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  • Writer's pictureEmma

A Guide to Astro-Photography// PART TWO

Updated: May 27, 2020

Kia Ora!

This is the second part of my two part series on basically everything I know about astro-photography. In this post I will be covering compositions (what is in your photo), how to take the more advanced photos and also editing techniques I use. In my first post I covered what I knew about the equipment and settings within the camera, and you can find that by clicking on the image on the right if you didn't catch that!



DIFFERENT COMPOSITIONS -

When I say compositions, I mean whether it's a regular shot, a star trail or something entirely different. For example:


I added a little guide in my first post, which included the settings I used for the first image.

QUICK GUIDE - REGULAR SHOTS

- Use a Tripod!

- Manual Mode

- Manual Focus

- Aperture - As low as possible (F3,5)

- Shutter Speed - Between 20-30s depending on conditions

- ISO - Between 3200-6400 depending on conditions

- RAW file

QUICK GUIDE - STAR TRAIL SHOTS

- Use a Tripod!

- Bulb Mode

- Manual Focus

- Aperture - As low as possible (F3.5)

- Custom Time-frame depending on desired trails

- ISO - Between 100-400 depending on conditions

- RAW file

However, star trails are little different. This is where you either deliberately use the earth's rotation in your photo, or you stack a heap of exposures in post shoot editing software. If you are planning to take a long exposure photo to capture the trails in one shot, you will need to switch from Manual mode to what is called Bulb on a Canon camera. This enables you to hold and release the shutter at your own speed (instead of being limited to 30s.) Once you have this setting, it pays to have a shutter release cable, so that you don't have to use an app (and rely on your phone battery and automatic screen off setting). *cough* not speaking from experience at all *cough*. I've had multiple shots ruined from my phone attempting to talk to my camera, so if you have the money I would definitely recommend one. I'm a bit of a hypocrite as I have not used one personally as they can be expensive, but I have managed okay without it.


Once you have your camera shutting and releasing remotely at the push of a button either on your phone, laptop or through a cable/remote, you should set a time for how long you want your exposure to be. I usually go for between 20 minutes to an hour. I believe the one displayed took me an hour of sitting to shoot. So be prepared to be patient.


You should have your ISO as low as possible, as the shutter is going to be open for a while. I left the aperture at F3.5 for this shot, if I can remember it was by accident, but the lighting turned out how I wanted it so I would only recommend fiddling with ISO.


The app I recommended in my first post, 'Sky Safari' also enables you to find where the Zenith and Nadir are (the axis on which Earth rotates). In the top right of the trail shot above you can see I have the center of rotation in my photo. Planning a photo around this will determine how long your star trails are. Indicative in this photo, the further away from the center of rotation you are, the long your streaks will be.

While I am comfortable with the technique that involves one long shot, I have not tried the stacking method as the 70D model is too old, and does not have a time lapse/intervalometer built in. An intervalometer is a device that tells it to take a photo for example: every minute, at a 20s exposure. In this method, you get a bunch photos, of which you can stack and turn into similar compositions. I have heard that software such as Photoshop and StarStax can be used for this quite easily, but I'd rather not be taking a photo every minute for 2 hours in an attempt to manually do what a remote can do automatically.

Alternatively, something I came across super recently was the software built into EOS Utility, which unfortunately is only available for Canon cameras. This enables the camera to talk to a laptop and the software, in which there is a built-in intervalometer, or interval timer I believe it's called.

QUICK GUIDE - MOON SHOTS

- Use a Tripod!

- Manual Mode

- Manual Focus

- Aperture - F10-18 depending on conditions

- Shutter Speed - 1/100s depending on conditions

- ISO - 800-3200 depending on conditions

- RAW file


I used aperture F16, shutter speed 1/100s and ISO3200 for the shot above, however, I could have lowered my ISO and compensated by dropping my aperture to reduce the risk of a grainy shot. I also used a larger lens with a capability of 75-300mm, which enabled me to get the moon in a larger frame. Moon shots are pretty easy, just adjust the settings to the desired look, whether that be a lighter or darker exposure so that you can see the craters.


EDITING REGULAR PHOTOS -


My main tip for editing star photos, and to be honest, this applies to most photography is: don't over edit. Warped colours and wacky exposure vs contrast always looks a little funky. These tips below can also apply to star trail and moon photography; aim to get the colours looking vibrant enough without looking fake. My rule of thumb is that if you can look at the photo and straight-away think you've edited something, you've gone too far (at least with colour correction editing.)


I use Adobe Lightroom (mobile not classic) and occasionally Photoshop to edit my photos. I can't really say there's a particular way to edit star photos, because if I'm honest, every shoot is different. This actually makes it really hard to create presets for it, because what looks good on one photo looks really crappy on another.


When I'm editing a normal star photo the first setting I go to is usually the exposure. I up this so that the stars and galaxy are more easily seen, but not to the point where it looks pixelated because of all the fake light you have injected into the photo. Similarly, I put the contrast up, just to balance the photo out a little. However, overdoing this will give you a very dark image with colours that 'contrast' a bit too much. Some variety of light is good in the photo, it looks more natural.


Because of where I live and the light pollution, I tend to have to put my highlights slider down to balance out the harsher light, and instead use the whites slider to bring out the stars from the photo. You can also use the blacks slider to add a little more contrast, but if over-used you will lose precious colours of the galaxy. The shadows slider can actually be handy in places to add more light to the photo, but like everything else, is to be used in moderation.


Whatever you do, unless you really have to balance out some wacky tones, do NOT touch the temperature slider. It can be really tempting to get that golden hue or cool feel, but it honestly just makes the photo instantly artificial. Tint can be used slightly to adjust some tones within the galaxy, but do not get sucked into the illusion of having purple tones in your photo, it will look too doctored. Vibrance is a good slider to use to bring the colours of the galaxy out. If used too much it will make your photo look pixelated and bring out random spots of vibrant colour, which you do not want. Saturation is also good, but too much will make it look unnatural, which is against the whole point of my editing process.


In terms of the colour mixers, I sometimes up the saturation in colours like purple, pink and orange just to help give some of those photos a little more depth of colour.


I generally don't use the section below including texture, de-haze, clarity vignette and grain, however clarity used in small amounts can be good to bring everything out of the photo a little more. Split toning is great when you know how to use it well. This is not so in my case, to me using this effect always seems to cross that line of natural and artificial colour.


A setting I definitely recommend though, is the colour noise reduction, not noise reduction. This gets rid of those horrible pixelated bits that I'm assuming is picked up by having a high ISO and an edited exposure.


CREATING A COMPOSITE IMAGE -


This pretty much means stapling two images together as one.

For example:

This is honestly super easy to do once you have your head around it, although sadly is impossible to pull off in real life. Once in Photoshop, I opened my star image, which was the base photo. I then dragged the horse photo over the top. I set the horse image layer to Darken, which eliminated most of the highlights. There was also a bit of unwanted detail, which can all be erased manually. I then copied and pasted either end of the ground using the Marquee tool, and stretched it out so that I could make the horse a little smaller in the final photo. After that I filled in any gaps using the brush tool after flattening it, and that's all! Easy as!

I believe that's about all I know! There's bound to be other little things that I missed, but maybe sometime in the future I will do a refresher post. For now I hope these tips come in handy!




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