Celestron 6SE vs 8SE with CMOS digital astronomy?

[Knighty2112]

1 hour ago, theskyisthelimit99 said:

Wanted to follow up on this.

Curious what model dovetail you bought and did it come with screws that just connect the two together somehow?

By balance did you mean to keep it from wanting to move in elevation through bumping it etc?

Last nite i had about 3" to the right of the mount (if you go by your picture about 3" of dovetail bar extending to the right).. i targeted a nebula, must have been near zenith, my cmos + barlow hit into the mount area when it aimed up, so actually i think i need it further back, almost with the mount more centered.. the issue with centering i found, was that as it moved in elevation it was slipping due to being top heavy from the centering (i think it was mentioned there is a way to adjust the tension, manually, unsure, might be the ultimate fix)..

So i'm not sure if this added dovetail would help with keeping the mount further towards the middle of the scope or not.

I cant seem to find too many 8se pics showing the ideal position in relation to the mount to tell.

 

I also cant get perfect 2 star alignment, always off by maybe 1/2" in the 9x50 scope when i target a planet, not a big bother, but maybe this is the norm?

 

 Not sure what brand dovetail it was, just one I’d acquired second hand I think that had slots part the way down it so you could line screw holes up relatively easily. The screws never came with it, again used some I acquired over the last few years. I’ll take some photos tomorrow evening of the bar and give you some measurements if you want to try to locate a similar one. 

Balancing means yes to stop it been back heavy when you larger eyepiece, heavy diagonals, cameras etc to the back that makes the scope go downwards so messes around with the goto tracking etc. I’ll give you a few tips to try and get a better alignment tomorrow as well.  

[Knighty2112]

BTW: sounds like you put the bar central to the dovetail, which will put too much weight to the back of the scope. You need to slide the scope forward in the dovetail almost as far as it will allow you to go without the scope back area getting in the way of locking the dovetail in correctly. You should get a better balance of the scope like that.

[theskyisthelimit99]

17 hours ago, Knighty2112 said:

BTW: sounds like you put the bar central to the dovetail, which will put too much weight to the back of the scope. You need to slide the scope forward in the dovetail almost as far as it will allow you to go without the scope back area getting in the way of locking the dovetail in correctly. You should get a better balance of the scope like that.

In one test i had the dovetail/tube centered on the mount, which proved unbalanced as you say.  The last one I slid it all the way back to where you only see about 1-2" of dovetail, but i think when i had a barlow + adc + cmost attached and targeted something high near zenith, i think it basically bumped into the flat part of the mount when it angled up.. I feel like rather than only 1 or 2" clear on the rear it needs more like 3ish, or maybe that was a rare situation with things attached.. i didnt really need the adc on there but after doing mars i targeted something high without taking off the adc, i guess without it it would have been fine.

DId you get that avx mount yet.. i'm curious if its much better and since its an eq and all.  I've read people say it does well, despite the few that say you need to go with more expensive solutions.

Since I switched to the 9x50 celestron illuminated finderscope too, i've been pretty happy.. i can now get it re-aligned (the finderscope) in about 5 minutes (seems to need realigned even if not removed) and ready for action in 10, better than the 45 minutes to hour i seemed to struggle with before.  I've left the red dot on the left for now, the 9x50 on the right.  The red dot just helps me get in the neighborhood of the object and the 9x50 to fine tune it (especially for cmos)

EDIT: i also now have a astrozap dew heater and i have one of those celestron pro lithium batteries coming (opted to pay a little more for this one and get rid of the two lithium packs i have).. i'm debating where to attach the dew heater controller (velcro).. either just below the controller pad or maybe on the flat of the mount.. i'm not sure if either will affect tracking.. i've seen people do both?

 

[Knighty2112]

3 hours ago, theskyisthelimit99 said:

In one test i had the dovetail/tube centered on the mount, which proved unbalanced as you say.  The last one I slid it all the way back to where you only see about 1-2" of dovetail, but i think when i had a barlow + adc + cmost attached and targeted something high near zenith, i think it basically bumped into the flat part of the mount when it angled up.. I feel like rather than only 1 or 2" clear on the rear it needs more like 3ish, or maybe that was a rare situation with things attached.. i didnt really need the adc on there but after doing mars i targeted something high without taking off the adc, i guess without it it would have been fine.

DId you get that avx mount yet.. i'm curious if its much better and since its an eq and all.  I've read people say it does well, despite the few that say you need to go with more expensive solutions.

Since I switched to the 9x50 celestron illuminated finderscope too, i've been pretty happy.. i can now get it re-aligned (the finderscope) in about 5 minutes (seems to need realigned even if not removed) and ready for action in 10, better than the 45 minutes to hour i seemed to struggle with before.  I've left the red dot on the left for now, the 9x50 on the right.  The red dot just helps me get in the neighborhood of the object and the 9x50 to fine tune it (especially for cmos)

EDIT: i also now have a astrozap dew heater and i have one of those celestron pro lithium batteries coming (opted to pay a little more for this one and get rid of the two lithium packs i have).. i'm debating where to attach the dew heater controller (velcro).. either just below the controller pad or maybe on the flat of the mount.. i'm not sure if either will affect tracking.. i've seen people do both?

 

You need to set a slew limit on the mount to stop the diagonal and EP hitting the base when getting anywhere near zenith. Think I had mine set at around max limit of 75 degrees, but depending on what your putting into the optical chain on the scope you will need to set your max limit to suit your set up. You may end up with a limit lower than this though.

The AVX so far is doing very well. I’m using Starsense with the AVX mount and C8 scope too, which so far makes it super accurate and easy to set up alignment. Only down side (and this is true off all EQ mounts) is that it moves the EP around quite a lot at different angles. But apart from that liking the AVX, although it does take longer to set up than the SE mount, which I could carry the mount and scope outside in one go and get it up and working in about 5 mins max, whereas there are about 4 journeys carrying stuff out from the house with the AVX to get it set up, so that takes at least 15 mins at best to get it up and ready to do an alignment. As Starsence also works on the SE mount too I may try it on that mount also and see if there is an improvement in accuracy on the mount.

Here are a few pictures below of the dovetail I used on my C8 on the SE mount and the holes I utilised on the original dovetail to piggy back them both together with a couple of screws/bolts. This is a pretty generic 7”  dovetail bar which can be got in the UK at least from FLO. You should be able to source a similar if not identical one over on your side of the pond quite easily I believe.  BTW: I showed a ruler with both imperial measurement in inches, and also in milli/centimetres too if needed.  

https://www.firstlightoptics.com/dovetails-saddles-clamps/adm-vixen-style-universal-dovetail-bars.html

 

 

[Knighty2112]

Here’s some images showing what you can achieve with the extra dovetail fitted onto the system with various combinations of items in the imaging chain;

First one with a Vixen flip mirror fitted with EP (camera not shown fitted to the lower part) which only allows approx a 70 degree angle before it would then hit the base of the mount;

 

Next few images showing with just a 2” diagonal screwed directly on to the back of the SCT with an EP fitted which with the extra dovetail fitted allows me to have the full 90 degree movement all the way up to Zenith;

 

[impactcrater]

I like your 'let's try this' approach . it is very refreshing. when my corrector gets too dewy i just give up and take everything inside and leave the caps off and in the morning everything looks fine. telescopes are pretty tough. a little bit of lint on the corrector does not affect viewing and whilst initially I used a microfiber cloth i suspect this is a 'no-no'. certainly don't rub it round and round. I'm sure 'windex' is a definite 'no-no' as it will smear and may damage the protective film over the corrector lens.

Please note i picked up what I think I know on this site and I am no optics expert.

[theskyisthelimit99]

On 25/07/2018 at 14:37, Knighty2112 said:

You need to set a slew limit on the mount to stop the diagonal and EP hitting the base when getting anywhere near zenith. Think I had mine set at around max limit of 75 degrees, but depending on what your putting into the optical chain on the scope you will need to set your max limit to suit your set up. You may end up with a limit lower than this though.

The AVX so far is doing very well. I’m using Starsense with the AVX mount and C8 scope too, which so far makes it super accurate and easy to set up alignment. Only down side (and this is true off all EQ mounts) is that it moves the EP around quite a lot at different angles. But apart from that liking the AVX, although it does take longer to set up than the SE mount, which I could carry the mount and scope outside in one go and get it up and working in about 5 mins max, whereas there are about 4 journeys carrying stuff out from the house with the AVX to get it set up, so that takes at least 15 mins at best to get it up and ready to do an alignment. As Starsence also works on the SE mount too I may try it on that mount also and see if there is an improvement in accuracy on the mount.

Here are a few pictures below of the dovetail I used on my C8 on the SE mount and the holes I utilised on the original dovetail to piggy back them both together with a couple of screws/bolts. This is a pretty generic 7”  dovetail bar which can be got in the UK at least from FLO. You should be able to source a similar if not identical one over on your side of the pond quite easily I believe.  BTW: I showed a ruler with both imperial measurement in inches, and also in milli/centimetres too if needed.  

https://www.firstlightoptics.com/dovetails-saddles-clamps/adm-vixen-style-universal-dovetail-bars.html

 

 

I'm a little slow to get to this

Now that i've been doing some DSLR, i'm hoping this trick will help allow the scope to sit more forward / up so that the f6.3 reducer + tring and ring adapter + canon 6D fit without hitting the base..

I havent had a ton of luck in looking for this exact dovetail via usa stores..

however.. i'm wondering if something like this ($50).. might work (8.9") https://www.amazon.com/Astromania-DeLuxe-Dovetail-Plate-length/dp/B01LZ377Z1/ref=sr_1_fkmr1_3?ie=UTF8&qid=1547063305&sr=8-3-fkmr1&keywords=7"+Dovetail+bar 

Other cheaper solutions i've seen seem to have less holes as options.

How did you figure out what type of screws to use to put the two together though?

 

EDIT: appears this might actually be the same 7" one you have at hs: https://www.highpointscientific.com/brands/adm-accessories/adm-accessories-vixen-style-universal-dovetail-plate-7-long-vdup7 $50 as well