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Advice on buying a portable mount


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Hello guys, I am new to this hobby and now considering to get a serious eq mount for some DSo photography.

i ordered a c5 and its on its way, I also own a canon 70-300mm.

I’m  aware that c5 isn’t a good scope for DSo, but it should be able to get some decent results, I would be mostly using the 300mm lens and sometimes the c5.

since I don’t have a car, I’m looking for a mount which is portable but accurate enough to track. 
I am considering the eq3 pro and cem25p, but some said it could only give acceptable results up to 600mm, so not suitable for c5? Is it also not that good?

thanks in advance! 

Edited by Bc0428
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I would have a look at the EQ3 DSO imaging thread to see what is possible.

The C5 will be fine for planetary and lunar imaging on it, but even with a focal reducer is a bit long for an EQ3-2 for DSO imaging I would guess. The 300 mm should bpose no problems. I regularly shoot at 384mm on the EQ3-2 I have

 

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30 minutes ago, michael.h.f.wilkinson said:

I would have a look at the EQ3 DSO imaging thread to see what is possible.

The C5 will be fine for planetary and lunar imaging on it, but even with a focal reducer is a bit long for an EQ3-2 for DSO imaging I would guess. The 300 mm should bpose no problems. I regularly shoot at 384mm on the EQ3-2 I have

 

I guess most awesome work is done by the experienced, so if the eq3 is not that newbie friendly(especially me and my c5), I might not achieve those quality very soon... so im looking for something more accurate. How about the cem25p? Is it good enough?

 

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4 hours ago, Bc0428 said:

I guess most awesome work is done by the experienced, so if the eq3 is not that newbie friendly(especially me and my c5), I might not achieve those quality very soon... so im looking for something more accurate. How about the cem25p? Is it good enough?

 

I don't know the CEM25P, but I should add that my contributions to the thread I quoted did not stem from a huge amount of imaging experience (except in planetary, lunar and solar, but no DSOs). My first efforts with a 200mm lens on the EQ3-2, without guiding, just tracking were theseM31-07012018-2re2.thumb.jpg.9ef8fa772b6b211bdd396d9f641a0c68.jpg

Rosette08012018LPremBGcal.thumb.jpg.8fd0087100646362ac475a880f9e724f.jpgOrion07012018LPremBGcal.thumb.jpg.528712ac47c046ad292edddfc57ee3f6.jpg

I used lots of short subs and stacked them in Astro Pixel Processor, did some postprocessing in t he same, and then tweaked with Gimp

My first attempts with the 80mm F/6 triplet and 0.8x focal reducer were these:M45-21625.0scrop-curves.jpg.ee7f5d5014cf53e9ed4e4819b64692ea.thumb.jpg.98f94fe68613e7ea708b2e6e8e20931d.jpg

M31-8762s-c2.thumb.jpg.ae173b86ab4652dd2cc927e3b033158f.jpg

M42-25891.0s-crop-curves.jpg.e9d99e6179329b043d2d215548abe141.thumb.jpg.2bceb79d5bfc07cdbcdb306b15146540.jpg

The latter is a 7 h 11 min stack of data, captured over three nights (more data are needed ;)). All were done from my suburban back garden (Bortle 5 at best), using a modded Canon EOS 550D. Patience is needed more than experience, I feel.

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Absolutely gorgeous!!!😍 the eq3 doesn’t seem that poor after all 

I got very negative feedback about it from other forums...

how short was these subs? Say 30 secs? I envy your bortle 5 skies... it should be challenging for my bortle 8 skies...

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7 minutes ago, Bc0428 said:

Absolutely gorgeous!!!😍 the eq3 doesn’t seem that poor after all 

I got very negative feedback about it from other forums...

how short was these subs? Say 30 secs? I envy your bortle 5 skies... it should be challenging for my bortle 8 skies...

EQ 3 is good for basic astrophotography. 30-sec subs should be doable.

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If you want the absolute most portable, affordable, and compact mount for imaging that can track and has GOTO then a Skywatcher AZ-GTi with a wedge will be a good option. Especially using just your DSLR and lens. Here is a thread where it is discussed:

If you want something still portable but more robust yet still affordable (that is a relative term in astro photography [AP] circles) then the best option would be the Skywatcher HEQ5. If you are considering an iOptron mount, including the CEM25, I would suggest doing some extensive research first. Some get great mounts that perform really well. Others do not and end up putting their mounts in the bin in frustration.

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1 hour ago, Dr Strange said:

If you want the absolute most portable, affordable, and compact mount for imaging that can track and has GOTO then a Skywatcher AZ-GTi with a wedge will be a good option. Especially using just your DSLR and lens. Here is a thread where it is discussed:

If you want something still portable but more robust yet still affordable (that is a relative term in astro photography [AP] circles) then the best option would be the Skywatcher HEQ5. If you are considering an iOptron mount, including the CEM25, I would suggest doing some extensive research first. Some get great mounts that perform really well. Others do not and end up putting their mounts in the bin in frustration.

I’m not sure if it could handle my c5 even with a focal reducer, so I didn’t consider it

it seems cem25p is capable of it, just like to know roughly how much time I got in each sub for a c5 with 0.63x reducer on cem25p?

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6 hours ago, Bc0428 said:

I’m not sure if it could handle my c5 even with a focal reducer, so I didn’t consider it

it seems cem25p is capable of it, just like to know roughly how much time I got in each sub for a c5 with 0.63x reducer on cem25p?

I wouldn't know that exactly, but you would need to guide. With focal reducer the C5 has a focal length of 787 mm, fairly close to my 6" Schmidt-Newton at F/5 (762 mm). I use a Vixen GP-DX mount for that, and purely with tracking (not autoguiding) you cannot go much beyond 30s (granted, the ASI183MC I use has small pixels, which demands higher accuracy than the larger pixels of a DSLR).

I would simply use the C5 for planetary and lunar imaging, and use the 300mm for DSOs. You could always add a short refractor to your kit later to go after smaller DSOs

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12 hours ago, Bc0428 said:

I’m not sure if it could handle my c5 even with a focal reducer, so I didn’t consider it

it seems cem25p is capable of it, just like to know roughly how much time I got in each sub for a c5 with 0.63x reducer on cem25p?

The rule of thumb for a non-premium mount (Mensu, 10 Micron, Astro-Physics, Paramount, Losmandy) is to take the rated payload capacity and divide it by 1/2. The Losmandy GM811G is close to 100% rated weight. The other premium mounts I mention are. They state the rated imaging weight. The non-premium mounts state the maximum payload for visual use save the CGX which claims to be the rated imaging weight. In my own experience with the CGX I would say 75-80% not 100%. 

I have not seen reports that the iOptron mounts are at this level. So I am not sure. But based on what I know of the CEM25 from reports I have read I would be hesitant to apply the 75-100% rule. I would be using the 1/2 rated weight rule. However I think the CEM60 and 120 are in the 75-100% range. But that doesn't do you any good. I mention it just for reference. 

From what I found the CEM25 has a rated max payload of 12.24kg. The C5 per Celestron is 7.98 kg. This is over the 1/2 rule of thumb by almost 2kg. That is significant enough to be a potential challenge. It is likely you can image with the CEM25 but may face issues when you do. It would likely be better to go with the HEQ5 or AZ-EQ5. 

Alternatively for less money than you would spend on the HEQ5 or the AZ-EQ5 plus focal reducer you could buy the AZ-GTi, wedge, and the Skywatcher 72mm ED refractor. When starting out in imaging it is better to go with a short focal length refractor than a longer focal length reflector. AP is a very complex part of the hobby and adding more complexity via a focal reducer and a longer focal length reflector. The C5 is also workable for visual use on the AZ-GTi. Thus satisfying your requirement for compact, easy to transport, and still be usable. You can image with the AZ-GTi and 72mm refractor then use both the 72 and the c5 for visual on a very compact light weight mount. 

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15 minutes ago, Dr Strange said:

The rule of thumb for a non-premium mount (Mensu, 10 Micron, Astro-Physics, Paramount, Losmandy) is to take the rated payload capacity and divide it by 1/2. The Losmandy GM811G is close to 100% rated weight. The other premium mounts I mention are. They state the rated imaging weight. The non-premium mounts state the maximum payload for visual use save the CGX which claims to be the rated imaging weight. In my own experience with the CGX I would say 75-80% not 100%. 

I have not seen reports that the iOptron mounts are at this level. So I am not sure. But based on what I know of the CEM25 from reports I have read I would be hesitant to apply the 75-100% rule. I would be using the 1/2 rated weight rule. However I think the CEM60 and 120 are in the 75-100% range. But that doesn't do you any good. I mention it just for reference. 

From what I found the CEM25 has a rated max payload of 12.24kg. The C5 per Celestron is 7.98 kg. This is over the 1/2 rule of thumb by almost 2kg. That is significant enough to be a potential challenge. It is likely you can image with the CEM25 but may face issues when you do. It would likely be better to go with the HEQ5 or AZ-EQ5. 

Alternatively for less money than you would spend on the HEQ5 or the AZ-EQ5 plus focal reducer you could buy the AZ-GTi, wedge, and the Skywatcher 72mm ED refractor. When starting out in imaging it is better to go with a short focal length refractor than a longer focal length reflector. AP is a very complex part of the hobby and adding more complexity via a focal reducer and a longer focal length reflector. The C5 is also workable for visual use on the AZ-GTi. Thus satisfying your requirement for compact, easy to transport, and still be usable. You can image with the AZ-GTi and 72mm refractor then use both the 72 and the c5 for visual on a very compact light weight mount. 

Emm... from what I know c5 should be only 6 pounds(~3kg), adding a DSLR and accessories should weigh less than 5 kg I guess. 

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6 hours ago, michael.h.f.wilkinson said:

I wouldn't know that exactly, but you would need to guide. With focal reducer the C5 has a focal length of 787 mm, fairly close to my 6" Schmidt-Newton at F/5 (762 mm). I use a Vixen GP-DX mount for that, and purely with tracking (not autoguiding) you cannot go much beyond 30s (granted, the ASI183MC I use has small pixels, which demands higher accuracy than the larger pixels of a DSLR).

I would simply use the C5 for planetary and lunar imaging, and use the 300mm for DSOs. You could always add a short refractor to your kit later to go after smaller DSOs

Any recommended guiding camera that is small and cheap which could be used on the c5 stock finder scope? I’m low on budget after buying a bunch of equipments at the same time...

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51 minutes ago, Bc0428 said:

Emm... from what I know c5 should be only 6 pounds(~3kg), adding a DSLR and accessories should weigh less than 5 kg I guess. 

Not sure why I saw it so heavy. I was confused by it but it was from Highpoint Scientific so I thought it was reputable. 3kg sounds MUCH more realistic! My mistake. Sorry about that! 

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2 hours ago, Bc0428 said:

Any recommended guiding camera that is small and cheap which could be used on the c5 stock finder scope? I’m low on budget after buying a bunch of equipments at the same time...

Unless the model has changed, the stock finder scope of the C5 is not easily adapted to use as a guide scope, because it doesn't have a 1.25" EP barrel, so guide cameras don't fit easily. 

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7 hours ago, michael.h.f.wilkinson said:

Unless the model has changed, the stock finder scope of the C5 is not easily adapted to use as a guide scope, because it doesn't have a 1.25" EP barrel, so guide cameras don't fit easily. 

What if I replace the whole finder scope then? Any decent model will do?

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I'm going in a similar direction using the CEM25 using an off axis guider, a small prism which splits off part of the primary optical path, hence no finder scope.

FWIW my all up weight is ~8.5kgs.

Good luck

Best Regards

picclock

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5 hours ago, Bc0428 said:

What if I replace the whole finder scope then? Any decent model will do?

Any model listed as a finder/guider should work. An off-axis guider is available for Celestron SCTs, that would also be an option. Many planetary cameras are suitable as guide cameras, and can be used for lunar/planetary imaging as well. If budget is tight, look for e.g. a second-hand ASI120MC or ASI224MC. Colour is not needed for guiding, but certainly makes life easier for planetary imaging

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6 hours ago, michael.h.f.wilkinson said:

Any model listed as a finder/guider should work. An off-axis guider is available for Celestron SCTs, that would also be an option. Many planetary cameras are suitable as guide cameras, and can be used for lunar/planetary imaging as well. If budget is tight, look for e.g. a second-hand ASI120MC or ASI224MC. Colour is not needed for guiding, but certainly makes life easier for planetary imaging

Alright! One last thing, hope this isn’t a dumb question. Since I’m not sure how this guiding thing works, I don’t know how significant it is. Comparing a fair mount(star adventurer) with guiding and better mount(Cem25p) without guiding, which works better?

it seems guiding is essential but is it a real game changer that even compensates for the inaccuracy of mount? Thanks!

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