazing results from the outset.

I'm also not too keyed up on back focus as I'll be using a DSLR with a flattener.

If I can't achieve focus or struggle with imaging in any way, I'll be sure to do more studying.... trial and error is all part of the fun! 

 

[WolfieGlos]

1 hour ago, Mr Green said:

The only thing I've not ordered are filters which I will probably need but I don't expect amazing results from the outset.

I'm also not too keyed up on back focus as I'll be using a DSLR with a flattener.

If I can't achieve focus or struggle with imaging in any way, I'll be sure to do more studying.... trial and error is all part of the fun! 

 

Is your DSLR a stock or modded camera? In either case, you shouldn’t really need a filter; stick to broadband targets to start with and it’ll produce decent images. If you have a modded camera it’ll also work well on emission nebulae as it is.

With the 72ed and DSLR, you’ll be able to achieve focus with no issue - by the way, have you got a bahtinov mask? It’s not 100% necessary but it will make it a lot easier to focus.

Backfocus is a different thing, I never managed to successfully achieve it with my 72ed, I got close but never successfully dialled it in so I gave up and cropped the edges off during processing. Backfocus should be 55mm - so just the flattener and the t-ring, but I got to around 63mm if I recall correctly.

[happy-kat]

To start you could make from card, compass and a protractor a Lord Y bahtinuv mask to help with focus.

[Elp]

A DSLR via tring should be pretty much bang on back focus wise, mine was first time but it depends on the optics. You don't really need a bahtinov if you've got the asiair, the in built focus routine is much more accurate as it provides realtime FWHM quantified values rather than visually assessing a focus pattern.

[Mr Green]

DSLR is stock but good to hear I should still get some decent results.

I don't have a Bahtinov mask, totally forgot to add one to my order so was going to try and focus as best as I could through the DSLR view piece and see how I get on.

If it's a struggle, I'll order one. Also need to order an LED light pad for taking flats but was going to try and wing it somehow..... blank white screen on ipad etc

[WolfieGlos]

Bahtinov mask isn’t essential but it does make it easier from the outset in my opinion.

I don’t have the ASIair, but as @Elp says, you can focus through the ASIair - I imagine it’s straightforward enough to save on buying (or making) a mask. @Elp does it work without an EAF? 

As for flats, even now I use a white T-shirt and the iPad, and I find it works fine for me. I use AV mode on the camera (with the same ISO), check the histogram and adjust the iPad brightness to suit. Try this to begin with whilst learning the ropes, and being mindful of budget, if you feel you need to spend more on a Flat panel then do so in due course 🙂

[Elp]

You can use the asiair focus routine manually, once your scope is reasonably focused you select a medium sized star from the starfield in the focus routine and the app zooms into that star, you then adjust focus until your FWHM is as reasonably low you can get it, it shows a real time graph of brightness and FWHM (I just use the latter) as well as digital numbers so you'll know when you're close, tinier stars will also appear in the starfield. With my SY135 or Z61 I usually get near 1 or sub 1 FWHM, C6 at 1000mm closer to around 2.5-3, it depends on the optics being used and seeing on the night. Take a few previews after and check the whole star field and you're done in less than 5-10 minutes. Using a DSLR, the updating is slightly slower than an astro camera due to the shutter mechanism, but the routine is much better than using dslr in built systems.

Edited October 21, 2023 by Elp

[david_taurus83]

I have a a Bahtinov mask for a 80mm refractor I no longer have. I'm sure it will also work with your 72ED so if you pm me your address I will send it to you FOC as I have no need for it. I get what Elp is saying above about using the Air but that can be time consuming with a DSLR. Best method I found for manually focusing my 6D is aim at a bright star, stick it in Liveview and focus with a Bahtinov mask. 

[Mr Green]

9 hours ago, david_taurus83 said:

I have a a Bahtinov mask for a 80mm refractor I no longer have. I'm sure it will also work with your 72ED so if you pm me your address I will send it to you FOC as I have no need for it. I get what Elp is saying above about using the Air but that can be time consuming with a DSLR. Best method I found for manually focusing my 6D is aim at a bright star, stick it in Liveview and focus with a Bahtinov mask. 

Very kind of you to offer, I'll drop you a pm if I struggle at all with focusing as I wouldn't want you going out of your way. Hopefully I'll manage although dec balancing the 72ed with the dslr attached is impossible!! Very weighted on backend but hoping I'll still be able to image as everything stays put when clutch is tightened.

[Elp]

Usually Ive found supplied dovetails are too short for imaging payloads, you may see your declination guiding graph be haphazard as a result. The easy solution is to buy a longer dovetail bar, or if it's long enough, mount the scope more to the front of it.