johneta

Good question, I have forgotten 😔. I think that info is on the Toms AstroEQ website. I think you basically have to know the worm gear ratio of your mount (search for model online usually works), and then do some calculations and guesses on how many motor revolutions it takes to spin the mount 1 revolution. Im pretty sure I multiplied all that out and got a rough idea of the number of teeth on the pully I needed. But its not to critical as once you decide on the pully teeth number, and buy them, then you can input those actual numbers into Toms AstroEQ configuration software and it calculates the pulse rate to the motors to get the right speed.

Hi, if I'm understanding you correctly, I haven't done exactly as you mention, but I have tried various transform tools and others in PS, and I can get it to look OKish but never quite right. As I allude to above, I think I have figured that I just haven't got enough images at a high angle. This is to do with how the camera sweeps on a standard 3way camera tripod head. when aiming up at a high angle (around 50degs). I basically need a couple more shots of width up there for there to be enough information to match the bottom of the image which is swept at basically a horizontal angle (0degs). When I study the stitched pano along the top row particularly, I can see the stars are getting stretched as the software tries to add width to the top of the image. Ive decided to mount the pano rotating bit on the camera plate of the tripod so that the pano sweep goes in big arcs as the head is tilted upwards for the top rows. That's the theory, and I will post how I go. have a look at this if your interested in the Panorama Milkyway concept. Some handy tips. https://www.lonelyspeck.com/how-to-shoot-large-format-astrophotography-panoramas/comment-page-5/#comment-321114 The main difference with his image and mine I think is that he hasnt gone very high in upwards angle (Alt) and therefore not as much narrowing at the top as I'm getting

Yes I'm lucky light pollution is low, as seen from the milkyway image above . Thats basically out my back door

Ok thanks. Nice, that one done with your SW200P in your gear list? I use an Orion 8" F3.9 and find the Rosette just fits awkwardly in the frame but I would like a bit more space around it like you have there. Its a bit hard to get down here in NZ - lowish in the sky in summer when my sky's are cloudy for months

Thanks almcl. I'll have a look at some of those articles. I've got an old copy of ICE on an old laptop. I'll try it again. I remember thinking it wasn't that good, but that was a few years ago, so I'll have another look at it with fresh eyes. Thanks for having a go at straightening, it looks good. I also thought a bit more about taking the images, and realized as you point close to vertically up with the camera and pivot on the pano base, then you are really just pivoting round that point and get a small circle of view straight up. Whereas when cam is horizontal it does a big sweep left and right as it pivots on the pano base. Therefore you are recording less "width" at the top of the image. Thus its tapered at the top of a 'square' image. I might experiment with a small angled wedge under the pano rotating bit. This means I would have to effectively point the camera 'down' by a small angle relative to the pano base in order to get the horizontal land images. And then the overhead images would be at less up angle relative to the pano base, and therefore have more 'sweep' on the top row of images and therefore will capture more width, which will make the overall image closer to square. I'll post how I go with this

Hi I'm hoping someone can give me advice on milkyway multi image panos. I'm trying to do a few multi image panos for high resolution. Most panos I try always end up being narrower at the top- As shown in the image. I used Hugin in this image and i tried all the different projections and drag it around to try and straighten the image. When it does start to straighten, then the milkyway at the top of the image, gets very stretched and too wide. While the bottom part of it looks the right width. To try and get the milkyway the correct width at the top, I always end up with a tapered image as show. I can mess around in photoshop to warp it etc. but I would like to understand why it is happening. This image is about 6 images wide x 6 images high. (around 36 total) All shot with a 6d in landscape orientation with a 58mm lens. Camera was about horizontal on bottom row and pointing up by about 50 degrees on last row

Sounds good chemistorge. There are many ways to do it for sure. Interesting about your controller being quiet. My motors aren't quiet but it doesn't bother me.

Hi Astrosathya, Sorry I only saw your post today. Do you still want any info. Over the past 2 years it has operated well. I still get good guidance and generally no problems. I looked at the Arduino Mega option too as I make a few things myself with Arduino. But it just didnt seem worth it. Tom's board works right off the bat. You do have to be a little confident with electronics and soldering, but it is pretty straight forward. The new setup just means my system is very reliable and I dont have to think about the Guidance or finding objects anymore. I can focus on the imaging.

Hi I wanted to show some images off the 2 new Tamron Lens I got when I recently changed to a full frame camera. I researched for ages to find a fast wide angle lens. I found it pretty hard to find sample images of Astro shots for the lens I was interested in. Plenty of Landscape shots, but very few of stars. I hope these images help others who may be considering either of these lens. Here's the unprocessed images straight off the camera with my 2 new Tamron Lens. -( Canon 6D Full Frame ) 1st image is Tamron 15-30 2.8 lens @15mm 20 sec exposure iso3200 ( I added +0.75 Exposure in Photoshop just to make it easier to see) 2nd image is a crop of the corner of the image. You can see a bit of star movement but very little coma considering the lens is wide open at 2.8. 3rd image is Tamron 15-30 2.8 lens @30mm 8 sec exposure iso3200 (+2 Exposure in Photoshop) 4th image is Tamron 28-75 2.8 lens @ 30mm 8 sec exposure iso3200 (+2 Exposure in Photoshop) 5th image is Crop of the Corner -Tamron 15-30 2.8 lens @30mm 8 sec exposure iso3200 (+2 Exposure in Photoshop) 6th image is Crop of the Corner -Tamron 28-75 2.8 lens @30mm 8 sec exposure iso3200 (+2 Exposure in Photoshop) Coma is a bit more noticeable at 30mmFL. You can see the 28-75 has a little more coma than the 15-30 but both seem pretty good. I'm really happy with both lens which are quite usable wide open at 2.8. That's pretty Bright for a Zoom Wide Angle, and along with the 6D's quite low noise, it opens up some quick and easy landscape milky way shots without my tracker. I generally take 4 shots and stack to get a little lower noise. So when I don't want to set up my Star Tracker Ive got a good option.

Another free option is Siril. I moved to it from DSS some time ago

OK thanks for that. I had suspected something like that. Its a big ask I guess for a scope or lens to cover that big a sensor with min distortion and vignetting. I decided to stick with my crop sensor, driven mainly by my lack of good lenses to use with it.

Hi I use a 550d (APSC) on an Orion 8" F3.9 which works well. Ive got the opportunity to get a full frame DSLR for Landscape etc and wondered if it would work well on my scope Has anyone used a full frame DSLR on this scope. Vignetting? More coma in corners? Thanks

Ha I hear ya on the dragging the tracker up a hill. Its a commitment alright 🙄. Yeah I was considering the Tokina. Looks good, except I was put off by the corners. I saw some images where there was crazy coma in the corners. Stars looked very stretched and had wings! Looked like birds around the edge. Shame, cause the middle was nice and sharp. Also I had a peek at your widefield images, very nice . Particularly good foreground in your shots

I use Siril now (I used to use DSS ). I usually take 4 x approx 2 minute static shots of the Landscape ( Stars have drifted of course) Then I turn the tracker on, and take around 14 x 3min images of the stars (Landscape is blurred). Then I stack the 4 land shots and process a bit. Then I stack the 14 star shots and process a bit. Now I merge them in Photoshop. Because of the sky rotation I have to crop it a bit, but there hasn't been too much movement in the sky over 40 mins or so. So although I've cropped and moved the sky part of the image a bit, the overall image is fairly true to how the scene looked

Thanks. Yes Ive tried Sequator before and its fine, but I prefer other programs for the stacking. So you have done 14mm on FF -thats very wide indeed. Good to hear that it stacked well. Were they tracked images or static shots of shorter length (rule of 500 imaging) I normally aim for 14 x 3 min exposure on my kit 18-55mm lens (used at 18mm) Looks like I'll be OK to get a wider lens although the options are a bit limited for APSC - because I also wanted a zoom range ~10-20mm for daytime landscape photography as well.

And to be clearer, Im talking about Landscapes (foreground mountain or Lake) with milky way in the shot

Alignment before stacking?? I feed the images to DSS (previously) and it does the alignment. I guess you are talking about the more manual alignment as done in PI ??

Thanks I'll try my older dithered data with Siril and see if it handles it first, and if Im not successful I'll put the images up. Note that when I say dithering, I mean huge dithering on my widefield On my usual deep sky rig I do dithering with APT and PHD2 as usual. But when I travel and do widefield I use my Stepper motor driven Scotch mount, so Dithering ( I use the term loosely) is me stopping between frames and moving the camera as small an amount as I can and then carry on tracking. Its pretty punk and ends up with large movements between shots, so if I was to be able to stack successfully I would crop quite a lot. But as I say its not successful so far, so now I don't 'dither'.

Thanks for clearing up the terminology and describing what I had a dim understanding of. I have used ICE before and yes its quite good but still struggles on edges of image. Plus I was hoping to capture the image in one go. I usually travel for my wide field shots and I get a few subs which takes time, and taking more for mosaics will make the already long night longer. I'll have a look at those softwares. Ive used APP before but only for deep sky. My experience with DSS has been that it doesnt stack dithered widefield images well. Thats what led me to my current process of not dithering between images, so images are already perfectly lined up before they are stacked. - do you have to select a special setting? I currently use 'Siril' for stacking which I believe is a version of Iris, but again Ive only used it for deep sky. I'll try that also. Thanks for the input...Have either of you imaged with a very wide lens?

Hi I was looking at getting an ultra wide angle lens for my APSC canon. Then I wondered if I could successfully stack with it. The widest Ive stacked on is 18mm. Which works out well. It seems to get progressively harder the wider you go. Any movement between frames means you cant stack because of field curvature in the lens shifting the position of the stars in the outer corners of the image, meaning the stars wont line up in a stack. So dithering is out. This is the only setup I use darks in, to help a little with noise. So I'd love to hear from anyone who has successfully stacked down to 10-12mm on APSC. - Is it possible? I really would like to stack for a smooth image, as I find the single shot images I see of the milky way a bit to crunchy for my liking. Thanks very much

+1 for Siril

Hi Just thought I'd share this problem Ive mostly worked through. I was having problems with APT and my Canon DSLR (550d). Eg. On some imaging sessions I found that the first 20 images or so were right side up and then the last 10 were inverted. Not a huge problem as stacking programs will rotate them for you. But I saw an issue on a post where Flats were inverted compared to Lights, and of course the Flats did not work. -My problem was, when I manually framed a previous nights image with the framing tool,- then intermittently, the framing pattern was upside down. Also this inverted image issue was reflected differently across different features of the Program. Could get very confusing. It took me a while to realize the images were flipping when the mount had rotated round enough to make the camera body upside down (or at least leaned way over- close to upside down) Disabling image orientation in-camera does not fix this. It turns out its an issue with APT - see this post and look at last few posts where it gets fixed. https://aptforum.com/phpbb/viewtopic.php?f=5&t=1053 The orientation of the camera was not being properly read off the RAW images, but interestingly was OK on JPEGs (the initial workaround was to capture images in RAW+JPEG) So the fix is to install 3.86.7. You need to google "Astro Photography Tool beta 3.86.7" and install it. It works well. -- with a small BUT. One remaining issue that still hasn't been sorted is when you use IMG- Preview Effects while live view focusing, to flip the image intentionally -say to frame an image that was previously upside down- then the orientation works well, but then when you click 5x or 10x zoom, that orientation is not applied to the liveview zoomed image. But that's a special case perhaps not come across often. And Ive just seen that IVO will look at fixing that in the next revision. Hope this helps someone.

Hi. Yes APT does flip images. Disabling image rotation does not fix the issue(maybe different on some models but not on my 550d) I was on their forum and the thread is here. https://aptforum.com/phpbb/viewtopic.php?f=5&t=1053 - go to the end to see the last few posts. They have mostly fixed the issue in version 3.86.7. In order to update your version just google- Astro Photography Tool beta 3.86.7 and install it. The orientation of the camera was not being properly read off the RAW images but interestingly was OK on JPEGs (the initial workaround was to capture images in RAW+JPEG) One remaining issue that still hasnt been sorted is when you use Image preview, while live view focusing, to flip the image intentionally -say to frame an image that was previously upside down- then the orientation works well, but then when you click 5x or 10x zoom, that orientation is not applied to the liveview zoomed image. But that's a special case perhaps not come across often.

Similar to 'wornish' manual alignment procedure. You can also try File, Scripts, Load Files into Stack. Then browse to the 2 images and load them. Then check "Attemt to Automatically align source images" and hit OK. It will load both images as 2 layers and most times they will be aligned very well. Do the 50% opacity technique as above to see if they are.

You mention having stuck to the same tutorial and techniques over the first year of processing. Look around alot more than that. Watch a whole lot more tutorials to inspire you, and I found I just focus on one issue at a time. Having trouble with colour in image - search that, and solve that issue. Then move on,- best way to use curves. Or getting background colour balanced. Read widely Also, I used DSS for ages but was never happy with it. Pixinsight is great but I now use 'Siril' for stacking and initial processing because I'm cheap (its free) and it is very good IMO.