M51 Image Solve Issue

Theodore Mitrou

I have been using Pixinsight since January and have Stretch Academy and most recently Fundamentals. (I'm ready to learn more about how Pixinsight works behind the scenes.) Adam, you are one of the best instructors I have ever subscribed to.

After learning about 'superpixel'  debayer, using WBPS I was able to get over 150 images of M51 over a 4 night period to register and align perfectly whereas before I had to manually align the masters from 4 nights. I was thrilled. However, when I tried to image solve, it failed. I have used image solver many times before successfully. There seems to be enough stars (it finds 72) but get 0 pairs and fails.

I have used Blurx to tweak the stars but that didn't help. I assure you that the RA and DEC are perfect (it plate solved on astrometry.net); I used that RA and DEC as well as the pixel scale for image solver so that isn't the issue. 

Since this is a long focal length (2367 mm to b exact) I realize my stars are a bit bloated and perhaps thats the issue. 

Do you have any suggestions to get this image to plate solve so I can use the color calibration tools as I move forward.

The image is untouched as it came out of the Master Light except for an unlinked autostretch( except I added the M51 to the name )

Thanks in advance for any advice....

Ted

Theodore Mitrou

Well, I just solved my own problem. Since I debayered with 'superpixel' mode in WBPS, the pixel scale of the image was actually ,572 instead of .286... (I have used .286 forever during processing with my 9-1/4 Celestron.) This was the first time I ever used the 'superpixel' mode to solve a registration problem. 

When I used astometry.net to verify the position, I used the image that I had formerly processed (at .286). I didn't realize that the image created using the 'superpixel' mode had a different pixel scale although Adam did point out the difference in image size in his tutorial. Seems simple now that I know the answer...

Ted

BlockHead

Exactly. Superpixel does not interpolate between pixels. 

I will say you will want to be a little careful with superpixel. Since there is no interpolation- your images will be noisier. Interpolation acts like a little bit of a noise reduction. I just want to point this out so you are not surprised if you compare at some point. Noise reduction like NoiseXTerminator can likely offset.

Good job thinking like a Blockhead...

-the Blockhead

Theodore Mitrou

Thanks for your comment. Appreciate it!