ollypenrice

Maybe try a BlurX processing next to a regular sharpening process like Unsharp Mask. The regular routines are basically contrast-enhancers at different scales. If you see anything new appear in the BlurX result then you might, and rightly, consider it spurious. In making this comparison myself I've found nothing to make me doubt the BlurX result. It's essentially the same as the USM only finer and with less noise. It also requires less intervention. My feeling is that it is more, rather than less, true to the object. What I do find interesting is that it seems to find more faint structure just above the background sky. I'm always keen to find this faint stuff and, like another member earlier in the thread, I feel it is enhanced by BlurX despite this not being, on the face of it, what the process is about. Olly

Yes, I need to see if I have any very oversampled 14 inch linear data on an old hard drive... Olly

Certainly use all three, but I'm certain that BlurX is close to offering noiseless sharpennig, unlike any other sharpening routine. Olly

M51, just the lumnance layer reprocesssed from linear with all three Russ Croman routnes working overtime. 5 inch telescope. https://ollypenrice.smugmug.com/Other/Galaxies/i-d5BBZQp/A Olly

Great. To be honest, I think the large amateur telescope has been on the run for some time. Small pixel cameras and this kind of processing get you so near to the big stuff with quite small apertures. Olly

I didn't see this because I was busy reprocessing - yes - the Fireworks galaxy! And you're right, the combination of StarX and Blur X (with a little help from Noise X) has made this into an altogether new prospect. The poor old galaxy was swamped by stars and had lots of little details which got knocked about by regular sharpening routines. I felt I was able, this time, to keep a softer look (my current undertaking) while finding more detail into the bargain. The Ha contribution is very discrete in order to preserve that gentler look but could easily be turned up. This is posted on my gallery at 100%. There are mild JPEG losses but I didn't want to downsample. https://ollypenrice.smugmug.com/Other/Galaxies/i-dhnLzws/A Olly

My Ha for this region did follow the outline of the which as Rodd's does but I also found a band of Ha roughly perpendicular to the Witch, crossing it roughly mid way. https://www.astrobin.com/383965/ I've since pushed the signal a bit harder than in this rendition thanks to StarX. Olly

Sorry, false click.

OK, two results. This is NGC772 reprocessed. Note the full screen icon upper left and click on the image for the largest version. The BlurX images are shown at full size whereas I had to reduce the originals a little. These are all heavy crops from the TEC140/Atik 460. https://ollypenrice.smugmug.com/Other/Galaxies/i-hH2SsDK/A The previous version is below. Sorry about the change in orientation. https://ollypenrice.smugmug.com/Other/Galaxies/i-vDD6Gw3/A Now NGC891. I was always disappointed by this image because I just couldn't get the hairy little strands at right angles to the galactic plane to look right. Using unsharp masking to pull out the detail did a lot of collateral damage. One look at the data directly after BlurX showed that my problem was solved. This is the new version: https://ollypenrice.smugmug.com/Other/Galaxies/i-SZLsvmF/A The original is below. https://ollypenrice.smugmug.com/Other/Galaxies/i-V36HW2z/A In both cases the use of Blur X produced better detail with much less intervention, gave a cleaner result and, while the difference at 100% is significant, at 200% it is staggering. This may also have an impact on print quality. I haven't tried a print, yet. Olly

I've had a first play this afternoon, working on a small galaxy, NGC772. BlurX has improved the image without doubt. It got me a sharper inner galaxy when compared with my original. However, my original had a painstaking sequence of Unsharp Mask iterations of different scales, selectively applied in layers and taking an hour or so to do. The BlurX image beat it after just a basic stretch. As Adam Block points out, the difference is even greater when the image is taken beyond 100%. The BlurX one isn't bad at 200%. I also think it got me deeper into some very faint tidal tails, but I can't be sure at this stage because the first process was a long time ago. I looked hard for fundamental differences in small structures between the BlurX version and the Unsharp Masked version. There are none. The sharpening pulls out the same details but Blur X does it a tad better and with a tenth of the effort (and less noise.) I also made a careful comparison with a professional image of this galaxy and could find nothing to suggest the invention of spurious detail in mine. I'll be buying it. Olly

Humph, I'd like to be trying it, too, but I updated to the latest PI - or tried to - and they are not sending me my new activation code, or not in the 'few minutes' promised. Olly

That's the wrong way round. You should run BlurX first (Adam Block explains why in the video.) Good result, even so. Olly

When we hear that BlurX is trained on Hubble data, that does not mean it is going to apply Hubble data to yours. Clearly that would be cheating and wouldn't work on anything except a target imaged by Hubble. Given Hubble's tiny field of view, that's not going to cover many images. My understanding is that it has been trained to understand the point spread functions of astrophotos using ones of very high quality. From this source of information it can recognize and correct distorted point spread functions in our inferior systems. It does not take any Hubble information specifically on M31 to apply to our M31s. What it takes from Hubble, I presume, is an ideal PSF against which to asses our PSFs. I think this kind of deconvolution is more akin to calibration, which takes me back to my point about understanding the systematic errors of our measurements. (Our photos are measurements of the amount of light, pixel by pixel, arriving from the object.) When we apply darks and flats we improve the accuracy of our measurements by adjusting them to the known errors in our camera noise and our optical illumination. We can, therefore, measure to an accuracy greatly exceeding the natural accuracy of our uncalibrated systems. In a similar (but not identical) way, BlurX analyses our data to identify the distortions and characteristics of our PSFs so that it can correct them. The difference between this and darks-flats is that darks and flats are direct measurements rather than computations. However, they are computations derived only from your own image. That is why the Spanish Inquisition (Pixinsight) have approved the routine. Olly

If you have a way of measuring something to a certain degree of accuracy, and you also have a good knowledge of what your measurement errors are, might you not, in principle, measure with an accuracy which exceeds that of your system? Olly

As a pragmatist I'd be happy to take an image from a professional scope and compare the effect BlurX had on my image of the same target. If it made mine look more like the professional image, I'd consider it valid. If it took my image in some random direction, I wouldn't. One thing I don't need is tightened stars! Since using StarXterminator, I frequently find myself needing to give them a gentle blur.* Say I'm at the stage of having the extracted stars placed over the starless image in blend mode Screen. Since I'm working, at this stage, with a moderately or fully-stretched image, I then de-stretch the stars using Levels in order to reduce them. In order to give them more 'pop,' especially in the case of the now very tiny ones, I simply increase the contrast on the star layer. At this point I often make two adjustments, the first being to blur the stars (Gauss 0.2 to 0.6 or so). This makes them blend into the image more naturally, as does reducing the opacity of the star layer by a very small amount. The other tweak is for any stars which are still 'standing out' from the nebulosity around them in a sharp, un-natural way. Here I activate the starless layer and give the area beneath the stars a dab with the burn tool to give a slight glow around the stars, as happens naturally with optics. So I don't want my stars tightening but having the corner stars made rounder would be nice for the RASA. Olly * Edit: Is this what they call a first world problem?

I like the video method as well but would not want to be removing the camera from the RASA, given how critical its fitment is at F2. You could make a dedicated stand, though, rather like a saw horse but taller. The scope would sit in the vee in the way a log does. You'd want to design it so that it stood on the paving blocks for consistency of height and some range of adjustability would probably be needed to get the dovetail into the saddle plate for the mounting phase. Might it stand on braked wheels for fine manoeuvres? Indeed, I wonder if we might not have invented a telescope accessory for the industry to produce... Olly

Certainly experiment with backfocus. Olly

We might be able to test this by taking a low res and high res image of the same object and running BlurX on the low res one before comparing the result with the high res. Olly

Has to be worth looking into. I do have Pixinsight but consider it a barbaric environment of tyrants fresh from the Spanish Inquisition. If you do something of which they disapprove (which I do all the time in Photoshop) there is a roar from the heavens of 'Die, heretic!' lly

It's repairable. Make that the focus of your feelings. Personally I would not regard mounting an instrument this size as a one man job. My wife is used to taking charge of the lock nuts on the saddle plate and to confirming that the dovetail is located within it. When we recently hefted a 14 inch SCT onto a GEM we had two lifters and one saddle plate clamp tightener. I had also fitted a custom handle to the front of the OTA to help the other lifter. It's a known problem: George Willis RIitchey and his assistant lost control of the first large Ritchey-Chrétien primary he had been commissioned to build and the mirror was damaged. His assistant, alas, suffered severe hand injuries. Anyway, you'll soon be back in business. Chin up. Olly

Oh, I agree entirely about the virtues of the fast, widefield system and am using one at the moment, a RASA 8. Olly

I don't understand the second part of this (ie 'compressing the image circle.') What we haven't talked about is the important issue of 'object photons.' If your object of interest will fit on the chip with and without the reducer then you get the same number of photons from the object with and without the reducer. The reducer compresses them onto fewer pixels so you get a smaller image more quickly than you would get a larger one. This is hardly a surprise! It takes my car longer to do 100 miles than to do 50 miles. I would like to point out to Starizona that its speed is not greater when it makes the shorter journey in half the time. If your 'object of interest' is everything on the wider field provided by the reducer then you will reach an acceptable S/N ratio in a time reduced in accordance with the classic F ratio rule. Olly

I think condensation is a 100% non-issue. I have a number of metal-roofed roll offs and all I do is have them lined with sheets of rigid insulation material. These are corrugated roofs so the sheets only touch where they touch but, even so, there are no drips. If there were, I'd fix the flat sheets to the corrugated metal by using expanding foam. On two of the roll-offs I've built I used alternatives to corrugated steel but that is not a mistake I will make again. If you can make the whole thing in steel then I'd do so in a heartbeat. Olly

Yes, I'm working on the names! Unfortunately this didn't occur to me till I'd built quite a bit of the gallery. I'm not sure about links, though I guess they can be placed on the site in the form of photos. Olly

The effect of focal reducers on light gathering can be stated with absolute certainty. It is zero. How can a lens at the back of the lightpath increase the amount of light going in at the front? What a focal reducer does is change the way in which the captured light is distributed onto the chip. That is all it does. What Starizona should do is stop comparing a Hyperstar with the scope it was originally, since it is now a totally different kind of scope suitable for totally different targets. They should, instead, compare it with other scopes of comparable focal length. This is what I did recently in a magazine article on the RASA 8. Its 400mm focal length is comparable with that of a fast 85mm refractor, say. The area of clear aperture is 4.5x larger for the RASA so it is 4.5 times faster at taking the same picture. This comparison is meaningful. (Note that a simple comparison of F ratios, 4.7 versus 2.0, would have made the RASA 5.5 x faster so I looked only at clear aperture.) Hyperstar stick with the meaningless '25x' faster claim up front because it is an attention grabber and I maintain that it is also a lie. Olly