#Finally making the leap...

45 messages · Page 1 of 1 (latest)

viral ginkgo
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I decided to get into this whole astrophotography hobby several years ago and then dropped it after I had moved. Now, I'm back, and want to get going. I have a QHY268 and CFW3 w/ filters that I had purchased back then; that's where the story ends. My goal is to create some cool DSO images, nothing specific beyond that. I live in a lovely bortle 8.2 zone, but can drive frequently and camp in a 2.5 zone, so it'll be a portable-ish setup that I am leaning toward. I know the mount is heavy, but it's not too heavy for my aspirations, I think. What say you about this plan... any suggestions, something I am missing, or alternatives to consider? Budget is about $5K USD, would go to $6K if there was a good reason.

What I'm thinking of:
EQ6-R Pro
Askar FRA500
WO 50mm Uniguide
ZWO ASI120mm Mini

visual epoch
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saves money

viral ginkgo
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Maybe something like the Apertura CarbonStar 150? I am a bit surprised by how inexpensive these are, heh.

visual epoch
visual epoch
pine nexus
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If you were to go the newt route then I'd look for something around 200mm aperture, they are pretty much ideal for the mount. Whilst not static, I'd struggle to call it portable.

visual epoch
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i mean ive got the 200mm on a heq5 so i feel a eq6r could pull more and be fine

somber comet
# viral ginkgo Any particular 10" f/4 you had in mind? 10" seems like it would probably be a bi...

Not even close to too heavy for the mount. The EQ6R can handle it no problems at all. I hear the same regularly about the 8" f5 on the HEQ5 and it is handled absolutely perfectly. If you could get your hands on a Quattro 250cf (the carbon tube version) that would be my pick (this is my current rig), they're substantially lighter than the regular quattro 250p. If you can fit it in your car, it's definitely portable. You just need to be practised at setting up and organising to make it efficient and not feel like a task.

somber comet
hot wasp
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it uses quite a bit of the EQ6-R's capability and its getting there, but it for sure isn't too heavy

somber comet
hot wasp
somber comet
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This is a commonly spread piece of misinformation and old tropes about mounts. Payload is mostly a myth as it does not take in to account the inertia and moment arm of the system

hot wasp
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Mainly due to external factors

somber comet
hot wasp
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I am saying that it uses the EQ6-R decently,

somber comet
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The 50% statement about payload limit for imaging has consistently been proven a myth

pine nexus
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I think people opinions differ partly because their environmental conditions differ. I know poptart was running an 8" on a beltmodded HEQ5 and it really struggled for "grip", he moved to the EQ6R and saw pretty huge improvements. Darren was running a 250pds on a EQ6R and he too struggled with wind at times.

hot wasp
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Im just saying that "not even close" just isnt right

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Its not pushing the EQ6 to its limits but its getting close-ish to there

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"not even close" would rather be an 8'' F/5, no?

somber comet
hot wasp
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The theoretical weight limit and the practical limit are two different worlds, yes the EQ6r can handle a lot of weight, but that might not hold true with a gigantic tube like the 10“ considering e.g. wind

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I can agree that the weight alone doesn’t come close to the limit but considering the tube and balance, I would say it’s more close than not

somber comet
# hot wasp Elaborate

The important factor is inertia and the moment arm (can be read as leverage) on the system. More mass extended further from the axis of rotation is a more important consideration. If the centre of balance is very close to the geometric centre, the system requires less power, and has more in reserve for corrections.
Now wind is a different consideration again as all systems are affected by wind. But, wind without a metric is subjective. I might call 20kph windy, you might call it a light breeze.

hot wasp
somber comet
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It's also why it's better to have more counter weight closer to the axis of rotation than it is to have less mass but with a counterweight bar extension. Corrections with guiding require rapid response, and when the mass is further from the centre, it takes longer for that mass to accelerate and change it's position, but importantly to also stop and not overshoot

viral ginkgo
viral ginkgo
somber comet
somber comet
# viral ginkgo Is the carbon tube even made/sold anymore? I am not seeing any except on one sit...

The CF quattro's stopped a few years ago, but they pop up from time to time second hand if you're not in a rush (hence my caveat earlier). The regular p series quattro's are perfectly good also, just a bit heavier, but still within reason.

I would say though, that the f5 pds scopes are also perfectly good, they just require a little tinkering to get them to punch above their class, but are less collimation sensitive than the quattro. Flock the tube (or install some baffles), throw on a mirror mask, and it will be sharp and have decent contrast with good collimation.

viral ginkgo
somber comet
# viral ginkgo The P series, you think would be fine on the EQ6-R? I do worry about the whole p...

Essentially yes. So as I discussed with firehdn above, the important factor isn't really the weight of the imaging system on the mount. The old advice is to not exceed 50% of the payload limit of the mount. The problem with that advice, is that it doesn't take into account the inertia of the system and the moment arm.
So the limit for imaging is a bit of a grey area. I know quite a few people imaging with the 10" p series quattro successfully on an EQ6R, one of which is an award winning astro photographer.
If the mount is tuned well and running as well as it can, the guide settings are good and polar alignment is very good, they can handle it.
But, I will also say, that using a large telescope like a 10" quattro, isn't very friendly to someone that hasn't imaged with fast newtonians before.
Even an f5 8" will require quite a bit of learning and "time on the tools" to understand how the system works and how to get the most out of it. But if you like a bit of a challenge, you like tinkering and you're willing to put in the time, you can get amazing results

viral ginkgo
somber comet
# viral ginkgo I appreciate this explanation, thank you. I am indeed someone who enjoys picking...

No problem at all. Always happy to help out. Newtonians can be quite daunting with no experience, but are underappreciated and powerful telescopes for their price point. They're not as set and forget as refractors, but can definitely hold their own with the right touch.
The 1000mm mark is a very nice place to be with a APSC size sensor like the imx571. It's also worth noting, that if you do want to reduce the weight down the line, carbon tubes can be purchased to replace the steel tube, and you'll have some added rigidity as well.

viral ginkgo
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It has been done! Ordered the scope, mount, and coma corrector for $3500 (USD) including taxes and shipping. Significantly under that budget I had in mind, heh.

visual epoch