DSLR Archives - Infrared Conversions, IR Modifications & Photography Tutorials

Mirrorless vs. DSLR – Which Should You Buy?

If I were writing this article a few years ago, there wouldn’t really be any competition between high-end DSLR cameras and mirrorless cameras. DSLR cameras were so far ahead that buying a mirrorless would mean compromising on several factors including image size and quality. There was also the issue around the optical viewfinder versus a digital one in a mirrorless camera (more on this later). But these days the story is very different. So which should you buy? Our guide will help you decide.

What is a DSLR camera?

Before we talk about which is the right camera for you, it’s important to understand the differences between DSLRs and mirrorless cameras. A DSLR camera is a digital single-lens reflex camera. The way in which a DSLR works is that light enters the camera and reflects into the optical viewfinder via a mirror inside the camera body. So when you look through the viewfinder, you are seeing a real-life view of the scene in front of the camera. In other words, an actual reflection (this is the main difference between a DSLR and a mirrorless camera). Then when you press the shutter release button to take a photo, the mirror flips up which allows the light to hit the camera’s sensor and create the image.

When the mirror swings up, your view in the optical viewfinder goes dark momentarily until the mirror flips down again. The benefits of having a mirror in the camera are that you get to see an actual real-life view of the scene. It also gives an extra layer of protection for your sensor against dust and debris.

What is a mirrorless camera?

A mirrorless camera works in exactly the same way as a DSLR in that light enters the camera and creates an image by hitting the camera’s sensor. But the major difference between mirrorless cameras and DSLRs is the lack of a mirror in the former. Because there is no mirror you can’t see a reflection of the scene in front of you. So, what you see instead is a digital version of the scene. This is why a mirrorless camera viewfinder is known as a “digital viewfinder”. In essence, it is the same as if you were looking at the LCD screen on the back of your DSLR in “live view” mode.

What’s the big deal about a mirror?

You may be thinking what the whole point of a mirrorless camera is if it simply lacks the mirror of a DSLR. Well, there are a few big advantages to having no mirror in a camera. For one, because there is no mirror, the camera body can be smaller and lighter in weight than a high-end DSLR. But also from a photography point of view, without the need for a mirror to have to mechanically flip-up, mirrorless cameras allow for far more frames per second than DSLRs. In fact, DSLR cameras are no longer able to compete with high-end mirrorless cameras on that front.

Optical vs. digital viewfinder

The biggest impact of a lack of mirror to a photographer is what they see in the viewfinder. As mentioned above, without a mirror you will see a digital version of the scene in front of the camera. Again, a few years ago this was one of the biggest drawbacks of mirrorless cameras as there was a slight lag between what was happening in front of the camera and what the photographer was seeing in the viewfinder. So, for example for a wildlife or sports photographer, this would be hugely detrimental as it might mean missing the perfect moment with even a minute delay. However, the recent years this has pretty much been eliminated from top of the range mirrorless cameras. Having said that, sport and wildlife photographers still do prefer the optical viewfinders of DSLRs.

So, which should I buy?

As a Canon DSLR shooter myself, it is getting increasingly more difficult to see the benefits of DSLR cameras over mirrorless. DLSRs are bigger, heavier and in most instances more expensive than an equivalent quality DSLR. Personally, I still do prefer the optical viewfinder of DSLRs but that is just because it is something that I’m used to. At the moment mirrorless cameras still don’t have the breadth of lenses and accessories available for them. But, then you have to ask yourself how many lenses do you actually need? The reality is that the market is moving increasingly towards mirrorless cameras. There are far more models of mirrorless cameras being released these days and far fewer DSLRs. But don’t worry, I believe that there is a long way to go before DSLRs are completely phased out.

So, to answer the question above as to which you should buy, it will ultimately come down to your budget, the type of photography that you do and what you are comfortable with.

Mirrorless cameras are here to stay and are probably the future of digital photography. As the technology improves more and more functions will be added which will make mirrorless cameras an even more attractive proposition versus DSLRs. Hopefully, this article will help you decide which is right for you.

3 Test To Do When You Buy A New Camera

A brand new camera can be an exciting purchase. If it’s an upgrade it will mean better quality images and more advanced settings. But buying a new camera also might mean getting used to new dials and controls as well as the camera itself. Cameras are not all the same and some perform better than others in different scenarios and at different settings. The only way to be sure is to test out your camera before heading out on a shoot. So here are 3 quick tests that you can do when you buy a new camera to help you get the most out of it.

ISO test

ISO is one of the most useful tools when it comes to photography. It can be the difference between being able to capture a shot and not. But it also requires careful use as high ISO will mean noise which can ruin the sharpness of a photo. But that doesn’t mean you should never raise your ISO really high, you just need to be aware of the consequences. So this is a test that I always run on any new camera that I buy.

A set of images taken at different ISOs.

Simply set up your camera on a tripod at home to take a photo of an object. Ideally, pick somewhere which isn’t too bright otherwise you may not be able to set your shutter speed fast enough. Set your camera to manual focus and ensure that your object is correctly focused. Set your ISO to the lowest it can go in your camera and adjust the shutter speed accordingly. With your camera on a timer, take a photo. Then raise your ISO by a stop or two and take another (you may have to adjust your shutter speed). Keep going, raising your ISO each time until you get as high as your ISO allows.

Once you have your set of photos, open them up on your editing software and zoom in to full size. Look at each photo at different ISOs to see at what point the noise becomes too much and your image begins to look too soft. On some cameras, this might be at ISO 1000 whereas others will be fine ISO 3200. The only way to know for sure is to test out your camera. This will then ensure that when you are out in the field you have an understanding of the limitation of your camera and how high you can set your ISO.

Left: image taken at ISO 100. Right: image was taken at ISO 102400. This shows the extremes of what high ISO can do to an image.

Image sharpness

Just like ISO, different cameras also produce different results when it comes to image sharpness at different shutter speeds. This is to do with in-camera image stabilization or lens image stabilization. But an additional factor that is often overlooked in this discussion is the weight of the camera. A heavier camera will naturally be more difficult to hold steady. When you combine this with image stabilization, you can begin to see why it’s important to test your camera before using it in a real-life scenario.

I always take a set of images like this with a new camera or lens to test its capabilities.

So for this test, you are going to use your camera and lenses at different shutter speeds to see how well it performs in capturing sharp images. Unlike the test above, you need to be outside for this one. Find something static like a building or statue (avoid trees and leaves that can be blown around in the wind), focus and then switch your camera to manual focus or lock your focus (you don’t want your focus point changing). Focus on the subject and look to set your shutter speed fast (i.e. 1/200 sec). Take a photo and then reduce the shutter speed and take another photo. Keep doing this until you get to a slow shutter speed.

You will have to play around with your aperture by making it smaller to be able to lower your shutter speed. Again, open your photo in your editing software and zoom in to check the image sharpness at different shutter speeds. You will then be able to get a good idea of what the capability of the camera is when it comes to different shutter speeds.

Shot at 1/200th sec. The image is sharp and in focus.

Shot at 1/8th sec. You can see that the edges are soft and not in focus.

Image Size

This test is about the actual image size that your camera produces. Why is this important you may ask? Because different cameras can produce different size files. This means that with bigger image sizes you will have more to play with in terms of cropping in post-production. For example, a full-frame sensor will produce a bigger image size as opposed to a crop sensor. So you will be able to crop an image taken with a full-frame camera more and it will still be big enough to print at larger sizes. Whereas with a smaller sensor camera you may have to rely more on actually zooming in or moving closer to your subject so that you are not cropping as much.

For this test, simply take a photo at the widest focal length of your lens. Try to do this on a bright day and outdoors and use a tripod if you can. Open the photo in your editing software and create several versions which are cropped to varying degrees. Export these as high res JPEG or TIFF files. Then open an A4 and A3 document in Photoshop and drop the different photos into the document. You may have to make the images bigger (or smaller) to fit the page. Zoom in to 100% view and check the image over. This will show you how much you are able to crop an image whilst still keeping its sharpness.

The reason for this test is that the more you stretch an image (i.e. make it bigger) the more resolution it will lose when viewed closely. This test will give you an idea of the cropping possibilities on your photos so that you can ensure you get them more accurate in-camera to avoid unnecessary cropping.

These 3 tests are pretty easy and quick to perform, but what you will learn from them will be invaluable when you are shooting for real. It will help you avoid those frustrating situations when you look at a photo and realise it’s not sharp. I do these 3 tests every time I buy a new camera which isn’t that often. So in reality you will only need to do this every few years.

Astrophotography Image Stacking – Astro Stacking

Hopefully you’ve been out shooting and applying what you’ve learned about astrophotography. For most there’s a fairly big learning curve with astrophotography. I was always pretty good with the computer, electronics, and the mechanical hardware, but learning to process the images was a huge challenge. Hopefully I can share what I’ve learned to help speed up your learning process.

There’s a lot to learn when it comes to taking the images from the camera to making a final image for display. You’ll find that 99% of the deep sky images that you shoot will require some form of post-processing. But before we even discuss doing any processing, let’s discuss how to best shoot the scene.

In the previous blogs, I’ve hinted about a technique that will let you get the most out of your astro images. Shooting very faint moving targets can be pretty challenging. It takes fairly decent equipment to get the really faint stuff, but beyond this, it’s important to properly photograph the subjects. There is one valuable technique that will help tremendously with processing and make the most of your data. This technique is stacking.

Let’s take a look at stacking in very basic terms. Shooting faint targets makes for generally noisy images. This is true for astrophotography as well as regular photography. This means that the photos look grainy and lack the silky smooth transition. In astrophotos, noise will disturb the transition from the target object to the dark regions. But if you shoot many photos of the same subject and stack them together, the result is far better than that of a single frame. The noise and graininess is filled in and the image will appear much smoother and complete. When I was going for the best quality images, I would generally shoot for between 10 and 20 hours of open shutter time. But again, these were for my very best deep sky images on professional level equipment. For me, that meant shooting over many nights and stacking all the data in the final image. I was shooting exposures that were ½ hour long,o I needed fewer frames. But the end result was a lot of data, that when assembled, resulted in very good data sets.

If you’re just starting out it’s not necessary for you to shoot this much. But generally the more you shoot the better. There’s a big difference that can be seen immediately in the final image. There is a point of diminishing returns, but most astrophotographers will never come close to this limit. So if you can start with shooting a couple hours you’ll end up with fairly decent data. But even shooting and stacking 10 images will be better than one single frame. The better the data, the easier it is to process into the final image.

How do we begin…? Once you have your mount aligned (see my previous blogs) the target framed and the lens or telescope focused, you can start shooting your images. Shoot the same subject, over and over. I generally use a computer or an intervalometer to take the work out of this. This allows me the ability to walk away and let the camera shoot until it’s done. Just be aware that you may need several batteries or an AC adapter for your camera. This is especially true in the cold. For your first outing, try to shoot for at least an hour of open shutter time. That means if you’re shooting 5 minute shots you’re going to want 12 of these to make an hour. It’s generally best to shoot with an exposure as long as possible, but not so long that the image becomes saturated with light fog or you begin to get star trails. I generally tried to shoot until I reached about 25-75% on the camera’s histogram. But this depends on the target and from where I’m shooting (and how much light pollution is present). Just keep in mind that 1 hour is not a magical number. Shoot more, if you have time and patience. This will make the post-processing after the stack easier and the final image even smoother.

Once you have the stack, what’s next? You need to process all these images into a single image. This is possible in Photoshop and there are some really great videos and information on the topic. So I’ll leave this learning process to those interested in doing the stacking in this manner.

The real benefit is doing the stacking in a program that is meant for processing astrophotos. There are many programs that are available to do this, some are even available for free. I used a program called MaximDL which is a high-end piece of professional astrophotography processing software. In addition to doing some processing, it also handles camera control, filter wheel control, focusing, guiding and many other aspects of shooting deep sky images. In a complex setup, it’s very beneficial to have control of everything in a single piece of software. However for those just starting out, look at getting Deep Sky Stacker (DSS). It is an excellent stacking program and is available at no cost. This allows you to practice shooting and processing images without investing a lot of additional money in software.

Be sure to take a look at the excellent instructions on the DSS website and online. It is fairly powerful and capable producing nice images. It will also allow the addition of calibration frames (discussed below), which is another very powerful feature for noise control. I generally found that I liked doing the stacking in DSS and then doing the remainder of the processing in Photoshop or similar image processing program. But that’s totally my preference. Each photographer should investigate the best workflow and combination of programs to use to produce the final image.

One really great feature of DSS is the comet stacking routine. Processing comets is even more complicated as the comet is typically in a different location in each frame. Some move slow enough not to have to worry about it. But others can move significant amounts in each frame. This typically takes some crafty processing to get a decent image. DSS takes a lot of the work out of it. This image was processed in DSS and Photoshop.

Coat hanger Asterism (CR399) and Comet Garradd

When beginning the stacking process, the images need to be quality sorted first and then aligned (or registered) first. The quality sorting can be done automatically in DSS, but I generally liked poking through the images and picking out the ones that were blurred from movement, or had clouds or planes. The registration or alignment will adjust the images up and down and also in rotation in order to bring all the frames in perfect alignment and then stack them together in one of several stacking methods. I generally prefer one of the median stacking methods.

Many of my astrophotos, including the comet photo above, were shot with professional level equipment. This equipment cost about half what my first house cost. To be fair I wanted to show what can be done with a DSR and Lens (or small telescope), so I re-processed some of my earliest images in DSS, knowing what I know now. These were shot with an Astro-modified, 6.3MP Canon 300D (Digital Rebel). This is one of the earliest DSLR’s. It was noisy and did not generally produce very clean astro images. But even with this old camera, the data was very usable and produced some fairly decent images. We’ll take a look at a few of these below:

My first modified DSLR for Astrophotography

Stacking Examples

Here are some examples of images right out of the camera and also some processed images. The first is a single frame that shows the Heart & Soul nebula (IC1805, IC1871, NGC 869 and NGC 884) as well as the double cluster. The top is out of the camera the next is after stacking and processing.

Unprocessed, right out of the camera

Stacked and post processed

The difference in these is drastic. In fairness, the single frame image was fogged by heavy light pollution. But this is a problem that will plague the majority of astrophotographers. The only way to combat this is to shoot from dark sites away from the city lights.

This next example is not as drastic. The top is out of the camera, the bottom is stacked and processed. Also included are crops of a single frame and stacked and processed images.

Single Frame and crop of the Rosette Nebula (NGC 2237)

Notice the missing details in the crop of this image.

Stack/post processed image and crop of the Rosette Nebula

The stacked image makes is much cleaner and much of the missing data has been filled in. Also note the better detail that is visible in the crop of the Rosette. This is the real benefit of the stacking method. One thing that you need to keep in mind with processing astrophotos is that it’s an incremental process. No single step is going to make a magical image from junk. Each step will add a tiny improvement, and with enough tiny steps you’ll end up with a very pleasing image. If you’re stacking many photos, most pieces of stacking software will take quite a while if you’re computer isn’t up to the task (like mine). So be patient and just let it run until it’s completed the registration and stacking processes.

Here’s another example of a single frame vs a stack. This one is of the Horsehead Nebula (B33) in Orion.

Single Frame and crop

Stack/post processed image and crop

It’s fairly easy to see the benefit of stacking when shooting astrophotos. One more advanced technique that will help reduce the noise in your stacks is called dithering. Basically this is moving the camera a couple pixels in a random direction after every frame. When using a median stacking method, objects in a different location on each frame will be eliminated. So using the stars as the alignment reference, the galaxies, nebulae or other subjects will remain in the same place. But hot pixels, satellites, planes, noise and other random effects will be in a different location, with respect to the stars, so these are eliminated when stacked. There are many guiding or tracking programs that will do dithering automatically. But even with a manual shutter release, it can help tremendously if you manually move the mount between exposures. It seems like a hassle, but dithering will add a fairly significant level of improvement. None of the images above (except the comet image) used dithering.

Another helpful addition is to add calibration frames. These will serve to help remove additional noise and other artifacts from the images. Dark frames will help remove hot pixels, Bias frames reduce read noise and flat frames will help clear up any dust spots or other specs that are caused by looking through the lens or telescope. There is a superb description of this in the FAQ section here. The newer more modern cameras tend to provide better noise and hot pixel control, so calibration might not be needed. But at the very least, flat frames should be used to ensure the removal of artifacts caused by a dirty lens or sensor. It will also help reduce any vignetting that occurs in the images. Remember: incremental improvements.

In the final installment of this Astrophotography series, we’ll discuss some of the details of going from a rough stacked image to the final image. This is where a lot of the magic happens so I hope you’ll stay tuned. In the meantime get out and shoot. See you soon.