This is my first ever photo (with thanks to the help of a member) and I have a question. How much post-processing is considered 'too much' to the astrophotography community?
As I was stacking in photoshop, I used one photo with extra saturation to bring out the colours and reduced the opacity to 20% as I stacked it so it helped the colour to pop. And I really love it, but as I am an amateur, I am just wondering what is the culture in terms of what is considered 'bad' or 'good'? Is this a bad photo?
Interested to hear your thoughts and if you have examples of bad or good, that would be great.
I would say it is extremely subjective as a topic. Ask ten astrophotographers that question and you will get 11 different answers. Even in my own images I have done everything from a quick integration (In tools like Astro Pixel Processor rather than Photoshop) and very minor tweaks in Photoshop as well as cropping to frame it (Literally processing an image over breakfast that was shot the night before) to a day of fiddling and never really being happy. The only person you really have to please is yourself, but your own opinion on any given image you have made will change over time.
Like most people my first image was of the Orion nebula and I would have been quite happy with what you have posted there as my first go at it.
I would say it is extremely subjective as a topic. Ask ten astrophotographers that question and you will get 11 different answers. Even in my own images I have done everything from a quick integration (In tools like Astro Pixel Processor rather than Photoshop) and very minor tweaks in Photoshop as well as cropping to frame it (Literally processing an image over breakfast that was shot the night before) to a day of fiddling and never really being happy. The only person you really have to please is yourself, but your own opinion on any given image you have made will change over time.
Like most people my first image was of the Orion nebula and I would have been quite happy with what you have posted there as my first go at it.
Thanks for your response
I do see some ordinary landscape photography being over-processed and really hate it, but deep space photography has a very different dynamic, almost like we are aware that some images are over processed and are still okay with it.
Sometimes, the way that I have seen some pictures, it is almost an artistic expression, which returns back to your subjective comment. I guess, ultimately, that is photography and I will stick to what I like. I really do like this picture as I am confident I have not over processed it, keeping the integrity as close as I could to the original but enhanced the colour and black, yet even so, there should be some explanation in terms of what this integrity of deep space imagery actually means or at least, when I spot a really over-processed image, I can immediately understand that. I don't think I yet have that skill.
How much processing you like is just the right amount.... I've seen so many images of Orion and nearly all are different and I am yet to find one that I didn't like.
I do see some ordinary landscape photography being over-processed and really hate it, but deep space photography has a very different dynamic, almost like we are aware that some images are over processed and are still okay with it.
Sometimes, the way that I have seen some pictures, it is almost an artistic expression, which returns back to your subjective comment. I guess, ultimately, that is photography and I will stick to what I like. I really do like this picture as I am confident I have not over processed it, keeping the integrity as close as I could to the original but enhanced the colour and black, yet even so, there should be some explanation in terms of what this integrity of deep space imagery actually means or at least, when I spot a really over-processed image, I can immediately understand that. I don't think I yet have that skill.
Thanks again
Talking in terms of artistic expression, that does hit the nail on the head as far as I am concerned. Unless you are doing spectroscopy or some similar, more scientific endeavour, there is always an aesthetic element to this sort of astrophotography and that is where subjective judgements come in to it.
Processing wise it is a little hard to tell with the compression of the image, but one of the things I quickly learned not to do is clip the blacks in photoshop, if the histogram is firmly attached to the left then it is likely a lot of background information is being lost by clamping it to 0. I aim for dark backgrounds to have a texture, something like a very black, new blackboard that has never had chalk on it. Basically almost black, but slightly mottled looking.
Bojan mentioned lens distortions, I was not going to comment without knowing what it was shot on. If it was a pure DSLR shot you might try stopping the lens down a little from it's fastest, often camera lenses show up that sort of thing on astro photos and it can sometimes be helped by stopping down.
I must say that getting a result like that using Photoshop impresses me, I have never had much success at all in building an image direct in photoshop and stretching it there to reveal faint stuff.
IMO, image is quite OK, but lens is a bit problematic (distortions in corners.. and I am aware your question was not about that)...
I appreciate the feedback, actually, and I am unsure why there was aberrations. I don't mind the halos around the surrounding stars, but I was frustrated at field curvature around the edges. Do you have any tips about how that can be resolved (I was unsuccessful during post-processing). The telescope is a William Optics Zenithstar 71APO and a Nikon D7500.
How much processing you like is just the right amount.... I've seen so many images of Orion and nearly all are different and I am yet to find one that I didn't like.
This was what actually sparked the thought, and you are right, I too liked all of the pictures I saw, but because they were each different, it made me concerned in some way that a more practiced eye (that I don't yet have) could tell what was a 'better' shot. I think, ultimately, a sharp and flat shot of an object is great, but how it is processed and enhanced is really a decision made by the photographer based on what they like.
Welcome! The first and only rule has to be to have fun.
For me a big part of the fun is understanding what is up there, trying to understand the physics of what I'm seeing, and trying to show something of that in the photos.
Let's give a concrete example. Let's say we've photographed a globular cluster. These things are about 10 billion years old. Most of the stars are very small and very cool, and therefore orange-red. Otherwise, they would not have lasted ten billion years. Hot blue stars last only a million years or so before exploding as a supernova. But a small number of the stars in a globular cluster have recently collided and merged, to form larger, hotter, and therefore bluer stars called "blue stragglers". So, if you show your globular cluster and you show all the stars as a beautiful blue, it should be a conscious decision to "tell a lie about what is up there", rather than just making a terrible gaffe.
Another example: Let's say we've photographed a face-on spiral. Most face-on spirals have a core of very old, orange stars, and spiral arms where new star formation is occurring. These will be reddish (from hydrogen alpha) with very strong dots and streaks of bright blue from exceedingly young, exceedingly hot and luminous OB stars which wildly dominate by being 10,000 times brighter than their friends. Then there will be black-brown dust lanes. If your photo of the galaxy is all blue, or all red, something is very wrong. You are not showing what is up there. But if you make it so that the galaxy is on average colour neutral, but make the blues a bit bluer, the reds a bit redder, the yellows a bit more yellow, that's not cheating. Exaggerate the colour differences until they are visible, but not garish. It's helping the viewer appreciate the astrophysics that is actually up there.
Unless you have at least some understanding of what it is that you are photographing, almost any manipulation in PhotoShop will be arbitrary and will lose information. Examples: clipping the darks to black loses faint detail. Clipping the brights to white burns out fine detail in shock fronts, and can convert subtle star colours to boring white. Over-zealous noise reduction will lose subtle detail and posterize the image. Over-zealous sharpening will produce all manner of hideous artifacts that are not actually up there, no matter how impressively "sharp" they might look.
So let a reasonably solid amateur understanding of what it is that you are photographing, and a desire to at least at first - until you are an expert - show what is truly up there - be your guide.
Talking in terms of artistic expression, that does hit the nail on the head as far as I am concerned. Unless you are doing spectroscopy or some similar, more scientific endeavour, there is always an aesthetic element to this sort of astrophotography and that is where subjective judgements come in to it.
Processing wise it is a little hard to tell with the compression of the image, but one of the things I quickly learned not to do is clip the blacks in photoshop, if the histogram is firmly attached to the left then it is likely a lot of background information is being lost by clamping it to 0. I aim for dark backgrounds to have a texture, something like a very black, new blackboard that has never had chalk on it. Basically almost black, but slightly mottled looking.
Bojan mentioned lens distortions, I was not going to comment without knowing what it was shot on. If it was a pure DSLR shot you might try stopping the lens down a little from it's fastest, often camera lenses show up that sort of thing on astro photos and it can sometimes be helped by stopping down.
I must say that getting a result like that using Photoshop impresses me, I have never had much success at all in building an image direct in photoshop and stretching it there to reveal faint stuff.
Thanks for your tips about blacks, I will definitely keep that in mind. I actually tried using Astro Pixel Processor and it was really frustrating for me, and then Deep Sky Stacker was playing up and I got all flustered. There is something somewhat independent about the process in photoshop that I liked, and because I actually do film and audio (so I use mostly adobe products), I felt comfortable with the process because I had so much more control over it. I actually didn't stretch this, but I can see how that would be complicated with PS.
As mentioned to Bojan, I used a Zenithstar 71APO telescope with a Nikon D7500 attached, but I must admit that the t-adapter to the t-ring was stuck on (I could not remove it) and so there was some issues related to adjusting the distance on the field flattener because of it. I am assuming this may be the cause, but I am not sure.
Let's give a concrete example. Let's say we've photographed a globular cluster. These things are about 10 billion years old. Most of the stars are very small and very cool, and therefore orange-red. Otherwise, they would not have lasted ten billion years. Hot blue stars last only a million years or so before exploding as a supernova. But a small number of the stars in a globular cluster have recently collided and merged, to form larger, hotter, and therefore bluer stars called "blue stragglers". So, if you show your globular cluster and you show all the stars as a beautiful blue, it should be a conscious decision to "tell a lie about what is up there", rather than just making a terrible gaffe.
Thanks Mike, I really love that example, and yes, understanding the elements of the celestial objects and its age, distance and brightness etc should give one a better understanding of the characteristics of the colour reflection, and this should then align with post-processing decisions. However, the equipment that you use could also potentially undermine the integrity of those elements. I think, also, it is the way that you stack in photoshop that matters, and where I use some images that may lose faint details and yet enhance the blacks, I reduce the opacity of that and layer that to an image that has those outer and fainter details, so it balances it out.
I am definitely on the same page in terms of being an amateur and the whole process of learning, which is exactly what I want to do. I think you are right, a bad astrophoto are really those who are overzealous in terms of sharpening etc.
Looking at your pic closer, I see that the coma is all pointing towards the centre, so I reckon there may be an issue with back spacing.
I have shamelessly pillaged the following image from somewhere on FB. I used it to sort out a similar issue.
If you look at the William Optics site you'll find the recommended backspacing for your Zenithstar .. work out that the distance from the flange on the camera to the sensor is ... and if that works out to be the recommended back spacing, all is good... if not you need to look at spacers or another way to get the distance right. I know the WO flatteners are adjustable to allow for this.
Looking at your pic closer, I see that the coma is all pointing towards the centre, so I reckon there may be an issue with back spacing.
I have shamelessly pillaged the following image from somewhere on FB. I used it to sort out a similar issue.
If you look at the William Optics site you'll find the recommended backspacing for your Zenithstar .. work out that the distance from the flange on the camera to the sensor is ... and if that works out to be the recommended back spacing, all is good... if not you need to look at spacers or another way to get the distance right. I know the WO flatteners are adjustable to allow for this.
Oh, that's great, thanks. I do know that the t-adapter to the t-ring was stuck on (I could not remove it) and so there was some issues related to adjusting the distance on the field flattener because of it. This now makes sense.
Spacing is quite likely to be your issue, Does it have the WO Flat6? That is supposedly set up to be at the correct 55mm distance to a standard DSLR with a T ring attached. but I always treat "Should" with a grain of salt. You have "Warp speed" stars in the corners which suggests that the spacing is too small.
APP takes a bit of getting used to but is really worthwhile for astro shots when it comes to integration of multiple shots. I assume you are shooting raw or TIF files?
