This is odd... dss problem please help

rnclark · Jan 19, 2016

Jon Rista said:
Roger, before I even get into this with you, I don't know what you are trying to pull, but you seem to have purposely butchered my image in the comparison with yours. Whatever you did to make that comparison look that bad is completely unethical. THIS is how my image really looks:

Rogers image in comparison to a butchered version of my own!! WTF?

I am not even going to begin having a conversation with you about this if you are going to screw around with my image like that, and try to purposely present it in an unreal and unfair light. That is beyond screwed up!

And again, you are SIGNIFICANTLY downsampling the data here, which is hiding the true nature of the noise in your image. I've shared my image at 100% crop, so there is no additional smoothing of noise due to downsampling. I am not even going to touch your image to provide my own comparison after this, though...good god.

The image comparison above is from an image you posted here from one of our previous conversations:

Canon 60Da or 'full frame' better for astrophotography?

I'm sure I'll get flamed now.... No flame, but your reviews are always strictly Canon centric. Where's a review for the Nikon D5100, D5300, Sony A7s, etc. ?? Sorry, my bad here due to the fact my opening question being about Canon equipment as that is what i have and was not aware of other...

www.dpreview.com

The area in the comparison is from the upper right. A simple curves stretch shows the mottling on your posted image. Glad to see you've improved and reduced the mottling with more recent processing.

Roger

Sir Canon · Jan 19, 2016

i am done with all the arguement. i want to lock this thread so there can be no more posts but still want it to be visible for educational purposes (ie not deleting it)

ChrisLX200 · Jan 19, 2016

Sir Canon said:
i am done with all the arguement. i want to lock this thread so there can be no more posts but still want it to be visible for educational purposes (ie not deleting it)

--
I tend to overdo things

There is more mis-information than education going on in here, with Jon trying his best to bring some sanity to it all.

ChrisH

Sir Canon · Jan 19, 2016

indeed! but it all needs to stop. this may be the most responded to post in the ap fourm :-O

Jon Rista · Jan 19, 2016

rnclark said:
Jon Rista said:

Roger, before I even get into this with you, I don't know what you are trying to pull, but you seem to have purposely butchered my image in the comparison with yours. Whatever you did to make that comparison look that bad is completely unethical. THIS is how my image really looks:

Rogers image in comparison to a butchered version of my own!! WTF?

I am not even going to begin having a conversation with you about this if you are going to screw around with my image like that, and try to purposely present it in an unreal and unfair light. That is beyond screwed up!

And again, you are SIGNIFICANTLY downsampling the data here, which is hiding the true nature of the noise in your image. I've shared my image at 100% crop, so there is no additional smoothing of noise due to downsampling. I am not even going to touch your image to provide my own comparison after this, though...good god.

Click to expand...

The image comparison above is from an image you posted here from one of our previous conversations:

http://www.dpreview.com/forums/thread/3878921?page=2

The area in the comparison is from the upper right. A simple curves stretch shows the mottling on your posted image. Glad to see you've improved and reduced the mottling with more recent processing.

Roger

It's not a "most recent" processing, it's the EXACT SAME processing. You threw a curve on a heavily compressed JPEG, which is why it looks like that...you are just revealing JPEG compression artifacts. The original FITS file does not have anything remotely like the mottling your supposedly "revealing" with your curve. You should understand that. What a ridiculous load of crap. This is low behavior, Roger. Twisting and misrepresenting the facts. I've shared a 100% crop of the exact same image, no additional modifications (I can even link the original, that was uploaded months ago...and has been unchanged since)...how about you share a 100% crop of your image. It will be a lot noisier.

Jon Rista · Jan 19, 2016

Sir Canon said:
indeed! but it all needs to stop. this may be the most responded to post in the ap fourm :-O

ChrisLX200 · Jan 19, 2016

Sheesh, this thread is even longer than the Pluto Mountain thread ( http://www.dpreview.com/forums/thread/3608786 ). Think these guys are related? Gave me a chuckle to go over that thread again.. ;-)

ChrisH

WildImages · Jan 19, 2016

Sir Canon said:
i am done with all the arguement. i want to lock this thread so there can be no more posts but still want it to be visible for educational purposes (ie not deleting it)

rnclark · Jan 19, 2016

Jon Rista said:
It's not a "most recent" processing, it's the EXACT SAME processing. You threw a curve on a heavily compressed JPEG, which is why it looks like that...you are just revealing JPEG compression artifacts. The original FITS file does not have anything remotely like the mottling your supposedly "revealing" with your curve. You should understand that. What a ridiculous load of crap. This is low behavior, Roger. Twisting and misrepresenting the facts. I've shared a 100% crop of the exact same image, no additional modifications (I can even link the original, that was uploaded months ago...and has been unchanged since)...how about you share a 100% crop of your image. It will be a lot noisier.

Jon makes some very serious accusations. He says they are the exact same image. They are not, and I was trying to do an honest comparison. Attached is proof the images are not the same, and if you go and look at his original posted horsehead image in the depreview link and the larger one in astrobin, you can see the mottling in the posted images. Below is the same crop from his posted image, as well as the one he posted claiming to be the same. They clearly are not. The star field has different distortions and a rotation. Clearly not the same image. I'm tired of the false accusations here and I am done with this thread.

proof the two images are not the same

Jon Rista · Jan 19, 2016

Roger, I only have one wide field Orion Sword image, one set of subs, gathered once...in December 2014. I've reprocessed it twice, once in December 2014, and once in July 2015. Identical data, same exact subs, different processing techniques. You have already admitted to modifying my image, which was a small, highly compressed JPEG. You cannot assume that a curve applied to a JPEG with compression artifacts is anything remotely the same as that curve applied to original 32-bit float FITS data. You have misrepresented, simple as that.

Compare my image with your image without any modification, at 100% scale...then and only then will we have some truth. I've asked you to show your image without any scaling multiple times, and it still hasn't happened. I assert that your data just doesn't hold up at that scale. I've already shared a full size crop from my only reprocess back in July...you can measurebate tiny little downsampled crops of my image all you want...none of it matters until we see a full size version of your data, particularly that outer dust.

Now, this is the largest version of your image that I could find on your site (http://clarkvision.com/galleries/ga...014.0J6A1631-1657-SigAv.i-b2x2s-c2.html)...as far as I could gather, it's 50% scale? I did not modify your data, I only cropped it. I modified my data solely by scaling it to the same size in a matching crop. No curves, no additional processing, just scaling and cropping:

Here it is with one single modification: I brightened my version a bit to roughly match yours with nothing but a simple levels adjustment:

For the record, you claimed my image is 232 minutes of integration. That is incorrect. The base exposure (i.e. the faint dust) was 2h 20m. That is 140 minutes of integration. The additional integration time listed on AstroBin ONLY accounts for the shorter exposures factored into the Trapezium core...those exposure sets were NOT combined with the original 140 minutes of integration for the entire wide field, including the dust structure pictured above. This, again, is a misrepresentation by you of my data. The second time you have made that same misrepresentation, as a matter of fact, and the second time I have corrected it.

Furthermore, the page I linked above, were I acquired the comparison crop in the images above, states the integration was 27.5 minutes, not 9 minutes. Perhaps there is another Orion Nebula image of yours that is only 9 minutes of integration, who knows. Given that, the ratio of exposure time here is 5x, not 50x. That is a FACTOR TEN difference. Even if you do have a 9-minute integration floating around out there somewhere, and this 27.5 minute integration is something else, it does not change the fact that you have been misrepresenting the facts. Even with a 50% downsample, your data simply doesn't hold up. It is significantly noisier.

I think this all speaks for itself. I rest my case. With that, I'm done.

sharkmelley · Jan 19, 2016

Attempting to clear up the latest confusion here.

Jon has two images containing the same "lump of dust" but with slightly different integration times:

1) Horsehead and flame image (see top right): http://www.astrobin.com/144855/

2) Orion's Sword (left edged): http://www.astrobin.com/142576/F/

Roger's comparison uses a tiny crop of the former. Jon's comparison uses a tiny crop of the latter.

This confusion is probably just another misunderstanding in a thread which unfortunately contains far too many misunderstandings to mention.

Mark

Jon Rista · Jan 19, 2016

sharkmelley said:
Attempting to clear up the latest confusion here.

Jon has two images containing the same "lump of dust" but with slightly different integration times:

1) Horsehead and flame image (see top right): http://www.astrobin.com/144855/

2) Orion's Sword (left edged): http://www.astrobin.com/142576/F/

Roger's comparison uses a tiny crop of the former. Jon's comparison uses a tiny crop of the latter.

This confusion is probably just another misunderstanding in a thread which unfortunately contains far too many misunderstandings to mention.

Mark

If he showed a side-by-side comparison of two Orion Nebula images, then went out of his way and dug up my horsehead nebula image (which had never been previously referenced) in order to compare the two crops of a dust blob that also existed in my Orion Nebula image a moment later, that is no less missleading, and still misrepresenting the facts.

As a matter of fact, he strait up stated in the original post that first showed his butchered version of my image that it was from my M42:

sharkmelley said:
Another thing I learned is that people are employing post processing noise reduction that is making an unnatural splotchy background. Here is an example, again use our M42 images. Notice the red-blue splotchiness in the right image. Again check the similarity of the stars noting that my image is made with half the focal length (so a little less detail) and many times less exposure.

If that was not the case, then the above was a strait up lie. There were significant sky brightness differences between the Orion Nebula and Horsehead images. One was done on new moon (Orion Nebula), the other was done with a 20% moon (horsehead). One was image under 21.3mag/sq" skies, the other with 20.6mag/sq" skies. A difference of a stop in terms of brightness. I reduced exposure by a factor of two for the horsehead image, as it had significantly more light pollution. Apples and oranges there.

Anyway. The final comparison I shared explains everything I've been talking about. SNR is SNR. More of it means you can dig deeper, stretch more, with less noise in the final image. Rogers background details are significantly noisier, far less detailed, and lacking in fine color and tonal gradations. My image has more detail and better color and tonal gradations because it had a higher SNR. Simple as that. It's not rocket science.

Is there way to unsubscribe from a thread?

Sir Canon · Jan 20, 2016

im pretty sure a moderator needs to

RickColman · Feb 6, 2016

Hello?

Sir Canon · Feb 6, 2016

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This is odd... dss problem please help

rnclark

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Canon 60Da or 'full frame' better for astrophotography?

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