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Equipment Discussions >> Mounts

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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6360364 - 02/06/14 06:27 PM

Well, all the orders have been made for the interim mount.

Received my Orion Mini Autoguider + SSAG a few days ago.
Ordered an ADM Dual Side-by-side D-style saddle which should be here in a couple days.
Ordered an Astro-Tech Losmandy D-style dovetail plate which has a slit down the middle which will support dual-screw mounting to my 600mm lens, which should be here in a few days.

Finally, ordered a new Orion Atlas EQ-G mount today, which should be here in a couple weeks.

Hopefully this will get me rolling by the end of the month. Thanks for the help with the high end mounts guys. I have a pretty clear idea of what I want to do...just a matter of saving up the dough for it.


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6360374 - 02/06/14 06:30 PM

Quote:

Well, all the orders have been made for the interim mount.

Received my Orion Mini Autoguider + SSAG a few days ago.
Ordered an ADM Dual Side-by-side D-style saddle which should be here in a couple days.
Ordered an Astro-Tech Losmandy D-style dovetail plate which has a slit down the middle which will support dual-screw mounting to my 600mm lens, which should be here in a few days.

Finally, ordered a new Orion Atlas EQ-G mount today, which should be here in a couple weeks.

Hopefully this will get me rolling by the end of the month. Thanks for the help with the high end mounts guys. I have a pretty clear idea of what I want to do...just a matter of saving up the dough for it.




Good choice.


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: EFT]
      #6360432 - 02/06/14 07:03 PM

I had a round of emails back and forth with Celestron about the CGEM mount. The final verdict was they really don't support third-party autoguiders, at least, when it comes to correcting the known non-standard periodic errors inherent to their design. Celestron ONLY officially supports correcting their mounts inherent issues that with their own autoguider. Personally, I'm not a fan of it...it doesn't work with a PC, so you have to use this tiny little screen on the device to configure it. I'm also not real big on any device that tries to lock you into a vendor...especially with astronomy and astrophotography, you really need to be able to interchange components from different brands to get the best tools to serve your needs.

I couldn't get any info out of the guy regarding how well a CGEM would track with an Orion SSAG...and I finally gave up. The fact that the Atlas had a built-in dual saddle was also an added bonus, and saved me money in the long run (I won't have to spend $160 for one of ADMs.)

When the time comes, I'll probably still pick up an 8" EdgeHD. The savings when buying it with a mount is actually only a couple hundred bucks, and I already saved some money with the Atlas (it was on sale, and I did not have to buy an ADM dual saddle), so it kind of works out in the end.

Edited by Jon Rista (02/06/14 07:04 PM)


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Chuckwagon
member


Reged: 01/23/08

Loc: Orem, Utah, USA
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6360797 - 02/06/14 10:03 PM

Quote:

Well, all the orders have been made for the interim mount.

Received my Orion Mini Autoguider + SSAG a few days ago.
Ordered an ADM Dual Side-by-side D-style saddle which should be here in a couple days.
Ordered an Astro-Tech Losmandy D-style dovetail plate which has a slit down the middle which will support dual-screw mounting to my 600mm lens, which should be here in a few days.

Finally, ordered a new Orion Atlas EQ-G mount today, which should be here in a couple weeks.

Hopefully this will get me rolling by the end of the month. Thanks for the help with the high end mounts guys. I have a pretty clear idea of what I want to do...just a matter of saving up the dough for it.




Congrats! Enjoy the new toys! Christmas in February, I'm jealous.

Clear Skies,
Charles


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: Chuckwagon]
      #6360849 - 02/06/14 10:29 PM

Quote:

Quote:

Well, all the orders have been made for the interim mount.

Received my Orion Mini Autoguider + SSAG a few days ago.
Ordered an ADM Dual Side-by-side D-style saddle which should be here in a couple days.
Ordered an Astro-Tech Losmandy D-style dovetail plate which has a slit down the middle which will support dual-screw mounting to my 600mm lens, which should be here in a few days.

Finally, ordered a new Orion Atlas EQ-G mount today, which should be here in a couple weeks.

Hopefully this will get me rolling by the end of the month. Thanks for the help with the high end mounts guys. I have a pretty clear idea of what I want to do...just a matter of saving up the dough for it.




Congrats! Enjoy the new toys! Christmas in February, I'm jealous.

Clear Skies,
Charles




Thanks. Half the funds for all this was actually Christmas and Birthday money (Dec. and Oct. last year) that I lumped together and saved, so it's kind of a late christmas and a late birthday for me.

Well, I'll be happy to start doing actual guided exposures, instead of untracked stuff with nothing but my trusty DSLR and a standard tripod. Been trying to image M31 and NGC281 whenever a clear night rolls around, but it just isn't possible without tracking. I get these barely visible 0.8 second exposures at 600mm f/4 w/ 150mm aperture, and even 100 of them stacked aren't enough. At 100mm f/3.5 wide field, even five second exposures still aren't really enough. It's well past time I got some equatorial tracking involved to actually get some real exposures with some actual SNR. Really can't wait.

Seems we get a clear night every five to seven days, so hopefully by the end of the month I'll have a clear night for first light. With all the cloudy days between package delivery and then, I should be well versed in how to use the mount and all the various pieces of software. (Assuming I can deal with the cold...tried to image andromeda again tonight...-9°...my camera got so cold, it was actually painful to touch...and the battery is now extremely sluggish... :\


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orlyandico
Postmaster
*****

Reged: 08/10/09

Loc: Singapore
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6360860 - 02/06/14 10:35 PM

I think the EQ6 is the best mount that $2500 can buy new.

But wait, you say. It's only $1500.

Exactly. I don't see anything less than $3000+ which is a meaningful upgrade. Obviously I don't consider the G11 to be enough of an upgrade. Others may disagree.

The EQ6 can also be upgraded. With better bearings, a better worm - the Aeroquest worm is only $100 or so.

Good interim choice. I suspect that should last a few years... and congratulations for steering away from the CGEM.


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: Buying a telescope...how important is the mount? new [Re: orlyandico]
      #6361231 - 02/07/14 03:03 AM

That, Jon, is a very good choice! I started my AP "career" with an NEQ6 and haven't regretted it. It hasn't done a single night of imaging since I commissioned the GM2000HPS in April of 2010, but I have upgraded it.

Early on I tore it apart and changed all bearings to SKF ones. SKF, as you may know, actually a Swedish company (hear, hear) started in 1907 and world-renowned for their high quality bearings. It took a bite at the wallet but was well worth it. Over Christmas I tore out the first stage gears in favor of a very good belt-drive mod. It is now smooth as a <fill in you favorite word>.

I intent to put it to good use sometime soon as my GM1000HPS will depart out to an island in the Stockholm Archipelago, an island that will house a very small roll-off on a friend's premises. The NEQ6 will go on the balcony pier and I am working on a reliable optical homing sensor so that I dare to at least half-automate it.

Now, do not expect your new mount to be perfect out of the box. Most of them benefit from a worm adjustment, re-grease (use Barium or Lithium grease) and a general tightening adjustment. Astro-baby has all the relevant guides and the process is straightforward and risk-free.

All the best,

Per

Edited by Per Frejvall (02/07/14 03:04 AM)


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6361684 - 02/07/14 11:09 AM

Quote:

Well, I'll be happy to start doing actual guided exposures, instead of untracked stuff with nothing but my trusty DSLR and a standard tripod. Been trying to image M31 and NGC281 whenever a clear night rolls around, but it just isn't possible without tracking. I get these barely visible 0.8 second exposures at 600mm f/4 w/ 150mm aperture, and even 100 of them stacked aren't enough. At 100mm f/3.5 wide field, even five second exposures still aren't really enough. It's well past time I got some equatorial tracking involved to actually get some real exposures with some actual SNR. Really can't wait.





You only have a little over a minute's worth of total integration time, that matters more than the length of the individual subexposures. When you are to the point where it takes thousands of subexposures you definitely need to do tracking or guiding.

Gale


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: Per Frejvall]
      #6361697 - 02/07/14 11:18 AM

Quote:

That, Jon, is a very good choice! I started my AP "career" with an NEQ6 and haven't regretted it. It hasn't done a single night of imaging since I commissioned the GM2000HPS in April of 2010, but I have upgraded it.

Early on I tore it apart and changed all bearings to SKF ones. SKF, as you may know, actually a Swedish company (hear, hear) started in 1907 and world-renowned for their high quality bearings. It took a bite at the wallet but was well worth it. Over Christmas I tore out the first stage gears in favor of a very good belt-drive mod. It is now smooth as a <fill in you favorite word>.

I intent to put it to good use sometime soon as my GM1000HPS will depart out to an island in the Stockholm Archipelago, an island that will house a very small roll-off on a friend's premises. The NEQ6 will go on the balcony pier and I am working on a reliable optical homing sensor so that I dare to at least half-automate it.

Now, do not expect your new mount to be perfect out of the box. Most of them benefit from a worm adjustment, re-grease (use Barium or Lithium grease) and a general tightening adjustment. Astro-baby has all the relevant guides and the process is straightforward and risk-free.

All the best,

Per




Thanks for the tips. I'm really intrigued by the belt drive...I didn't know you could put one of those in one of these mounts, but a belt drive would be ideal. I expected to tune and upgrade the mount at some point...I figure I'll exhaust it's initial accuracy and precision at some point soon enough once I master alignment and start wanting to take longer exposures. Since this is my first computerized GEM, I expect it to feel a lot better than manual GEM's I've used in the past, and having never used a nice $10k+ mount yet, I shouldn't be dissatisfied the moment it's out of the box. ;P


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: gdd]
      #6361709 - 02/07/14 11:23 AM

Quote:

Quote:

Well, I'll be happy to start doing actual guided exposures, instead of untracked stuff with nothing but my trusty DSLR and a standard tripod. Been trying to image M31 and NGC281 whenever a clear night rolls around, but it just isn't possible without tracking. I get these barely visible 0.8 second exposures at 600mm f/4 w/ 150mm aperture, and even 100 of them stacked aren't enough. At 100mm f/3.5 wide field, even five second exposures still aren't really enough. It's well past time I got some equatorial tracking involved to actually get some real exposures with some actual SNR. Really can't wait.





You only have a little over a minute's worth of total integration time, that matters more than the length of the individual subexposures. When you are to the point where it takes thousands of subexposures you definitely need to do tracking or guiding.

Gale




Aye. It also doesn't really seem to matter much if you take 200 or 500 frames and stack them, either. All that really does in the end is reduce noise further, without actually extracting more detail. Actually, I've also noticed that stacking too many frames, when signal is so low, results in a loss of color fidelity...averaging ends up normalizing pixels towards grayish. The signal strength is just too low to really be all that useful. Only way to fix that is increase the time of each sub.


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: Buying a telescope...how important is the mount? new [Re: orlyandico]
      #6361727 - 02/07/14 11:29 AM

Quote:

The EQ6 can also be upgraded. With better bearings, a better worm - the Aeroquest worm is only $100 or so.

Good interim choice. I suspect that should last a few years... and congratulations for steering away from the CGEM.





Good choice of intermim mount because of the open source support available for it. Another thing to keep in mind when using support for mass produced mounts (especially the CGEM) is they will often simply replace the mount rather than fix it if they find problems. If you did some mods, like the Aeroquest worm, you will have it no longer. Better to stick people like Ed at Deep Space Products for support of modded or hypertuned mounts.

I think the G11 is a significant upgrade over the EQ6/EQ-G in terms of choice of materials, precision, and capacity if you can't afford a top end mount. But the G11 is expensive for an interim solution.

Gale


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: orlyandico]
      #6361732 - 02/07/14 11:31 AM

Quote:

I think the EQ6 is the best mount that $2500 can buy new.

But wait, you say. It's only $1500.

Exactly. I don't see anything less than $3000+ which is a meaningful upgrade. Obviously I don't consider the G11 to be enough of an upgrade. Others may disagree.

The EQ6 can also be upgraded. With better bearings, a better worm - the Aeroquest worm is only $100 or so.

Good interim choice. I suspect that should last a few years... and congratulations for steering away from the CGEM.




Yeah, too many people have good things to say about Atlas. Hardly anyone complains about them. Since 2010, a LOT of people have complained about CGEM. Hard to ignore all that.

The mount was only $1400, and since I don't have to buy an ADM Dual Saddle, that saves me another couple hundred. So overall, it really is the best deal on the market right now.

The thing about the G11 is, while it seems it can be tuned and upgraded to get closer to the performance of higher end mounts (<2" P2P PE w/ PEC+guidng), the upgrades are costly. Just the improved worm is $500, and I've read a number of articles about people installing them on their own, and they end up fiddling with it forever trying to get it installed exactly right. If it isn't exactly right, then there can still be a little bit of quirky periodic error. So, you can pay someone to install it, but that only increases the cost even more. After you've paid for all the necessary upgrades and tuning, you've spent as much as an LX850 or CGE Pro, and both of those seem to be able to achieve the same level of performance as a G11 after upgrades with nothing more than PEC, and <2" P2P PE tracking with guiding.

Well, once I get alignment and guiding all figured, and get some upgrades in this thing (probably next year), I'm sure I'll be happy with it while I save for a high end mount. There is also the whole EQMod suite of applications that can be used with it, which includes a mosaic tool and some other handy utilities. I think the EQ6 group of mounts are pretty flexible for their bracket in the market.


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: gdd]
      #6361740 - 02/07/14 11:35 AM

Quote:

Quote:

The EQ6 can also be upgraded. With better bearings, a better worm - the Aeroquest worm is only $100 or so.

Good interim choice. I suspect that should last a few years... and congratulations for steering away from the CGEM.





Good choice of intermim mount because of the open source support available for it. Another thing to keep in mind when using support for mass produced mounts (especially the CGEM) is they will often simply replace the mount rather than fix it if they find problems. If you did some mods, like the Aeroquest worm, you will have it no longer. Better to stick people like Ed at Deep Space Products for support of modded or hypertuned mounts.

I think the G11 is a significant upgrade over the EQ6/EQ-G in terms of choice of materials, precision, and capacity if you can't afford a top end mount. But the G11 is expensive for an interim solution.

Gale




Aye, the open source EQMOD was part of the decision. NexRemote doesn't compare really. I suspect I'll be sending in the mount to Ed when the time comes for hypertuning (unless I decide to get this belt drive...that sounds pretty cool.) I can always get Ed's hypertuning DIY kit as well, I guess, to apply as many of those upgrades as possible along with a belt drive. Anyway, I've been chatting with Ed in PM for a while, and I'll definitely be using some of this services at some point.


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Spacetravelerx
Carpal Tunnel


Reged: 12/23/12

Loc: New Mexico
Re: Buying a telescope...how important is the mount? new [Re: gdd]
      #6361753 - 02/07/14 11:39 AM

Quote:

Quote:

Well, I'll be happy to start doing actual guided exposures, instead of untracked stuff with nothing but my trusty DSLR and a standard tripod. Been trying to image M31 and NGC281 whenever a clear night rolls around, but it just isn't possible without tracking. I get these barely visible 0.8 second exposures at 600mm f/4 w/ 150mm aperture, and even 100 of them stacked aren't enough. At 100mm f/3.5 wide field, even five second exposures still aren't really enough. It's well past time I got some equatorial tracking involved to actually get some real exposures with some actual SNR. Really can't wait.





You only have a little over a minute's worth of total integration time, that matters more than the length of the individual subexposures. When you are to the point where it takes thousands of subexposures you definitely need to do tracking or guiding.

Gale




Yep you need guiding - thousands of subexposures can be painful.

Just for an example, I used ten 120 second subexposures at ISO1600 for M31 with my 80mm APO.

Though, I have to say I have able to go up to 90 sec unguided with my 130mm APO on my little ol' LXD75.

Of course you could also go with encoders, but we have been chatting about that alread...


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: Spacetravelerx]
      #6361878 - 02/07/14 12:41 PM

Quote:

Quote:

Quote:

Well, I'll be happy to start doing actual guided exposures, instead of untracked stuff with nothing but my trusty DSLR and a standard tripod. Been trying to image M31 and NGC281 whenever a clear night rolls around, but it just isn't possible without tracking. I get these barely visible 0.8 second exposures at 600mm f/4 w/ 150mm aperture, and even 100 of them stacked aren't enough. At 100mm f/3.5 wide field, even five second exposures still aren't really enough. It's well past time I got some equatorial tracking involved to actually get some real exposures with some actual SNR. Really can't wait.





You only have a little over a minute's worth of total integration time, that matters more than the length of the individual subexposures. When you are to the point where it takes thousands of subexposures you definitely need to do tracking or guiding.

Gale




Yep you need guiding - thousands of subexposures can be painful.

Just for an example, I used ten 120 second subexposures at ISO1600 for M31 with my 80mm APO.

Though, I have to say I have able to go up to 90 sec unguided with my 130mm APO on my little ol' LXD75.

Of course you could also go with encoders, but we have been chatting about that alread...




I am really curious to see how this 600mm lens with 150mm aperture works for astrophotography. A 150mm aperture on a refractor is pretty big (I mean, if one were to buy an actual high end 150mm APO refracting telescope, like the Officina 152mm, it still costs about twelve grand! Even Orion's 150mm APO is $6500), but when I use it as a visual scope, I can only see andromeda's core, and it's just a faint gray blob. There are a lot more glass elements inside this lens than in the average APO refractor (I guess you have anywhere from two to four elements, my lens has 16). I think part of it is due to the fact that I'm using a DSLR as an eyepiece, the mirror is half-silvered, so I'm probably getting less light than one would with a normal scope and a normal eyepiece. But even when imaging with a 1 second exposure, I get a faint grayish-yellow blob for the core, and that's it. I'm really hoping that once I am tracking and doing longer exposures, my results will change dramatically.

Edited by Jon Rista (02/07/14 12:41 PM)


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6362191 - 02/07/14 03:15 PM

Jon,

The belt kit is really a good start and a cheap upgrade. The mount gets smooth as silk with it. Check out this:

http://rowanastronomy.com/productsa2.htm#neq6beltkit

It takes about an hour to two to install and really works. At that price it is a steal. If he cannot ship overseas, just holler and I'll get it for you and ship it UPS.

A note on stacking. A 10-minute exposure is a 10-minute exposure. Take 50 of them and stack, and it is still a 10-minute exposure because stacking is an averaging process, not an additive one. What happens is that the signal to noise ratio increases, which in turn brings out the details from the noise. You cannot get more light into a picture by stacking 1-minute ones. It is still a 1-minute one but with less noise.

So, you need to guide the NEQ6 from day one. Simple as that.

I may get bashed for this, but please, it is a personal opinion; I'm glad you didn't fall into the Celestron trap

All the best,

Per


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: Buying a telescope...how important is the mount? new [Re: Jon Rista]
      #6362267 - 02/07/14 03:54 PM

Quote:

The thing about the G11 is, while it seems it can be tuned and upgraded to get closer to the performance of higher end mounts (<2" P2P PE w/ PEC+guidng), the upgrades are costly. Just the improved worm is $500, and I've read a number of articles about people installing them on their own, and they end up fiddling with it forever trying to get it installed exactly right. If it isn't exactly right, then there can still be a little bit of quirky periodic error. So, you can pay someone to install it, but that only increases the cost even more. After you've paid for all the necessary upgrades and tuning, you've spent as much as an LX850 or CGE Pro, and both of those seem to be able to achieve the same level of performance as a G11 after upgrades with nothing more than PEC, and <2" P2P PE tracking with guiding.





For $500 you are getting the Ovision 3rd party worm preinstalled in a single piece wormblock. So a lot of the adjusting has already been done. I got the $300 Losmandy One Piece worm block preinstalled when I ordered the mount to avoid the installation problems you are talking about. Actually it is still 2 separate worm blocks but they are held together in a one piece assembly and aligned to the gearbox. There is also a turn screw so worm mesh can be adjusted without tools or having machinist skills.

Most of the stories you hear about are those attempting to align the original 2 worm block system without introducing the 76 sec error that cannot be removed with PEC and is difficult to guide out if severe.

Gale


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Jon Rista
Carpal Tunnel


Reged: 01/10/14

Loc: Colorado
Re: Buying a telescope...how important is the mount? new [Re: Per Frejvall]
      #6362272 - 02/07/14 03:55 PM

Quote:


I may get bashed for this, but please, it is a personal opinion; I'm glad you didn't fall into the Celestron trap





LOL. That seems to be the general sentiment. I will still probably pick up an EdgeHD 8" OTA as my first tube (maybe later this year), unless I wait a little longer and get an Astro-Tech 12" RC next year. People do seem to love their Celestron OTAs, certainly a lot more than they like the mounts.


Quote:


The belt kit is really a good start and a cheap upgrade. The mount gets smooth as silk with it. Check out this:

http://rowanastronomy.com/productsa2.htm#neq6beltkit

It takes about an hour to two to install and really works. At that price it is a steal. If he cannot ship overseas, just holler and I'll get it for you and ship it UPS.





Thanks for the offer! And you are right, it's actually very cost effective. When the time comes, I'll probably get that, and have Ed hypertune the mount.

Quote:


A note on stacking. A 10-minute exposure is a 10-minute exposure. Take 50 of them and stack, and it is still a 10-minute exposure because stacking is an averaging process, not an additive one. What happens is that the signal to noise ratio increases, which in turn brings out the details from the noise. You cannot get more light into a picture by stacking 1-minute ones. It is still a 1-minute one but with less noise.





Oh, indeed, I agree. Reduction in noise, however, does allow you more freedom in pushing the exposure around in a tool like Photoshop. In my first wide field shot with my DSLR and 100mm lens (static tripod, untracked), I was able to extract the ULTRA dim red NGC 434 glow enough that you can barely see the horsehead (it's actually my current avatar picture). So increasing SNR, even when your signal strength itself is still low, can offer some value. It just doesn't get you anything more than amorphous blobs of color most of the time, and overall the images are still relatively noisy. I'm actually attempting to do that now with the Andromeda images from last night...we'll see if I am able to get even the most mediocre image (I know it's kind of pointless to do unguided for such an object, but last night was the first clear night in weeks, and I didn't want to let it go to wast! :P)

Quote:


So, you need to guide the NEQ6 from day one. Simple as that.





Aye. I tested out my Orion SSAG last night. Seems to work with PHD quite fine, so it should be ready to go once the mount comes in.


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Chuckwagon
member


Reged: 01/23/08

Loc: Orem, Utah, USA
Re: Buying a telescope...how important is the mount? new [Re: Per Frejvall]
      #6362283 - 02/07/14 04:01 PM

Quote:

A note on stacking. A 10-minute exposure is a 10-minute exposure. Take 50 of them and stack, and it is still a 10-minute exposure because stacking is an averaging process, not an additive one.




That is generally true, however, you can stack and ADD while stacking. It also adds the noise, so in places where the noise overlaps, it gets worse. As does the sky fog. And you can easily blow out saturated areas very quickly. So adding while stacking may not generally be the best way to do things, but you can do it.

Cheers,
Charles


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: Buying a telescope...how important is the mount? new [Re: Per Frejvall]
      #6362294 - 02/07/14 04:05 PM

Quote:

A note on stacking. A 10-minute exposure is a 10-minute exposure. Take 50 of them and stack, and it is still a 10-minute exposure because stacking is an averaging process, not an additive one. What happens is that the signal to noise ratio increases, which in turn brings out the details from the noise. You cannot get more light into a picture by stacking 1-minute ones. It is still a 1-minute one but with less noise.




But isn't it also true that because the large stack of short images has less noise it can be stretched further in processing before stretching noise becomes unacceptable?

Gale


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