How To Use A Wedge For Astrophotography

Рет қаралды 5,826

Күн бұрын

This is the video I wish I had seen when I first tried to set up a wedge. I go over the key concepts you need to know in order to understand and use a wedge properly for astrophotography, including the Meridian, Celestial Equator, Polar Alignment, Wedge Angle, and Leveling Your Mount. I talk a bit about the Celestron wedge as well.
Update: I've been thinking a lot about the mount rotation in the z-axis. In fact I had several edits of this video where I pointed out that you actually could compensate for horizontal tilt in most cases. Here's an example of an extreme case: you are at latitude 10 North, and your mount is tilted to the side by 10 degrees. In order to properly line up to the Earth's axis, you would have to turn your mount 90 degrees and set your wedge to 0. Same situation in the North Pole? There is no combination of adjustments to declination or azimuth which would make your wedge plane perpendicular to True North. However, if you are somewhere between the Equator and either pole, and your tilt is slight, then you could compensate by rotating your mount (azimuth) and adjusting your declination angle. The biggest problem with this is that if your mount is tilted, then you are no longer adjusting in one dimension / direction when you make declination adjustments. Every adjustment up or down also slightly shifts your orientation left and right, making alignment a real headache. Please level your mount side to side before you start! #astrophotography #wedge
Thanks for watching, and clear skies!

Пікірлер: 33

@IslandSkyPhotos 13 күн бұрын

This was so incredibly helpful!! I just mounted my 8SE on a wedge and had no idea what I was doing when I tried my first polar alignment. 😂 I really appreciate you giving such a simple explanation and helping us newbies understand!

@Felldisulfide 12 күн бұрын

@IslandSkyPhotos thanks for the comment, I'm glad the video helped! Most of the online forums were so focused on where to measure degrees from that they didn't really cover the why and the how. Good luck with your scope, and clear skies!

@reneantoniourrozalvarez3693 Жыл бұрын

Thank you very much for this very simple and useful video. I just got started in the ways of astrophotography and I bought a Celestron wedge for my NexStar 6SE. And no matter how much I followed other videos and Celestron's guide, it was impossible to configure it properly. With your help the whole vision and configuration changed and made sense and a lot of logic. Tonight I'm going to follow all your recommendations and I'll tell you how it went. Again, thank you so much for taking the time to help. My personal thanks.

@Felldisulfide Жыл бұрын

Glad to help! My own frustrations with wedges led me to start this channel. If you are using CPWI, definitely perform the All Star Polar Alignment (ASPA), it is very easy to do and will make a huge difference to your alignment. Also, expect to get exposures in the 15-30 second range. Without guiding, the right-ascension drive on the NexStar is not as accurate as it could be (at least mine is not), so at your focal length of 1500mm anything longer than 30 seconds is likely going to leave star trailing even with the best alignment. Good luck, and Clear Skies!

@m1thumb 10 ай бұрын

Oh no! Not the dreaded wedge! Actually been using it for a while and it works well. The weak link is the mount, although more capable than many give it credit for. Good video.

@Felldisulfide 10 ай бұрын

Thanks! My mount works great for visual, but needs guiding for anything over 30s. I've heard others have had luck with up to a few minutes, but when I turned off guiding recently I learned my mount has a periodic wobble in the azimuth every 50s or so. Clear Skies!

@m1thumb 10 ай бұрын

I haven't done a lot of imaging, mostly planets but recently started guiding. Watched a couple of your vids, one on drift aligning which should help as soon as the clouds clear. My RA is usually 1.3-1.5 but dec has been very erratic.

@Felldisulfide 10 ай бұрын

Drift alignment made a huge difference for me. I often skip ASPA and go right to drift alignment. It gets easier once you get a sense for which way you need to adjust the mount based on the drift direction. One thing to keep in mind if you use something like PHD2 is the drift direction (North/South) is the drift of your mount in relation to the guide star, which is the inverse of the star trailing you would see in photos.

@LE018_07 6 ай бұрын

Hi, great video congrats, I'm in Chile my lat is 23.4° south my complementary angle must be?

@Felldisulfide 6 ай бұрын

Hi Leo, if you are measuring from the base plate, then your wedge angle should be at 66.6 degrees. If you are measuring from vertical, then it would be your latitude of 23.4. Either way, the complementary angle is against 90 degrees (the right angle between the horizontal wedge plate and the vertical plane) i.e. 23.4 + 66.6 = 90 Clear Skies!

@LE018_07 6 ай бұрын

@@Felldisulfide thx mate

@Noah-kc2ws 6 ай бұрын

Hi, I have a celestron heavy duty wedge, I am from Toronto, Canada, my latitude is 43 degrees, from your example, 90-43 =47 degrees, should I set my latitude 47 degrees on the L side knob (facing east)?

@Felldisulfide 6 ай бұрын

Hi Noah, the Celestron wedge is labeled according to latitude, not angle from the base plate. For example, if you were to set your wedge completely vertically, the orange measure will read 0, meaning you are at the equator, not 90, which is the angle. You should set the wedge elevation to read 43 degrees on the orange measure to match your latitude. If you do that, the actual angle between the wedge and the base plate will be 47 degrees. CS!

@Felldisulfide 6 ай бұрын

This holds true for the Wedge HD as well which it sounds like you have.

@ankurmishra3054 29 күн бұрын

Hi, new to the channel. I would assume the process is similar for southern hemisphere, but I guess the advantage of a pole star is gone?

@Felldisulfide 28 күн бұрын

@ankurmishra3054 yes, the process is pretty much the same except you would be pointing your OTA North towards the Prime Meridian, not South (using a wedge). There are a few constellations astronomers in the Southern Hemisphere use to help with alignment, such as the Southern Cross, but nothing as simple as Polaris. There are also apps that can help you point your wedge in the right direction. I think you would need to get comfortable with drift alignment in order to fine tune your alignment once you have it more or less oriented based on the other methods.

@ankurmishra3054 28 күн бұрын

@@Felldisulfide thanks a lot 😊

@awoytb1720 11 ай бұрын

Is that the same thing if only use the hand controller cause I always have 7 minute of arc on mine ?.

@Felldisulfide 11 ай бұрын

The same principles apply, however you won't be able to use ASPA or Drift Alignment (PHD2) to fine-tune your alignment. If you are using only the hand controller, then I would suggest you pick a star along the Meridian as the first star of the EQ North/South align, then adjust your AZ and Declination on the wedge to center the star. The problem you'll run into is that you won't have any way of knowing if your OTA is level (the little sticker is not accurate), or if your mount is pointing exactly at the Meridian. It might take you 3 or 4 alignments to improve your orientation. For example, if your scope is perfectly level side to side, you pick your second alignment star to the left, and find that your scope is pointing too low, then your azimuth might be too far to the right.

@awoytb1720 11 ай бұрын

@@Felldisulfide is that possible for me to show you on a video how I do ?

@Felldisulfide 11 ай бұрын

I have not yet figured out live streaming, but if you want to post a video of your workflow to your channel, I would be happy to review and comment. What equipment are you using? If you are using the hand controller, I assumed you were imaging with a DSLR, otherwise you would have needed a computer to control your camera.

@awoytb1720 11 ай бұрын

@@Felldisulfide No No i mean where i can speak with you in private so i can show you and you can explain cause youtube is not make for this.

@Felldisulfide 11 ай бұрын

Sorry awoytb1720, there's no way to do that while remaining anonymous/without sharing contact info. Let me know if there's any other way I can help you. If you are interested, I'll put together a video of how to get your scope polar aligned with just a hand controller. Let me know your setup so that I can use a similar config.