20.43
#...
·
·
8
likes
|
|---|
|
Hello folks. I've been largely absent from the forums for the last couple of months due to my work. Josh from ASG contacted me and asked if I would be interested in testing out a prototype of a motorized version of the Photon Cage. Of course, I'm a complete tilt nerd so you can guess what I said. I'm in the process of putting together a mount/scope in New Mexico and one of my main concerns has been how to address tilt when having techs swap out reducer for flattener. I live 2500 miles away from the hosting facility, so it's not like I can easily visit to take care of this myself. Having worked with a variety of tilt devices and completed hundreds of tilt analysis runs I know just how hard it is to dial in a full frame sensor where microns of adjustment matter. I don't know how well it would go if i had to try and explain fine adjustments to someone remotely. I have a feeling their patience would run out before I was satisfied. My skies have been terrible, but the EAT just arrived so I set it up with my QHY600 on my 110GTX at f5. There is a chance I'll have an opportunity to test this in the next few nights, so fingers are crossed. Last fall I dialed this setup in with the standard photon cage and it took a few nights with adjustments as small as 15um I was able see tilt changes off-axis in the corner. (At the corner of a sensor this is an adjustment of about 5um) This unit has 0.6um resolution which is kind of mind-blowing when you think about it. Trying by feel in the dark with a wrench, I am confident in 15um resolution adjustments... so it will be very interesting to how much simpler it is to dial tilt in without the potential to overshoot an adjustment with a wrench. Here are a few pictures of the prototype. The business end where the adjustments happen is machined, while the rest is 3D printed prototype. It's surprisingly compact. I'll post updates here as I am able.     |
3.58
#...
·
·
1
like
|
|---|
| Wow...I look forward to seeing your results Chris! I just wish I could get a nice clear sky one night here in Alabama. Sending a scope to New Mexico was a great choice and I wish I had done it sooner! |
|
20.43
#...
·
·
2
likes
|
|---|
Daniel Carter: I had a couple of nights to play around with it, and so far so good! I was running ASTAP and making adjustments from inside my living room... mind you it was 20 degrees F outside, so really nice to not need to go out every 10 minutes to make an adjustment. I'm really looking forward to more testing, but I was having some optical issues that I need to sort out. So far it;s been a pleasure to play with! |
0.00
#...
·
·
2
likes
|
|---|
| I’ve been dreaming about something like this. Should be relatively straightforward for developer to integrate with Aberation Inspector to automate tilt and backfocus adjustment. The hard work is done. Just need to calibrate device, send adjustments / instructions and iterate. Now just need someone to do the same for secondary mirrors and Innovations Foresight to integrate that with SkyWave. |
|
20.43
#...
·
·
3
likes
|
|---|
Tom Dinneen: I suspect that this is the future for devices like this once they hit the market. I would ABSOLUTELY love this to be an automated process. I don't know what the projected retail price is on this EAT device, no doubt it will not be cheap, but if it could eventually be automated it would add significant value to that price tag. I, for one, would much rather image than tinker with tilt.... |
2.10
#...
·
|
|---|
| I guess I should feel very lucky to be able to image from my driveway. |
|
0.00
#...
·
·
1
like
|
|---|
Chris White- Overcast Observatory:Tom Dinneen: Even better would be a kit to upgrade existing Photon Cages with motors. Might not be achievable but one can dream. I suspect in 2-3 years or less given the rate of progress the last 2-3 years that tilt adjustment will be an automated process. Ditto mass production scopes coming with motorised / automated collimation within the next 5 (likely 2-3 years as well). Only a matter of when not if. I’m all for imaging as well. Adjusting tilt and collimation is fun up to a point and I’m well past that point. Tom |
2.41
#...
·
·
5
likes
|
|---|
|
To add to the beta testing discussion here, I have the other one mounted to my RASA 11... and its been working good as well. I think there is a place here for these for sure in remote observatories, or even home observatories permanently mounted IF a person was wanting to remotely work on these things. It certainly has been doing well for me being able to adjust backfocus and also tilt for an hour all without touching things. At this type of final resolution we are working with, feels like a lot of error can come from just simply touching things. I think there will always be a place for a simple mechanical device like the regular photon cage. Sort of like having a mechanical tripod for a mount or a fancy self-leveling, polar aligning, motorized tripod you can drive out of your garage... they both work good, do the job equally as well, most are good with the stock tripods, but who wouldn't dig a self-leveling, polar aligning, motorized tripod  lolone comment on automated tilting, the computer right now takes serial commands in a way that could easily be integrated with automated focus runs... It really will be something we see happen eventually, whether with this or not, but just as standard as Electronically Assisted Focus is. It is just going to be part of the setup process, like polar aligning & focusing, a camera alignment procedure to get better images in the end.  |
1.20
#...
·
|
|---|
|
Oh wow, this device seems super interesting! Would love to up-level my manual photon cage with this one at some point! Ani |
12.64
#...
·
|
|---|
| This device is working great on one of my scopes, but I had to go up and down on a ladder to adjust it since my scopes are 10 feet above the observatory floor. This would eliminate that problem and probably arrive at a more accurate result than doing it manually. |
3.31
#...
·
·
1
like
|
|---|
| Await the outcome, I'd kill for someone to finally produce a tilt mechanism that doesn't involve screwdrivers or fingers. |
|
2.41
#...
·
|
|---|
| I will say that this is not anything like the mechanical ones. It in no way will 'upgrade' or just 'add motors' to it, it's a completely different beast, but we are making it so it's compatible with all our ASG filter sliders. It also has M54 threaded aperture, common 6 bolt EFW pattern on 62mm diameter... I also added 4 of the 6 x 99mm bolt pattern if you wanted to bolt it to the ZWO 50x50 filter wheel. I think that is a pretty good deal on that size EFW. So compatibility wise it has a ton of mountable features... |
|
20.43
#...
·
|
|---|
Josh Jones: Thanks for chiming in Josh. It looks like I have some more testing opportunities over the next few nights. I currently have it setup on the 110 with the field flattener. The reducer needed to go back for service. I may have a chance to set this up on my epsilon. I reached out to OPTEC to see where they were with the Hercules (small format focuser/rotator) as my epsilon is in pieces right now and when I set it back up I'd like to upgrade to it. If it is a ways out, I'll set it back up with the LEO, and get some superfast scope testing done with the EAT. Being winter in Vermont, I dont generally like testing things.... but in this case, I can do it all from my warm living room. :-) |
3.61
#...
·
|
|---|
| Very interesting device. I own a Photon Cage and found it easy to use. I am very interested in how this works on an Epsilon! |
|
20.43
#...
·
·
3
likes
|
|---|
|
I'm using it right now. Currently 20C in my living room and -10C outside. One thing that is important to note is that unlike a manual tilt device, when you make an adjustment with the EAT you do not impact your backspacing at all. If you increase spacing on a specific corner, the opposite corner does an inverse movement. Mechanically, it has to, but the practical benefit is that your backspacing is unchanged. So you can make all the corner adjustments you want, and spacing stays the same. With a manual (4 point) device, this is also the case if you loosen the opposite corner, however I was never confident that I could perfectly achieve this. Essentially, you are pivoting the device on the locked corners, but it is balance between being too tight and not tight enough. With a manual (3 point) device, you are definitely impacting your backspacing. For very fast scopes, this can be an issue. With my epsilon 0.1mm makes a difference! |
|
20.43
#...
·
·
1
like
|
|---|
|
Here is a result with my 110GTX and field flattener and QHY 600. To achieve this result I adjusted the corners relatively by the following amounts: Top Left: 0 (reference corner) Top Right: -14 steps (-8um) Bottom Left: 224 steps (134um) Bottom Right: 210 steps (126um) I was making adjustments as small as 5 steps. After I dialed in tilt I started tweaking the backspacing at 25 steps per movement, or 0.05mm. This is a super cool gadget! I plan to setup my epsilon in the near future and give this thing a torture test.... Here is a high res sub. No editing: EDIT: Link to come, ABIN is having server errors when uploading... |
|
20.43
#...
·
·
1
like
|
|---|
|
Last night I had a chance to test the EAT motorized tilt device on Epsi. My sky conditions were not very good with seeing around 2.8" and poor transparency. Under better conditions star aberrations are more pronounced so may require more refinement... I would call my collimation an 8/10 so that can be improved as well. I was rushing over the last couple of days to install the focuser and change mirror spacing, so it's a quick and dirty on the collimation. I previously tested EAT on a refractor. Moving it to the epsi I thought it was going to be a bit of a torture test, but I was wrong. The device handled it easily and adjustments produced expected results and were repeatable. I ran ASTAP Hyperbolic Curve Analysis 9 times over the course of 75 minutes. 7 of those runs resulted in tilt adjustments and 2 of them with backspacing adjustments. I ended up maxing out the travel of the EAT as I was refining backspacing so I need to put a 1mm shim in my image train to continue refining spacing, but this result is quite good after only 75 minutes of tinkering. I'll add that I did all of my tinkering while reclined on my couch in my living room sipping a beverage with my feet up on the coffee table. Here is the Before Image without any tilt or spacing refinement. As you can see there is clearly a spacing and tilt issue. High res file here for pixel peepers: https://www.astrobin.com/1yyvfq/0/  Here is the After Image after making 9 adjustments following the guidance of ASTAP Hyperbolic Curve Analysis: https://www.astrobin.com/1yyvfq/B/  There is still some residual error to refine but visually the result is very good, especially considering this is a full frame chip on an ultra-fast telescope. I'll be adding a shim and taking this to the next level once I get another clear night. I did a bit of spacing testing of the device itself. Once I refined tilt I ran the device in and out across about 1mm of travel range. It held my tilt adjustments perfectly. I am extremely impressed with this device. In the past I would not continue refining this result. I'd be happy with it and leave it alone. Now, I'm excited to see just what this system is capable of delivering for star quality! One more step on the path to remote deployment! |
|
20.43
#...
·
·
2
likes
|
|---|
|
I had a second night to tinker with the EAT device on epsi. My seeing is not that good here, with this sub measuring at 3.3". In better seeing the diffraction artifacts will be more pronounced, and any remnant tilt or spacing error will be more visible (and require an adjustment). This is just about the best field I have been able to achieve with Epsilon. When I first dialed this in with Octopi and Photon Cage a couple years ago it took many nights of adjustments to get anywhere near this. I was able to do this on night 2 with the EAT, and only spend about 3 hours tinkering and testing and running analysis. Pretty awesome for a full frame sensor on an f3.3 astrograph! High res for you pixel peepers... https://www.astrobin.com/1yyvfq/D/  |
|
20.43
#...
·
·
2
likes
|
|---|
Here is a slightly better sub: https://www.astrobin.com/1yyvfq/E/ |
