Elephants Trunk Re-Visited

[Rodd]

I reprocessed some older data (if 2 weeks can be considered old--for me it is!).  This image consists of alittle over 5 hours 40 min Ha, and 80 min each of RGB.  Ihave a narrowband version of the ET that has about 14 hours but that one will take me a bit longer to re-process.  Color ballance in this image was done using Nebulosities automatic color balance-which is considered a good tool by Nebulosity folks.  I am stll wondering how to get that amazing clarity of detail I see in photos posted on this forum.  Don't know what else to do. 

Thanks

Rodd

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[ChrisLX200]

You should always list the equipment used to capture the data, either in the post itself or in your sig. It helps us offer advice ;-)

Sharpness of detail is usually down to focusing technique (but may be limited by the type of OTA used).

ChrisH

[Rodd]

Here's the same data processed the old way--unknowingly saving the STF data after an auto stretch.  Obviously, I am still missing something.

[Rodd]

I shot this with a Televue np101is, Astrophysics mach1, SBIG STT-8300, Baader filters.

[ChrisLX200]

I shot this with a Televue np101is, Astrophysics mach1, SBIG STT-8300, Baader filters.

OK, well I would expect the NP101is to do better so maybe it is down to focus - what method do you use? Ideally you really need an autofocus system to get the best out of a great OTA like that.

ChrisH

[Rodd]

For the Televue I use a Bhatinov (sp?) mask--which gets me pretty darn good focus.    When I image in focus mode at stars I get pin pin point stars.  I spend  a bit of effort getting good focus.   My Ha subs are extremely clear out of the gate--except camera noise is bad on any single sub when I look close.  I shoot at -45, which the camera has held very well using only 55-60% of its cooling muscle.   The stars in the pics have been processed with Nebuloisities version of deconvolution.   If you look at some of my Heart Nebula pics on the other forum I stared you will see some of the dust lanes and small details that are extremely clear by themselves--its the rest of the pic that is bad I think.  I would be surprised if I got a focuser and see a huge difference.  Remember--my processing skills are in the root cellar beneath the basement.

[Rodd]

Pictures appear grainy.  The printer said they are 72 dpi--I would like to print out a pic but teh resolution is so low its not worth it.  8.3 mp should get higher resolution.

[ChrisLX200]

A suggestion from me would be to look at a different processing package - StarTools. I find it much easier to learn to use (more logical process structure than, for e.g., PixInsight) and the noise reduction algorithms are second to none. There is a free trial (IIRC you just can't save - but can do a screen grab). It's really quite inexpensive too.

http://www.startools.org/

ChrisH

[Rodd]

Thanks Chris--I'll look into that.  certainly not wedded to Pix-- though I have spent some $ on tutorials and time learning it.  Need rock climbing gear to battle the learning curve.  However--maybe the autofocus is needed--I don't know.  Compatibility is always an issue and they can run to $1,000.  Would motorized focusing really be that much of a improvement?

[ChrisLX200]

Thanks Chris--I'll look into that.  certainly not wedded to Pix-- though I have spent some $ on tutorials and time learning it.  Need rock climbing gear to battle the learning curve.  However--maybe the autofocus is needed--I don't know.  Compatibility is always an issue and they can run to $1,000.  Would motorized focusing really be that much of a improvement?

It's difficult to say without examining your raw data but there are a couple of things I DO know - 1) your 101is is capable of extremely sharp images, and 2) I could not work without autofocus.

ChrisH

[libraryman]

Has this image had any flats applied, I can see at least one satellite trail on the right, I wonder if flats or lack of good flats and calibration could be a factor?

Ray

[Stub Mandrel]

A suggestion from me would be to look at a different processing package - StarTools. I find it much easier to learn to use (more logical process structure than, for e.g., PixInsight) and the noise reduction algorithms are second to none. There is a free trial (IIRC you just can't save - but can do a screen grab). It's really quite inexpensive too.

http://www.startools.org/

ChrisH

The website suggests it's pretty impressive for about £30!

[Davey-T]

As per Rays comment has it been calibrated ? doesn't look like it if you zoom in.

Not sure about Nebulosity colour balance, looks like the same effect as on your Heart image, red to green diagonal colour cast ? may be "real" haven't done RGB on Heart or ET only NB

Dave

[Rodd]

Not fully calibrated--a master dark consisting of 21 dark frames.  I usually take the satellite subs out, but I did not want to lose the data and they did not cross the trunk.  No flats or biases.  I do know the 101is is great, as the AP Mach1--I am wondering about the camera--STT-8300.  It should be at least decent.  I have seen pics taken with the 101is and the STT-8300 and they are awesome.  Something is definitely blowing the sharpness.  I don't know enough about processing to know if it is because the image has not been subjected to a "full treatment" or not.  

[ChrisLX200]

Not fully calibrated--a master dark consisting of 21 dark frames.  I usually take the satellite subs out, but I did not want to lose the data and they did not cross the trunk.  No flats or biases.  I do know the 101is is great, as the AP Mach1--I am wondering about the camera--STT-8300.  It should be at least decent.  I have seen pics taken with the 101is and the STT-8300 and they are awesome.  Something is definitely blowing the sharpness.  I don't know enough about processing to know if it is because the image has not been subjected to a "full treatment" or not.  

Well OK then, try downloading the file linked below and process it the way you normally do. I know how this should turn out, what you end up with will tell me a lot about your processing and how much it is affecting your end result.

https://www.dropbox.com/s/1alayoxdwqmry56/Autosave%20ic1396.fit?dl=0

ChrisH

I should have said - it's an Ha stack of ic1396, already callibrated with flats and bias (no darks - doesn't need them).

[Rodd]

I will do that--probably won't be able to get to it until tomorrow though.  I will post the result here.  I will predict that the image will look much better than mine with little processing due to the starting point being better, whatever is plaguing my images will not be contained in these.  But the end result will not be very good because I don't know how to process.  Maybe I'm shooting too long for the conditions (20 minutes).  Maybe some setting in the camera is still not right but I have been over the manual and the camera with a fine tooth comb).  

Thanks for the interesting exercise--all your input is valued greatly

[Rodd]

Thats cool--tonight I am going to do a bi color of the Heart because I gout one of those Neumann flat foils so I can finally shoot flats, and I have to shoot less then if I go full HaRGB  I am going to do advanced calibration per AIP4Win becuase I have it (its a processing software from a very good book). It has a very good calibration system.  I will be able to use my master dark (21-20 minute-minus 45 degrees), flats, flat darks biases, the works.  The darks will be scaled.  I usually shoot at 1200 sec, but tonight I intend to stack more shorter exposures so the dark has a longer exposure time than my lights.  Also, shooting 20 minute subs has not served me particularity well, so why not try 600 sec (or even 300 sec).  I have mixed feelings about this--especially with Narrowband.  But I have a full Hubble Pallet photo with 14.5 hours of 20 minute subs of the Elephants trunk and it is no better than my other pics.  So, tonight will allow for several comparisons,

1) It will shed some light on whether the lack of full calibration is the culprit, or how much it contributes,

2) It will provide some data for me regarding sub exposure lengths, and whether I really need to shoot 20 minutes all the time.  Instead of 6 20 min  subs of Ha and SII, I'll be able to get 30 4 min subs each--maybe 24 5 min.  I don't know.  Maybe 2 40min.

3) There will be a better comparison with the bi-color pics of the Heart I've seen on this forum--providing for a better understanding of what I am doing wrong.  Except for maybe the camera, I think it is safe to say it is not the equipment.  

4) Even though it will be narrowband, it will provide at least some comparison with various aspects of my own HaRGB heart (resolution primarily).

That's the idea anyway

[Davey-T]

I have an old version of AIP4Win that I had trouble with opening the saved files in other applications, excellent book though

Dave

[Rodd]

Well--a long night that was both fruitfull and fruitless.  For some reason when I use the Bias frames and flats (flats and flat darks for each filter), the stacked images come out unstretchable--no data appears after significant stretching.  Its a shame because the Neuman flat field illuminated foil worked like a charm.  I must be somethin I am doing wrong--but I tried it in both programs and even manually (that was an endeavor).

So, I am left with a HST pallet of the Heart.  Televue np101is, .8x reduecr, AP Mach1, 70 min Ha (11 x 5 & 1x15), 70 minutes SII (11 x 5 & 1x15), and 85 min OIII (11 x 5 & 2x15).  Master dark consisted of 21 20 min frames.  Everything shot at -45C.  My intent was to use the advanced calibration of AIP4WIN, which scales the dark with bias and the darks are longer then the light iterations.  Since I actually did the basic calibration (just used a master dark), the dark iterations should have been the same as the light frames.  Oh well, too much work to not try it.

Here is the pic--cool in a way, but the resolution issue has not been solved.  Zoom I and your confronted with garbage.

[Rodd]

Maybe its the camera?

[Rodd]

Well Dave--I finally got the flats to work 9not the dark flats though--I think I took those wrong, that's why they did not work).  The attached image is the same as above, though calibrated with a scaleable dark (master dark and master bias), and master flat.  What do you think?

[libraryman]

What's your image scale? The stars look a little blocky when I zoom in, big ones o.k but the smaller ones look too blocky to my eye, perhaps a s5ar reduction routine might assist!

Also I don't see the small nebula WeBo 1in your image but that maybe due to lack of O111.

Looking a bit better though.

Ray

Edit...I'm going to correct myself here, I wonder if this is a stacking issue or a registration issue! When zoom in really close, I see what appear to be some very close diffraction spikes that may indicate a stacking problem leading to the poor resolution!!

Just shooting ideas!

Ray

[Davey-T]

I think it's looking better, at least you've fixed the blown out highlights, onwards and upwards, no one said it would be easy, hmm reminds me of a song 

Dave

[Rodd]

Not sure what you mean about image scale--I open the pic and work on it.  When its small on my screen it looks good.  When I increase magnification it blows.  I don't think its stacking--I have stacked and aligned in both Pixinsite and nebulosity and that seems to work fine.  There is something going on that I can't figure out.  Here's another version after more processing--Resolution is still terrible, but I ran a star tightening program and a unsharp mask at low intensity.  Now I am off to bed--I was up till 5:30 at the scope and worked all day on this pic.  Can't say I'm feeling satisfied.

[Rodd]

It looks worse the next day.  Can pics degrade in electronic format?  It seems to me that all the details are present (ie. Melotte 15 at center)--its almost like they are covered over with a blurring film.  It appears exceedingly noisy to me.  I don't know how else to get noise out--delta temp was -45C, master dark, bias, and flat were used.  I tried noise removal in all available forms (only 2-3 in Nebulosity).  Guiding was good.  Its either due to ineffective processing or something about the camera--with maybe 5-10% due to focusing--need a motorized focuser I guess--but which one?.  Maybe its due to a combination of focus, camera not being perfectly square, poor processing, sub par camera (either due to operator ignorance or a bad chip--suppose to be grade 1)--don't know what else it could be.  One thing is for sure--its not due to how I was saving the files, and flat frames were not the fix (though they helped).