DMK41 - DMK51 Frame size difference example

[Ken Crawford]

Hello,

I did just remember that I shoot first with the DMK41 and then inserted the DMK51. I had to install the 51 drives so not perfectly lined up but I set the left lower and bottom edge. This will give you the difference between the two chip sizes. It is also amazing how much the prom changed in that short time.

[Montana]

Excellent! thanks for the comparison.

Great prom shots, they look great together.

Alexandra

[Ken Crawford]

I am liking it so far. I guess I will have to image 25% longer to get the same number of frames as the DMK41 but in my DSO world of several hours, Solar imaging of another minute is nothing.

I would also guess that you would have to image a bit longer than that to get the same S/N on the faint filaments. But again, with my video processing system it eats these frames no problem.

[solarchat]

Ken,

I have found that about 300 frames is more than enough to get the same result as 2000+ frames with the DMK51. I use 90% quality in registax and always search for the sharpest frame before choosing an alignment poin. I was frustrated at the slow frame rate at first until I just shot a 200 frame avi and got the same results I was getting with 2000 frames..

[Ken Crawford]

That is very intereting. Because of my poor mount, I don't normally shoot more that 700 frames (moves around too much) and I have normally use the best 20%. I am happy with the results I am getting so far but it is good to know the best practices.

In fact, that would bring up another thread - you need to do a best practices for best results. I know I am only using abut 10% of Registax power and relying on my processing skills to make up the difference. I have never been happy with my final stack in registax as it never looks as good as my sharpest frame.

Some help there would be appreciated!

[solarchat]

wow...if your stacked image is not about 100 times better and sharper than your sharpest frame than we need to talk man:) Do you mean before you apply wavelets?

[Ken Crawford]

wow...if your stacked image is not about 100 times better and sharper than your sharpest frame than we need to talk man:) Do you mean before you apply wavelets?

Yes, before I apply any sharpening. The S/N is great but it is not as "sharp" as my "gold" standard frame I pick to register with. I know I am throwing quality away some how.

Would love to get on the phone with you and get some Registax setting, methods pointers. I know just enough to get out what I have been doing so far.

[Pedro]

Thanks Ken.

Great comparison image.

best regards

[Pedro]

I usually record 1500 to 2500 frames and stack 500 to 1000 frames (DMK41 and Skynyx 2-0M). It is very important to choose a good frame before starting the alignment procedure.

Another important thing is to change the middle value in the wavelet button. The default value is 50 (I change it to 1000 or 500). By doing this you can bettercontrol the wavelet filter layers (Usually I use inthe the first 3 or 4 layers).

I also use Registax 5 most of the time. Registax 6 is also great but if you get bad seeing or clouds the results are rubbish.

best regards

[Bill E.]

Ken, I like your comparison. But I can't tell if the 51 has a better quality picture than the 41. Is it just larger?

[Ken Crawford]

I usually record 1500 to 2500 frames and stack 500 to 1000 frames (DMK41 and Skynyx 2-0M). It is very important to choose a good frame before starting the alignment procedure.

Another important thing is to change the middle value in the wavelet button. The default value is 50 (I change it to 1000 or 500). By doing this you can bettercontrol the wavelet filter layers (Usually I use inthe the first 3 or 4 layers).

I also use Registax 5 most of the time. Registax 6 is also great but if you get bad seeing or clouds the results are rubbish.

best regards

I don't have a problem with the wavelets ( I do like the linked wavelets) and I also combine with some decon.

What I do want is a sharper master frame before wavelets if possible.

[Ken Crawford]

Ken, I like your comparison. But I can't tell if the 51 has a better quality picture than the 41. Is it just larger?

Well, the 51 has smaller pixels so a bit finer sampling but the information may not be fully recoverable depending on seeing and the focal length used at the time.

I will have to look for something I can compare between the two. The problem is the solar details are changing fast enough that they are different between the two images that were taken about 20 minutes apart. Also to be fair I would have to use the same amount of frames, ect.

I will give a look to see what I can find. My sense is that I like this camera a bit better for resolution and details but you will need a few more frames for the faint filaments for good contrast and S/N.

[Pedro]

Hi Ken:

To get a sharper master frame you might want to create a reference frame using 50 to 100 images. This can only done with a single alignment box (in registax 5). Usually I use several boxes. In Registax 6 the alignment procedure is completely different.


This is my workflow
HIGH RESOLUTION IMAGING (SUN, MOON, PLANETS)

Acquire high resolution images
Save AVI files or SER files (12 bits) (SKYnyx cameras)
Open Registax 4 http://www.astronomie.be/registax/
Select AVI or SER file
Choose best frame (manually)
Choose alignment options (alignment box) using Gradient as quality estimator
Align images
Limit the number of images to add
Create a reference frame (50 to 100 images)
Optimize images
Stack images
Process the combined image using the Wavelet filters
Reset the Wavelet filter (500 to 1000 center value)
Use layer 1 and 2 of Wavelet filter (try several options)
Process image (DO ALL button)
Save image (16-bit TIFF file)
Process TIFF file in Photoshop
Use Curves to adjust contrast and brightness
Use unsharp mask if necessary
Save the final 16-bit TIF file (no compression)
Convert to 8-bit and save JPG file (no compression)

best

[JimLafferty]

Boy we all do things a bit differently lol. For shots with the 2.5x powermate I usually shoot about 2700 frames with the DMK41 and use ~200 of those. With full disk shots its usually ~180 or so out of about 1800-2100 frames. With very few exceptions I use Avistack 2.0 but I do use the wavelets function in Registax 5.
Jim