Great info, yes keep it up since you have the equipment. You are the only source of this type of testing for astrophotographers, it is worth a million dollars to me!!!
That’s a nice scope. A superbly explained video. You see, not e everyone has a “backlash testing machine”, which it is so unusual to see this explained anywhere else. Atta Boy. Keep up the good work!
Thanks for posting this, great content! One test that I did (with a dial indicator) was to get the full backlash through the EAF. I put the dial indicator on the fine focusing wheel and moved the EAF back and forth in increasing steps until I got movement on the dial.
Impressive testing. You and 'Dark Sky Geek' are doing in-depth research. Maybe his last collimation testing video was really off because he didn't factor in draw tube weight flex you just tested.
I think this a great test for astrographs and if more reviewers started doing this kind of test manufacturers might start giving more attention to this aspect of performance.
I have to ask because you're looking better around your eyes. HOW ARE YOU FEELING? We send prayers up for you quite often. It's great to see you looking better. SO...HOW ARE YOU?
Didn't realize this was different than a Crawford focuser. The test makes having bought this OTA even more satisfying, knowing it's a quality design. I had my first imaging session last night. Impressed for the first time using such a long focal length.
Great video! I've never seen this type of tests done on a focuser. A comparison with another popular type of focuser (like the one on SVBONY SV503 102mm for example ) would be very interesting. Keep up the good work!
Yes. Please do more like this. I 3D printed a tube support for my SV48p focuser tube because the droop was extremely noticeable. We're talking 32nd maybe even 16th. I still have some fine tuning on it the height (ie just sand off a little from the bottom) but its made a huge difference in eliminating the roatating sag.
Very interesting tests...I would definitely like to see more! I need someone like you as a neighbor. I"d LOVE to have access to a lathe & a mill. If not access myself, it would be awesome to have a neighbor with a shop who's willing to do small side projects from time to time!
Measure the deflection when moving the focuser in and out! How many axis could you measure simultaneously? Backlash is just a part of the equation, but to see how much an assembly might deviate when the direction of travel is changed would be interesting too! I really want to add that Askar 120 to my collection. It's good to see you show what kind of quality your getting for the money! Thanks so much!
I think this sort of testing could potentially be quite interesting if at some point in the course of your investigations, you could determine how much sag corresponds to visible tilt in the image with a reasonably large sensor. From that point onward we would have an idea of whats good, acceptable, and poor. Keep at it!
This is very interesting. When I installed the ZWO EAF on my Stellamira 80ED (that is in the "not supported" list), I had to remove the focuser tensioner/stop. I could see that the backlash changed according to the focuser tensioner (not surprising). As the bracket needed a "custom" mount of the bolts, this made me be very precise when mounting the bolt in the same threaded hole as where the focuser tensioner grub screw was. (no other place to install the bracket bolt unless drilling/threading in the tube which i did not want to do).
Very interesting, would love to see this test on the Esprit range of scopes, as there focusers seem very solid…but a test on them would prove or disprove this theory…👍🏻
Very useful, amigo, as Celestron tech support just told me to install a Crayford focuser if I want to reduce / eliminate mirror flop in my C6 SCT. So your video was highly valuable to me. Thank you. Plus ... we're all Geeks!
Good info. With a little math, wavelength of light..., and knowing the distance to the flexure point, we can determine how much flex it takes to degrade an image.
Not too bad in Excel. I'd math out the distance to outside edge of each side of the sensor, based on the angle of deflection.. There is an equation for the narrowness of focus based on f ratio etc. if the flex exceeded that,... without having to wait for a clear night, the performance can be objectively calculated. So yeah.. a little bit of math ;) Haha.
Excellent content, thank you. Really looking forward to your full review of the Askar120 APO. I do have one quick question. Did I notice that you had reinstalled the focus lock screw after you installed the EAF? I just installed an EAF on my 120 and didn’t reinstall the focus lock screw because I assumed that the resistance of the EAF motor would eliminate any pull when the scope is pointed up. After watching your test results it would seem that between the motor’s resistance and how solid the rack and pinion gears are the locking screw isn’t needed. Am I missing something ? Again great video, keep it up.
Hello , I just wanted to ask how you are doing. I don't comment much but i did want to see how you were making out. Thank you for all the help as I'm new to astrophotography but I've been viewing through telescopes for about 3 decades.
Hi Ben you're looking well? Definitely some interesting testing it would be good to see it compare to the SV Bony scopes you have, Crayford focusers on Skywatcher telescopes I find to be pretty poor & I much prefer the rack & pinions like on the Askar or my Altair 102 EDR
i found it great so to me it sounds like the focuser on this NEW askar telescope decent i only do visual with some smart phone imaging BUT iam thinking of getting the askar 140 near the end of the year if i first sell my Takahashi 150B TOA refractor. Iam asking them if they can send me the 140 to test and also review but your review is nice as it tell me the focuser is decent & wont need to be replaced with something saving money.
A very interesting series of tests. What i would like to know if you started an exposure of a few minutes duration would the image train flex during the tracking or does it flex once when the load is first applied and stay in that flexed state with no further movement? Also with the movement you saw if, for example, you started a 1 minute exposure with no flex and ended the exposue with a few thou of movement how much movement across the image sensor is that, less than a pixel, a few pixels, tens of pixels ( obviously dependant on pixel size)?
Really I would just try to get it straight. Correcting for tilt though is what you are doing. Finding the measured correlation with tilt though might be more work then it is worth.
If this movement actually shows up in images maybe astrophotographers need to be building cages around their setups and locking each component of the imaging train in place.
Your missing vital information. I work with machinists and know the metric system well. So, with the .004 of flexure, what did that actually do to the image? Can you please take one with and without it. No autofocusing on the second image.
This has to be one of the most involved and brilliant focuser reviews I've ever seen... Astoundingly informative video!
Great info, yes keep it up since you have the equipment. You are the only source of this type of testing for astrophotographers, it is worth a million dollars to me!!!
That’s a nice scope. A superbly explained video. You see, not e everyone has a “backlash testing machine”, which it is so unusual to see this explained anywhere else.
Atta Boy.
Keep up the good work!
Yay, great video! Yes, please do more testing like this on other focusers and non-screwed connections (clamp or ring) bearings. 🎉
Very cool! It'd be interesting to compare some of the common focusers.
Good to see you in good spirits and in good shape!! Congrats.
Thank you!
More technical videos please! I really enjoy your channel!
Thanks for posting this, great content! One test that I did (with a dial indicator) was to get the full backlash through the EAF. I put the dial indicator on the fine focusing wheel and moved the EAF back and forth in increasing steps until I got movement on the dial.
Very informative video and would love more! This APO really knocks it out of the park for value.
Impressive testing. You and 'Dark Sky Geek' are doing in-depth research. Maybe his last collimation testing video was really off because he didn't factor in draw tube weight flex you just tested.
Thanks for this great video. Really a very interesting test. I would love to see more like these. Be well!
Great technical validation of performance. Definitely do more of these types of content.
Really enjoyed this test. Please continue down the path.
very interesting. if you continue to do these tests when you can we (viewers) can get a feel for baseline that is not just subjective. thanks.
Nice to seeing you again. I was missing you😊 Grear video😊
Interesting. You're doing things I haven't seen elsewhere and I think it's of use.
Ah great to see this, from an Engineers perspective. Excellent.
Glad you enjoyed it!
I think this a great test for astrographs and if more reviewers started doing this kind of test manufacturers might start giving more attention to this aspect of performance.
I have to ask because you're looking better around your eyes. HOW ARE YOU FEELING? We send prayers up for you quite often. It's great to see you looking better. SO...HOW ARE YOU?
Yes, thank you i am getting a little better. Still have a long fight ahead though.
Didn't realize this was different than a Crawford focuser. The test makes having bought this OTA even more satisfying, knowing it's a quality design. I had my first imaging session last night. Impressed for the first time using such a long focal length.
Great video! I've never seen this type of tests done on a focuser. A comparison with another popular type of focuser (like the one on SVBONY SV503 102mm for example ) would be very interesting. Keep up the good work!
I will be doing one soon.
Yes. Please do more like this.
I 3D printed a tube support for my SV48p focuser tube because the droop was extremely noticeable. We're talking 32nd maybe even 16th. I still have some fine tuning on it the height (ie just sand off a little from the bottom) but its made a huge difference in eliminating the roatating sag.
Amazing video. Yes, would like to see more like this .
One of the best if not the best astrophotography channels on UA-cam!!
Very interesting tests...I would definitely like to see more! I need someone like you as a neighbor. I"d LOVE to have access to a lathe & a mill. If not access myself, it would be awesome to have a neighbor with a shop who's willing to do small side projects from time to time!
Measure the deflection when moving the focuser in and out! How many axis could you measure simultaneously? Backlash is just a part of the equation, but to see how much an assembly might deviate when the direction of travel is changed would be interesting too!
I really want to add that Askar 120 to my collection. It's good to see you show what kind of quality your getting for the money!
Thanks so much!
I think this sort of testing could potentially be quite interesting if at some point in the course of your investigations, you could determine how much sag corresponds to visible tilt in the image with a reasonably large sensor. From that point onward we would have an idea of whats good, acceptable, and poor. Keep at it!
Great idea, and, in a machine shop setting. More metrication? Yes please.
Coming soon!
This is very interesting. When I installed the ZWO EAF on my Stellamira 80ED (that is in the "not supported" list), I had to remove the focuser tensioner/stop. I could see that the backlash changed according to the focuser tensioner (not surprising). As the bracket needed a "custom" mount of the bolts, this made me be very precise when mounting the bolt in the same threaded hole as where the focuser tensioner grub screw was. (no other place to install the bracket bolt unless drilling/threading in the tube which i did not want to do).
They need to fix that. The EAF is as universal as water these days.
Very interesting, would love to see this test on the Esprit range of scopes, as there focusers seem very solid…but a test on them would prove or disprove this theory…👍🏻
Very useful, amigo, as Celestron tech support just told me to install a Crayford focuser if I want to reduce / eliminate mirror flop in my C6 SCT. So your video was highly valuable to me. Thank you. Plus ... we're all Geeks!
Glad it helped
This is really interesting Ben👍
Glad you think so!
Good info. With a little math, wavelength of light..., and knowing the distance to the flexure point, we can determine how much flex it takes to degrade an image.
Just a little bit of math :)
Not too bad in Excel.
I'd math out the distance to outside edge of each side of the sensor, based on the angle of deflection..
There is an equation for the narrowness of focus based on f ratio etc. if the flex exceeded that,... without having to wait for a clear night, the performance can be objectively calculated.
So yeah.. a little bit of math ;)
Haha.
Yes, I'm being a bit sarcastic :p
Holy cow bud, that's some testing! Well done!
Such a fantastic video, Ben! Really enjoyed it
Glad you enjoyed it!
Excellent content, thank you. Really looking forward to your full review of the Askar120 APO. I do have one quick question. Did I notice that you had reinstalled the focus lock screw after you installed the EAF? I just installed an EAF on my 120 and didn’t reinstall the focus lock screw because I assumed that the resistance of the EAF motor would eliminate any pull when the scope is pointed up. After watching your test results it would seem that between the motor’s resistance and how solid the rack and pinion gears are the locking screw isn’t needed. Am I missing something ? Again great video, keep it up.
I put it back so it does not get lost.
Hello , I just wanted to ask how you are doing. I don't comment much but i did want to see how you were making out. Thank you for all the help as I'm new to astrophotography but I've been viewing through telescopes for about 3 decades.
Hi Ben you're looking well? Definitely some interesting testing it would be good to see it compare to the SV Bony scopes you have, Crayford focusers on Skywatcher telescopes I find to be pretty poor & I much prefer the rack & pinions like on the Askar or my Altair 102 EDR
i found it great so to me it sounds like the focuser on this NEW askar telescope decent i only do visual with some smart phone imaging BUT iam thinking of getting the askar 140 near the end of the year if i first sell my Takahashi 150B TOA refractor. Iam asking them if they can send me the 140 to test and also review but your review is nice as it tell me the focuser is decent & wont need to be replaced with something saving money.
A very interesting series of tests. What i would like to know if you started an exposure of a few minutes duration would the image train flex during the tracking or does it flex once when the load is first applied and stay in that flexed state with no further movement? Also with the movement you saw if, for example, you started a 1 minute exposure with no flex and ended the exposue with a few thou of movement how much movement across the image sensor is that, less than a pixel, a few pixels, tens of pixels ( obviously dependant on pixel size)?
Great work mate👊
Pretty cool dude! You going to Neaf this year??
Yes i will be there
Very interesting! Could you measure and correct tilt with this ?
Really I would just try to get it straight. Correcting for tilt though is what you are doing. Finding the measured correlation with tilt though might be more work then it is worth.
Nice gizmo.
Hi, this is interesting, can you do the same thing with the smaller 2.5 focuser on the sv550 122?
Thank you for the reminder. Now that its back i can and will have to soon n
If this movement actually shows up in images maybe astrophotographers need to be building cages around their setups and locking each component of the imaging train in place.
Your missing vital information. I work with machinists and know the metric system well.
So, with the .004 of flexure, what did that actually do to the image?
Can you please take one with and without it. No autofocusing on the second image.
I would have to image sine how with force exhibited on the focuser. Would probably have to make some sort of jig or something.
Ok, now if it's a helical gear less movement?
Helical will have more the the other type mentioned.
Like
Shit yes. Do more.