Nigel G

7 hours ago, michael8554 said:

Good thought Louise, but I think there would be a hotspot on his Darks, which there doesn't appear to be.

Nigel, have you been into the menus and turned off all the custom settings?

Michael 

There's thousands of hot pixels in the darks when I  stretched it in digital photo professional. But the bands are not oddly. The bands only appear when Picasa auto stretched it, but no hotspot.

I'm pretty sure all the custom settings are off. I will check today. 

@Thalestris24 Louise to be honest if the camera is on its last legs so be it ☺ it's just a camera. I wouldn't be surprised after the abuse it has been through in the last 2 years, stripped down 3 times, blown up once by miss aligned wires ☺

Cheers 

Nige 

Interestingly I added some dark frames with a positive result. Exactly the same subs and stacking parameters, second with darks, Both are gradient wiped and first stretch nothing else.

I really thought darks would not touch banding but here is the proof.

Nige.

Looks like the sensible thing to do is upgrade camera.

I have thought a lot about cameras and what to get.

I love the idea of a mono but would it be a good choice with so few clear nights to gather data, would a OSC be the wise choice.

I'm going to tackle this by reducing the exposure times and will try darks as it will do no harm. in fact I could add some darks to the data I have, I know its not ideal but I would see a difference to banding if it made a difference.

Nige.

Just now, tooth_dr said:

Well what’s the verdict

Ok. these are RAW opened in picasa photo viewer and screen grab cropped in paint no stretching as picasa does a small auto stretch.

Results are not what I was hoping for. All taken with lens cap on. 15 min ISO800. 

1st, straight to SD card, no wires anywhere near. 2nd, To PC avoiding all power cables. 3rd, 12V & 240V power cables everywhere crossing and running alongside USB cable.

Clearly banding in all 3, 

I would say direct to card is worse and the other 2 about even.

Now this is a dark frame showing the banding, will this not work to remove the problem used as a dark frame ?

I have read that darks will not remove banding so never bothered to use them as I dither instead.

2 minutes ago, carastro said:

I am inclined to agree with Olly, but in the meantime, here is a tip I was given some years ago:

Do you keep your SD card in the camera when you download to the laptop? 

I was told that removal of the SD card reduces this problem because something electronic (which I don't understand) can happen in the download due to the SD card being in place.  Anyway, I removed my SD card and it greatly improved/got rid of the horizontal banding problem.  This was some years ago, so I can't remember all the details 100%.

Might be worth a try though, and as stated previously try not to let power cables touch USB cables.

Carole 

I remove the SD card  actually it has only been put in for this test. 

I have taken a 15min saved to card, no connections, a 15 min with wires everywhere 12v & 240v crossing and running alongside, and the final one still going, usb to pc, avoiding all wires.

19 minutes ago, davew said:

Just a thought here Nigel but why are you waiting to waste a clear night ? Can't these experiments be done any old night ?

In fact, I would have thought you could just cap the scope and do it practically any time so long as the temperature isn't too high.

Good luck with it,

Dave.

Very true, I'm on to it now, a couple of tests, 

1 save straight to card,  not connected to the PC maybe camera in the fridge for this one.

2 save to PC via USB no power cable nearby. 

Cheers 

Nige 

1 hour ago, tooth_dr said:

Hopefully it’ll be clear with you tonight!

Forecast partly clear, so its possible  

6 hours ago, michael8554 said:

Take some Images with a camera battery installed.

Michael 

Hi Michael,  I  only ever use batteries in my camera, it's the mount power cable potentially causing the problem.  ☺

Cheers 

Nige 

I'm thinking mainly electrical interference but also getting close to what my 1200D is capable of.

A combination of things. 

We shall hopefully find out next clear night.

I could do a long exposure test in the shed tonight. no power cable nearby.

11 minutes ago, michaelmorris said:

I would have thought that 15-30 minute exposures is going to be really pushing the limits of DSLR astrophotography and as a result I'm not surprised that you're getting banding.  I know it is not ideal, but would have thought that taking more, shorter, exposures might help.

Very good point  

I do tend to try and find the limits of my equipment.

Also getting fewer subs to stack with longer exposures which wouldn't help.

5 minutes ago, michaelmorris said:

My understanding is that banding is likely to get worse the more you stretch an image.  If your tracking and /or guiding is spot on, stacking subs will just increase the problem.  One way around this is to dither between each sub.  

Dithering is moving the mount by a small random distance between each sub-exposure (just a few pixels).  Therefore whilst the fixed pattern noise stays in the same place on each sub-exposure, the stars are in slightly different places on each image. When you come to stack these sub-exposures the stacking software aligns each image on the stars.  When these are stacked the stars are nice and sharp, but the fixed pattern noise tends to get smeared as it is offset between each aligned image.  The nett result is that all forms of fixed pattern noise (including dark or hot pixels) tend to disappear more into the background, allowing you to stretch the final image more.

http://dslr-astrophotography.com/dithering-optimal-results-dslr-astrophotography/

APT image capture software has some great dithering tools including integration with PHD guiding software and dithering when not autoguiding.

https://ideiki.com/astro/Default.aspx

I hope this helps

 

Thanks Michael.

I do dither between each sub at least 10 pixels and very random, a lot vertically, which helps and almost did rid the problem certainly reduced the banding until this one and a few before, as I'm now exposing for 15 -30 minutes with N/B filters its becoming very obvious but got extreme after running all the cables through the window.

When I last imaged Andromeda I had to do a meridian flip which helped loads as well as dithering.

I'm not sure if you can dither to much ?

Cheers

Nige.

1 hour ago, tooth_dr said:

 

Ive used four Canons avd never seen this except when above issue arose. Is it specific to 1200d?

I get banding but not so obvious with my unmodified 1300D. 

6 minutes ago, ronin said:

 

One sort of option is that the internal software is just trying to boost the level to get the G and B row of pixels up but it will do some to the R so possibly making the banding worse. What is the result without any NB filters, just simple OSC use ?

 

The banding has been a problem since I could take longer than 2 minute sub's. before I modified it and without filters makes no difference. The longer the exposure the more banding it seems.

I'm kinda thinking the electrical interference could be the main issue as it all adds up.

Only one way to find out.  

Cheers.

Nige.

2 minutes ago, Starflyer said:

I've seen this in the past in various canon cameras, IMO it's temperature related, try checking the internal camera temp in the EXIF data for subs where it's better and where it's worse.

The more you stretch the data the more the banding shows, so for the shorter exposures it may look worse because you're having to stretch it harder.

I ended up cooling my 450D and at EXIF temps below 9 or 10C the banding completely disappeared.

Cheers

Ian

 

Thanks Ian.

The last session outside temp was well below 0. The banding has been better in summer conditions 20 degree heat.

But a very valid point, I have never known how to check the sensor temp, I use Canon EOS utility to capture and never found a temp reading on that or the camera, excuse my ignorance but I'm not sure what EXIF data is  

Cheers

Nige.

25 minutes ago, tooth_dr said:

Daft question probably but could there be a power cable near the USB cable, or are you using a usb hub? I only ask because I got banding with my Canon when I ran the usb cable beside (in same duct as) the 12v power cable.

Ive used four Canons avd never seen this except when above issue arose. Is it specific to 1200d?

Thanks for your reply and very interesting.

I run my cables loose to the equipment from my conservatory, they all run out the door together, camera USB, guide cam USB and mains to 12v converter which sits next to the 2 USB cables.

Now the interesting thing is and I hadn't thought about it, the banding probably got worse after I started using mains power instead of my 12 power pack a few months ago.

This last image was a new way, we have a new 18 y old cat so can't keep the doors open yet so I ran the cables out of a window together.

You might have hit the nail on the head  

Thanks  can't wait for the next clear spell, I will try by separating the power cable completely.

I will let you know the results  

Nige.  

I have noticed my banding problem getting worse.

Its causing problems, there's good software to tackle it but now its getting worse its still visible after all the tricks I have learnt.

I have been using N/B filters and longer exposures for a couple of months.

My last session is the worst and only 600s exposures when I have been using upto 30 minute exposures with less banding.

Question.. Should the banding get worse over time and use, I'm guessing its to do with the sensor.

My Camera is a self modified 1200D, If I get the colour bayer array removed would this help ?

Or am I in desperate need of a new camera.

A sample below, 21 x 600s ISO800 12nm Ha clip filter, dithered. Gradient wiped and stretched to show the banding, and a worked on image. Detail is getting lost in trying to reduce the bands.

Any advise is greatly appreciated.

I have tried StarTools banding, PS add on's, PI trial and canon digital photo pro. Each has its improvements but non can completely resolve the problem yet.

Cheers

Nige.

On 27/12/2017 at 14:24, jjosefsen said:

Could some of you, using PHD2 for guiding, post some of your settings and what RMS values you get?

Im trying to get a sense of what I should aim for with my settings and resulting guide graph.

While my subs currently look pretty darn good (compared to unguided), I do have pretty heavy fluctuations in the graph.

Included us a couple of guidelog graphs, would appreciate if anyone had some tips on improving EQ3 guiding.

I have done the whole strip, clean and regrease on the RA axis - haven't done the DEC yet.

 

Thanks

 

Here's a good night with PHD2, 30 minute exposures going on.

The PC date is way off as this is my imaging PC and is not connected to the internet and no internal battery  

I don't really know much about the settings, the first lot I entered has work well so I don't change anything but some of them are at the bottom of the screen 

Nige.

8 hours ago, jjosefsen said:

@JemC

Thanks, looks good. Unfortunately I don't have PS, only PixInsight.

 

Photoshop CS2 is a free download and excepts all plug ins , handy to have ☺

I have had a go at the Heart nebula in bi colour. Taking 6x15 minutes Ha and 6x20 minutes OIII. Not enough but not a lot of clear sky at the moment.

First I tried opening Ha as red and OIII as blue but didn't get what I was expecting, some good detail but not the colour I was hoping for.

So I tried the Ha & OIII blend to create a fake SII and opened....Ha as lum, SII as red, Ha as green & OIII as blue. Its more like what I was looking for but the heavy processing has taken its toll on the detail. More data needed as usual. There's a lot of colour in the image and colour variations are just a matter of changing the % ratio. I need to work on this but its a start and there's no red which makes a nice change  

Modified Canon 1200D, Astronomik 12nm Ha & 12nm OIII. 80ED EQ3 pro

DSS, PHD2 & StarTools.

Cheers

Nige.

1 hour ago, pushrod said:

Hi Peter, Newbie on this forum but have been messing with AP for a year or two and was interestingly reading this thread as i image with an EQ3 synscan when i came upon your image - and thought how similar it is to my recent attempt but from a totally different approach. Recently i have given up on stacking images and just gone for single long exposures - this is a  SINGLE 407s exposure, 130 pds scope with CC through a modded dslr with a cls ccd clip filter fitted, guided with phd, and then about 30seconds worth of tweeking of the raw image in an old adobe elements. I got a bit fed up trying to learn pixinsight(trial) and gimp as i'm not the quickest learner on a computer!

I would be very interested to hear what people think of my attempt - criticism gladly accepted

A very good single exposure, nice and clean. 

20 or 30 of these stacked would make a great image. There's plenty of help in Stargazers lounge to guide you, just ask and help will come.

Nige.

10 hours ago, Thalestris24 said:

Thanks! Sounds promising, though you have to bear in mind I'm a little old lady! I'm not very strong... But I'm desperate to get outside to do some imaging instead of having to put up with the indoor limitations. It only has to run for a couple of hours (after that I'd probably need to get back in! Haha). I wonder what it's unguided performance might be like? If I could run it unguided (no laptop) with a 200mm or possibly a 300mm lens, that would be good. I guess you run it with eqmod (like I do my heq5)?

Louise

Louise, I don't use eqmod, I use in camera guiding, the old way  The guide cam is connected st4 to the handset and data cable to the PC then good old PHD2 does the hard work.

I have not used mine unguided but other users here say 2 minutes seems a good keep rate.

With the mount on the tripod and the tripod closed I would say its portable.

I would say it needs re greasing twice a year to keep it smooth though in my opinion. 

Nige.

1 hour ago, jjosefsen said:

Did a some processing on my little stack of the double cluster, 6x3mins at ISO 200.

This was my first go with guiding, and after spending most of the night getting everything working I had a little time to try and grab some light on this beatiful pair of globulars.

All in all it was a great night where I conquered a lot of the gear troubles I have been having lately.

• Polar Align with SharpCap - What a breeze it is to get good PA now!
• Guiding with PHD2 - Fairly easy to get working if im honest, but im sure it can be improved massively yet.
• Dithering with Backyard Nikon and PHD2 - Not 100% sure my settings are correct, but I think I'm aiming for a 15px dither.

Before I had about a 60% retention rate on 45sec subs (and they weren't great!), now I have 100% retention rate on the 4min subs I am taking of M33 as I type this.

Guiding certainly solves a lot of problems! I love it!

Thats a cracking double cluster, well done.

8 minutes ago, Thalestris24 said:

Hi eq3 users

I'm tempted to get an eq3-pro - might be better than messing about with a Star Adventurer... I'm wondering how portable the eq3 pro synscan is, how much power it needs, and computer interface (I assume via the handset?).  At the end of the day I just want something I can carry down two flights of stairs without breaking anything!

Thanks for any info!

Louise

Hi Louise. 

I can easy carry the mount and tripod with 1 hand, also I have a small 17 ah battery pack which so far has lasted 6 or 7 hours ( not had it run out yet )

Interface is via the handset, I use ST4 to link to my guide cam to the PC.

Hope this is helpful.

Nige.

@rotatux 

Here's a 60-40 mix  

Quite a nice blend of colours. maybe needs a bit more red in the yellow.

I still haven't done a red green trial yet.

Nige.

Something a bit different.

Here's a selection of Orions all from the same data. 2h 20m of 600s OIII filter, 1h 40m of 600s Ha filter. ISO 800.

Modified 1200D, 80ED, EQ3.

All processing in StarTools.

1 - Opened in LRGB - Ha Red 50%. OIII blue 50%

2 - Opened in LRGB. Ha Red 33%. OIII Blue 66%.

3 - Both fits stacked in DSS for a combined fits.

4 - Both opened as RGB then layered in ST.

Cheers

Nige.