R1k

I am shooting with a Canon 800d and SW ED80. apparently the sweet spot for my DSLR is ISO200. Below are 2 single, cropped, 5 minute guided subs at ISO200 and ISO800 using a mounted L-eNhance filter.

Which is likely to stack better? The ISO800 image clearly has more signal so I feel reluctant to use ISO200 despite it being the optimum ISO for my camera

thanks in advance 

First attempt at the Pleiades after taking my first image ever in June. 

As always keen on receiving CC (I am not happy with the star field). This is 75 minutes (15 x 5 minutes) using a modified Canon 800d and SW ED80, no filter. Stacked and calibrated in APP and processed in PS CS6. 

Just to add to this, I added two panels to these images last night to create a four panel mosaic of the Cygnus Loop. I processed this with a slightly different flow (starless processing then star mask blended afterwards). I much prefer the result!

Here is my basic workflow:

- For each of the four panels, Raw files loaded, calibrated and integrated in APP using the algorithms "Ha-OIII extract Ha" and "Ha-OIII extract OIII". Autostretched images (1 x Ha and 1 x OIII) saved as 16 bit TIFF files

- For each of the four panels, Ha and OIII extracted TIFFs combined using Astronomy tools action set action - "Construct RGB image from channel files". Ha assigned to Red, OIII assigned to blue and green (HOO palette)

- Mosaic from panels created using Microsoft ICE

- Mosaic loaded In PS, manual creation of star mask in PS for later blending onto Starless image

- Starnet++ on original mosaic image to remove stars

- Curve stretch/levels in PS on starless image

- Noise reduction on starless image

- Saturation and vibrance to preference

- Blended star mask from earlier onto starless image, 90% opacity

18th and 19th September 2020

Manchester

Hi guys, these are my latest and best photographs to date. I am very new to imaging (acquired my first mount and scope in May this year and shot my first DSO in June). I am happy with the Eastern Veil Nebula but struggled with processing the Western Veil and Pickering's Triangle - in particular, I would like feedback on this photograph (struggle with star control).

Thanks

Rik

Equipment:

- Skywatcher HEQ5-pro (Rowan Belt Mod)

- Canon 800d (modded)

- Skywatcher Evostar 80ED

- Altair Lightwave 0.8x focal reducer/field flattener

- ZWO ASI-120MM-mini guide camera - SW 9x50 finderscope

- 2 inch mounted Optolong L-eNhance

Acquisition:

- Sharpcap polar alignment, ST4 autoguiding with PHD2

- Manual acquisition using intervalometer

- Lights - Western: 20 x 360s (2 hours)

- Lights - Eastern: 32 x 360 (3 hours 12 minutes)

- Darks – 20

- Bias – 30

- Flats - 30

Processing:

- Raw files loaded, calibrated and integrated in APP using the algorithms "Ha-OIII extract Ha" and "Ha-OIII extract OIII". Autostretched images (1 x Ha and 1 x OIII) saved as 16 bit TIFF files

- Ha and OIII extracted TIFFs combined using Astronomy tools action set action - "Construct RGB image from channel files". Ha assigned to Red, OIII assigned to blue and green (HOO palette)

- Crop

- Further mild stretch of data using levels/curves

- S curve to increase contrast between dark sky and DSO

· Very Aggressive star reduction using star mask and Astronomy tools action set "Make stars smaller" – I think I ran the action at least 8 times

- Colormancer plugin noise reduction

- A little sharpening using Unsharp mask in PS

- Saturation and vibrance to preference

- Watermark added

11 hours ago, Hallingskies said:

I've found that the easiest way to "process out" star haloes is to make a starless version of your finished (and presumably stretched) stack using Starnet, and then layer over an unstretched version in "Blend Lighten" mode. You may need to play around with just how much you stretch out the image before star removal, as sometimes the larger haloes can get left behind, but once the stars are out of the way you can really go for it on processing nebulae if you want.

However, I've also found that I quite like a little bit of halation - it makes an image look more natural.  I think your image above looks great and the star haloes enhance the view, rather than detract from it.  Each to their own, though...

Thanks for this, will give it a shot! Appreciate the feedback

Hi guys, I hope that you might be able to help. I have recently got to grips (or so I think) with creating star masks in PS with the intention of stretching my DSO independent of the stars. Although I have been partly successful in this task, I have been unable to devise a means of minimising halos around the stars when doing this. I am using the technique described here 

I have uploaded on of my processed images (North America Nebula) which I hope will provide a visual representation of my issue 

many thanks for your help

On 20/08/2020 at 22:50, Adam J said:

oh and should have said, clearly lens cap off

On 20/08/2020 at 22:24, John said:

It looks like some fluid between the lens elements ?

 

Hi guys, just wanted to say thanks - all cleared up after about 5 days of being kept dry and with the dew heater on for most of it. Appreciate the help

8 minutes ago, Adam J said:

If it will not shift after a week or so then remove the lens cell as above and put it into a sealed bag with some dessicant.

Until then keep the scope in a well ventilated area out of its box. Dont try and do anything like putting it on a radiator or heating it for an extended period with a hair dryer.

Adam

Thanks, will monitor and then try this. Cheers 

Fluid/water potentially makes sense, got caught unexpected in rain a few days back for a short period... All the other moisture has now gone, just this area remaining, I’m surprised if it is water as it does not change shape no matter how much I change the position of scope etc.  I can’t say for sure that it’s new.

Can anybody tell me what this imperfection is on the rear lens of my doublet Evostar 80ED? Is the coating peeled off? 
 

 It does not shift on rotating the scope or any positional change for that matter.

thanks in advance

On 03/08/2020 at 13:53, tomato said:

That's a great M31. I note you calibrated and stacked in DSS then moved to APP for onward processing. I'm not knocking DSS but please have a look  at calibrating and stacking in APP, quite a few more options than DSS but the auto settings on the latest version work really well. Its a shame not to use it if you have access to it, it's fine  reputation to date has been built primarily on it's calibration and stacking capabilities.

Had a quick go and calibrating and stacking in APP then finished off again in PS. Was a fairly similar result. Did mess with the colour balance but here it is. Thanks for the advice, it’s appreciated

1 hour ago, PeterCPC said:

According to the Altair site - The base of the 2" OD barrel is threaded for 2" filters.

Peter

Thanks Peter, I should’ve checked there! Appreciate you taking the time to check and reply.

Hi guys, I’m looking to buy an Optolong L-eNhance duo NB filter for use with my setup (canon 800d Modded - Altair lightwave reducer - focuser - SW ED80).

Id prefer to purchase a 2 inch mounted filter rather than an EOS clip in one but I’m unsure as to where it fits in the imaging train. I know that people with WO reducers can thread it to the inside of the flattener (the side that enters the focuser).

Does anyone know if this is possible with the Altair lightwave reducer? It is threadded on the inside (pictured)

thanks! 

Thanks Michael, that makes a whole lot more sense, appreciate the time you’ve taken to explain this. I will look to add more data to this image in the coming days/weeks at a lower ISO and will update the thread. Will also have a go at stacking in APP. Thanks again

19 hours ago, michael.h.f.wilkinson said:

Very nice indeed. The background is still a bit noisy, but that is to be expected. As ever, adding more data should improve that. You could also consider going to a lower ISO value. I have an EOS 80D which has a similar sensor, and I find I tend to get best results at ISO 200. For the older modded 550D I tend to go for ISO 800, but the more modern cameras get better dynamic range at lower ISO values, so less chance of blowing out stars or the cores of bright nebulae

Thanks michael, I’m still limited by exposure duration as I’m not guiding, would it still be worth going for a lower ISO in this case? I’m not quite familiar with the theory of dynamic range 

Incredible job! What is your guiding setup?

Thanks for the very kind comments. I will look to add more data to this in the coming weeks. Appreciate the support

This is my 4th DSO after starting in the hobby in June. This attempt is my best to date. More than happy to receive feedback. Process and equipment below:

North West UK

1/8/20, 02.30am

Bortle 6 skies

Equipment:

- Canon 800d unmodified

- Skywatcher Evostar 80ED

- Altair lightwave 0.8x field flattener

- Rowan belt modded SW HEQ5-pro

Acquisition:

- No guiding, no acquisition software, manual polar alignment

- Lights: 34 x 90 second exposures (total integration 51 minutes), ISO 800

- Darks: 20

- Bias: 20

- Flats: 20

Processing:

- Stacked sub-exposures in DSS

- Loaded stacked TIFF in Astro Pixel Processor - autostretch, crop, rotate 180 degrees (preference), removed light pollution, saved file as TIFF

- Loaded APP processed TIFF in PS - set black point, adjust levels to achieve correct colour balance, lasso galaxy and select inverse, gradient Xterminator, very slight further stretch, from Astronomy tools action set - "make stars smaller" x 4, local contrast enhancement, "make stars smaller" x 2,  adjust vibrance/saturation, denoise using Colormancer noise reduction plugin for PS

Quick newbie question - where would the 2 inch filter fit in your imaging train? Assuming DSLR - field flattener - scope

thanks

RGB* not RBG, sorry.

Hi guys, I have 71 minutes  captured using an unmodified Canon 800dDSLR (71 x 60s) on M51 (20 darks, 30 bias, 30 flats) - this is my first DSO image with a refractor scope (Evostar 80ED), I had previously been using a 300mm cheap canon lens on my HEQ5. I have done my best to process in PS CS6 this after stacking in DSS. My workflow is mega basic at the moment and effectively just involves stretch, saturation, gradient removal and denoise. My processing effort for this object is shown below! 

I would like some feedback on the processing side of things and would be keen for others to have a bash at the data (TIF attached) so that I can get an idea of how much extra can be achieved with the data I obtained. 

Many thanks, and clear skies!

Autosave.tif

16 minutes ago, Kyle Allen said:

I think you've done really well to capture what you have with the standard kit lens in such a short amount of time. I had a go at stretching the TIF file you linked to in GIMP. I'm relatively new to astrophotography myself so my image processing skills need some work - I haven't had the chance to capture much of my own data so I appreciate you making yours available for me to practice on! 😀

Taking flats would definitely help to remove the vignetting. The corners are a lot darker than the centre even after cropping it a lot. I normally take about 15 of them and it seems to work well.

Other than that, just stacking more exposures should help. I don't think you can take too many of them!

Here's what I managed...

.

4 minutes ago, Cuto100200 said:

Ahh understood that's really cool, I still need to learn how to do darks and bias's. When finding an object in the sky, do you just aim the camera at it and shoot or do you zoom or crop somehow to get it enlarged? 

my mount is GoTo so it will find the object for me, the image I posted is only a little cropped. I have uploaded the uncropped version below. The effective focal length is 300mm x 1.6 (as I am using a crop sensor camera).

6 minutes ago, Cuto100200 said:

This is very cool, how would you go about doing this? Do you just take many long exposures and then stack them or do you have a tracker?

Sorry I should have qualified this. This is a Canon 800d with the aforementioned lens mounted on a SW HEQ5pro. No guiding, no capture software. Just the camera, lens and mount. Intervalometer used to capture exposures (26 x 90s lights, 15 darks, 60 bias, no flats). Stacked in DSS and  processed in PS CS6