Photosbykev

Good morning folks,

I've been shooting with a stock 5D MkIV attached to the back of a WOZ61 with Flat61A flattener and IDAS-D2 filter. Very pleased with the results I'm getting but I have a spare Canon 5D MkIII which i want to get modified to grab more Ha.

Bearing in mind I would like to use the modded camera with standard DLSR prime lenses as well is the best modification just to remove the UV/IR and Colour correction filter on the sensor leaving the AntiAliasing/UV/IR cut filter in place or remove both and replace with a clear glass filter? I suspect the standard Canon AA/UV/IR filter cutoff is a bit too close to the Ha band so I will lose some Ha data if the AA/UV/IR cut filter is left in place?

If I go down the clear glass filter route I think this means I would need to use a UV/IR filter when shooting with the standard DSLR lenses to avoid bloating and focus problems.

Are there any negatives if I leave the AA/UV/IR cut filter on the sensor for astrophotography with the refractor or with standard DSLR lenses or should I just get the full spectrum modification and then install a Astronomik CLS CCD XL clip-in filter into the 5D3 body and remove the IDAS-D2 filter from the refractor?

best regards

Kev

I've updated the processing on the Veil and used StarNet to remove all of the star field before reprocessing the nebula and adding the star field back into the final image

A revisit to the Veil nebula using a stock Canon 5D4 and WO Zenithstar 61 with Flat61A flattener and IDAS-D2 filter on a SkyGuider PRo mount guiding with a ZWO ASI120mm and 30mm f/4 guidescope. Plenty of dithering between lights  Moon at 80% wasn't helping but it gives me some idea of what is achievable without going down the modified camera route.

40 x 4 minutes lights 20 x flats/darks and 50 bias frames. Calibrated and aligned in Astro Pixel Processor and then finished in PixInsight

6 hours ago, wxsatuser said:

I suppose it's not the mirror when its up, it might just get in the light path.

I had a similar thing on the 6D with a Astronomik lp filter in place it just left a band
 but if I remeber right it was'nt coloured.

I would be very surprised if it was. The IDAS-D2 filter is inside the Flat61A flattener so in theory the mirror should be well clear of the optical path. It certainly isn't visible in any flat images

3 hours ago, wxsatuser said:

You don't need to remove these unless the plane ones are really close.
Correct stacking and more than 12 subs will get rid of any satellites and most planes.

Thank you FWIW I shot the Veil last night 40x4min subs and the cyan banding was still present in all the subs. Plenty of detail for a stock Canon 5D4 but the banding is strange

Kev

1 hour ago, michael8554 said:

Glad you got it sorted. 

Just for reference, by sources I meant stacking sources - lights, flats, Bias etc, not Leads. 

Michael 

Well I seriously misread that piece of advice lol.

I use blink in PI to scan every image and then remove any with satellites/planes in them and also any image with distorted stars (touch wood I don't get many of those). I shoot flats for every session so I don't think the issue is there. I think I'm having finger trouble in selecting options during calibration/registration of the data which I need to figure out. 

Currently shooting 3 hours of subs on the Veil with all the cabling reconfigured so I'll have some fresh data to test with. 

Kev

I finally sorted out the bias issue, it was being subtracted twice! and below is the final image from 20 x lights/flats/darks and 50 bias images at iso 800 4 minute exposures. More exposure time, subs and a new moon required to really pull the detail out.

Image calibration details were:
Center (RA, Dec):    (10.519, 41.372)
Center (RA, hms):    00h 42m 04.521s
Center (Dec, dms):    +41° 22' 17.713"
Size:    5.43 x 3.63 deg
Radius:    3.265 deg
Pixel scale:    9.54 arcsec/pixel

The final image has a minor crop of around 50-100 pixels around the border to remove the dithering artifacts but I'm really pleased with the corner stars on a full frame camera.

2 hours ago, alacant said:

Hi

Not sure what this is. Is it the bias that is causing the banding?

Are you sure it's not simply artefacts left after aligning the frames during stacking? Leaving edge aretefacts -particularly as you dithered- before stretching may produce the type of localised banding along one edge.

HTH.

Im pretty sure the banding is related to the camera, maybe cabling interference as I can just make out the banding on each 4 minute sub without aligning/stacking. I'll have a session tonight with all the cables repositioned and see if it's still visible. 

The poor bias subtraction along the bottom edge is, I think, an error in calibrating the images but I mnot sure where I'm introducing the error yet. 

Kev

1 hour ago, michael8554 said:

The band looks electronic in source. 

Go through all your sources looking for one with a fault. 

Michael 

I'm separating out all my camera leads tonight lol

2 hours ago, david_taurus83 said:

I have to say that's an impressive flat field for such a small scope and a full size sensor!

The dither movement looks fine. You need quiet a sizeable movement with a DSLR. Try stacking only the lights, bias and flats. Dithering can sometimes do away with the need for darks.

 

Also, try cropping out that bottom stacking artefact, run DBE and then try the Canon banding script.

Following up on this comment. I stacked and integrated light/flats/bias frames (excluding darks) in APP. In PI I cropped the bottom to remove the nasty bias edge, I guess I'm doing something wrong there, maybe removing the bias twice? I need to read up on this but not using the darks doesn't appear to have a significant impact at all, I guess dithering does work

I ran DBE to remove the minor vignetting and then the Canon banding removal script followed by Photometric colour correction. The image below is a result of just a simple stretch transfer function resized down to 2048 pixels wide.

Kev

1 hour ago, david_taurus83 said:

I have to say that's an impressive flat field for such a small scope and a full size sensor!

The dither movement looks fine. You need quiet a sizeable movement with a DSLR. Try stacking only the lights, bias and flats. Dithering can sometimes do away with the need for darks.

 

Also, try cropping out that bottom stacking artefact, run DBE and then try the Canon banding script.

I'm very very impressed with the 5D4 and WOZ61 and flattener, it seems to be a well matched combination.

I'll play with the restacking options and then DBE and the banding script but I would like to remove the source of the banding rather than remove it in post

Kev

1 hour ago, rockinrome said:

Could it be an internal reflection? Long shot I know, but do you cover the camera eyepiece with the rubber *thingy* that should be on the camera strap....?

All the best.
MJ
 

I didn't MJ, it's not something I've ever done and I was in a dark location so not much to reflect tbh

Good morning folks,

I was shooting M31 on Tuesday evening just to test some dithering settings with my setup (stock Canon 5D MkIV and WO Zenithstar 61 with flattener on a SkyGuider Pro mount shot through an IDAS-D2 filter) Not a perfect evening with the 85% moon coming up during the short test but good enough for what I wanted to do.

The image below is from 20 x 240s lights, 20 flats, 20 darks and 50 bias frames batch preprocessed in PixInsight and then a simple stretch transfer function to pull up the detail. The image is uncropped, full frame and just resized down to 2048px wide.

There is clearly an issue with the bias removal but more significantly there is a horizontal cyan band along the bottom which I've never come across before.

I've also included a short video (if it plays) showing the Ra dithering movement over the twenty lights which I suspect is too much movement but I can sort that.

Any help with the bias and cyan band would be appreciated.

best regards

Kev

A revised version using the same data which is much much cleaner and contains real data rather than mush  Stacked/integrated in AstroPixel Processor and PI used for the main processing. 

Stacking and integrating all the data files in PI gave some strange artifacts but APP seemed to handle the data without any issues. I can't believe how bad that first processing attempt is lol

23 minutes ago, Xplode said:

Looks very unnatural due to the hard editing.
If you use Pixinsight there's no reason to use DSS for stacking, PI does a much better job at aligning/stacking.
How does a single image look like straight from the camera?

I've just added one above from the session. I haven't got into PI stacking/integrating yet, one of my next jobs. It is heavily stretched to pull detail out, realistically if I'd got the 40 x 240 second lights the processing would have been much less severe. I'm just pleased to see how the WO Z61 with the Flat61A behaved with the full frame camera

The Veil nebula from last night using a stock Canon 5D4 with a WO Z61 scope and IDAS-D2 2" filter on a Skyguider Pro mount. I was after 40 x 240 second exposures but I got 14 before the clouds arrived.

This is 12 lights and 20 x flats/darks/bias frames stacked and aligned in DSS and processed in PI. Final image cropped 5%.

A lot more exposure required to do the region justice but I'm pleased with the performance of the scope on the portable mount

This is a single raw file converted to jpg and resized, zero processing

13 hours ago, 5haan_A said:

What kind of tweaks were these? 

 

 

FRom memory it gave me a new Minimum Move (pixels) of 0.36 rather than the default and also calculated the backlash of the drive. I didn't apply the backlash correction, not sure why not, but it made sense not to when I was playing with the numbers

I used the built in 'guiding assistant' wizard to fine tune my guiding. It suggested a few minor parameter tweaks that certainly improved the guiding for me

I've just fitted a 2" IDAS-D2 filter into the William Optics Flat61a flattener following on-line instructions.

It strikes me as odd that the filter is installed with the front of the filter facing the camera sensor rather than the 'sky', I'm assuming this is correct and shouldn't cause any reflection issues?

For info, I've attached a couple of daylight images of the filter in 'action' on a colour calibration chart showing the natural colour cast

The image above, without the filter fitted, is colour profiled in LR and white balanced using the middle grey colour patch

The image above, with the filter fitted, uses the colour profile of the first image and the white balance is also from the first image

The last image below was colour balanced using the middle grey colour patch in LR and clearly failed lol Assessing the grey colour patch there is no red in it at all so obviously the calibration would fail. It will be interesting to see it working under normal conditions photographing the night sky

Final version from the data I have using a stock Canon 5D4 camera. If anyone fancies a play with the linear Fits image file they are more than welcome if you post your results back into the thread . I think a modded DSLR or OSC cmos camera is rapidly heading towards my wishlist lol

Nice trail spoilt by that blurred thingy in the background

Lots of mistake through lack of scope time, I've seen better but I've also seen worse lol

Canon 5D4 on a WO Z61 scope mounted on a SkyGuider Pro

40 x 120 second exposures at iso800 with 30 x flats/darks/bias frames

Center (RA, Dec):    (312.966, 30.924)
Center (RA, hms):    20h 51m 51.823s
Center (Dec, dms):  +30° 55' 25.026"
Size:                        4.69 x 3.28 deg
Radius:                   2.862 deg
Pixel scale:              8.24 arcsec/pixel
Orientation:           Up is 296 degrees E of N

If nothing else I've got a few hours of data to practise with until my IDAS D2 filter arrives 

Kev

13 minutes ago, Radders said:

Wow 0.5! That is good. I think tonight is the night it's finally all come together. I'm currently shouting M31 at 3 min subs with no trailing hurrah! PHD2 is currently showing 1.34. Can live with that. 

Look forward to seeing your results. 

I ran out of battery lol I wasnt expecting to go for so long but Ive got 30 x 30s, 30 x 60s, 30 x 120s and a handful of 240s lights to play with. Battery swopped out and gonna leave the camera shooting darks for a few hours.

Kev

17 hours ago, Radders said:

Very interested in this. I have the same setup but on a Skywatcher Star Adventurer. I had no end of trouble last night. Couldn't get my guidescope scope focused until late, star trailing even on short exposures. Going to give it another go tonight as next 2 nights are forecast clear. 

 

How are you setup? I seem to be struggling still. Balance seems ok, and once I've Polar Aligned in Polemaster all is good but once I choose a target and start guiding, it all goes down hill. 

I've got a guidescope mounted alongside the wo z61 scope and camera and the balance is fractional camera heavy, not by much but enough to keep the gears engaged. Guidescope is controlled by phd2 with mount selected as on camera. Once polar aligned and tracking I'm seeing rms errors of <0.5px. At the moment I'm shooting 4min lights with no visible trailing with a full frame Canon 5D4 

8 hours ago, Radders said:

Very interested in this. I have the same setup but on a Skywatcher Star Adventurer. I had no end of trouble last night. Couldn't get my guidescope scope focused until late, star trailing even on short exposures. Going to give it another go tonight as next 2 nights are forecast clear. 

Im comfortably getting 3 minutes without any trailing with the 360mm fl scope. Tomorrow night looks good so hopefully I'll get some decent data to play with. I've also ordered an idas d2 lp filter to counter some local pollution. 

Kev