Saturday, 28 February 2015


There are a few ways to get infrared photos from your digital camera. They vary in potential and complexity. Here's a list of the main options I can think of in cost order:
  1. Infrared Filters
  2. Infrared Filters + Tripod
  3. Conversion (Compact)
  4. Conversion (SLR)
  5. Conversion (Mirrorless)

1. [Infrared Filters] - If you're lucky enough to own a camera that lets enough infrared light onto the sensor that it allows you to take IR images hand-held by simply adding a filter in front of the lens then this is cheapest option for experimentation. There are a few factors involved that make this more achievable, these are:
  • An internal filter that doesn't block too much IR light
  • A camera that is very good with high iso (thus exposures can be boosted relatively cleanly)
  • A fast lens (large apertures / small f-stop values) - f/2 or below is helpful
Cameras that are good for IR will like be in either the first category or the second two. A couple of examples of the latter are: the Fuji X100 and the Sony RX1. Although these tend to be more expensive cameras, if you already have one then just adding a filter is cheap and simple.

2. [Infrared Filters + Tripod] - Any camera can use an infrared filter in front of it's lens (although see 'tips on filters' below), but if your camera doesn't fall into category 1 and thus isn't very sensitive to infrared light then you will need to use a tripod as well. This will be because your exposure times are just too long. Unfortunately this means shots of moving subjects are out unless you want them blurred. The fact that it does introduce motion into your images is a really nice aspect at times however so use it as an excuse to experiment with that at the same time. Infrared is great for water and trees and they can look even more ethereal and interesting as long exposures.

3. [Compact Conversion] - If you are a bit more serious about infrared you can get a compact camera converted or you can buy one pre-converted by a company. This will cost a bit more

4. [DLSR Conversion] - Although I personally feel that mirrorless cameras offer greater potential for infrared photography, there's no arguing that many DSLRs are very cheap now and they're certainly not a terrible option for conversion. They can provide faster focusing and being able to see through the lens can be useful. If they have live-view they can also show you what IR you're taking, but ones with that feature might be more expensive.

5. [Mirrorless COnversion] - In my opinion mirrorless cameras offer the best option for conversion of any camera type and especially for multiple spectrums. Apart from being smaller/lighter there are several reasons for this:
  • Electronic viewfinders will show the IR effects in real-time
  • Legacy lenses can be adapted cheaply and they often have IR focus markings
  • Options to put filters inside the adapters are now emerging (OWL)
  • AF is more reliable with different spectrums
  • Focus peaking works for IR just like colour and its brilliant

     Tips On Filter (mostly for options 1 & 2)
Your choice of filter type here is rather limited when using a non-converted camera. Not aggressive enough and you will just get a red image (probably because the filter will look red to the eye (600nm or less). Too aggressive and the internal filter will not let enough light through. Exposure times will be too long or images will just be black (800nm or more). A good sweet spot is 700nm. 720nm is the most common, like the Hoya R72, but you can get very cheap filters off of ebay (usually from China) for less than £10. This is what I would advise if you just want to dip your toe into the infrared photo world.

For filter advise with full spectrum conversions I will write a more detailed post (coming soon)

     Notes On Conversion (options 3-5)
Almost all digital camera come with a filter in front of the sensor that blocks out most infrared light (which is is done to improve colours). Luckily this filter can be removed and replace with something that allows infrared light to pass through to the sensor. There are 3 main options here*:

  • Infrared [Choices] (replacing camera's hot-mirror with an infrared filter)
  • Dual Colour (lets in colour and infrared, but not ultraviolet)
  • Full Spectrum (lets in colur, infrared & ultraviolet)

* but it's worth noting that most will damage or destroy your ability to take colour images, so this is only really advised on an older camera that you have, or if you are buying a second camera / camera body.

     ** IR Conversion Choice 
When considering converting a camera you have a few options. It all depends on how much colour you want to allow in as well as infrared. 565nm (often refered to as 'goldie') for example, will let in a lot of colour. This will increase your options for processing, but if processing images to pure black and white infrared there will be less contrast (skies won't be as deep black).

Although it depends on what you like the look of and how flexible you want your camera to be I am going to make a suggestion here. Unless you absolutely hate colour IR, or you're converting a cheap DSLR, or you have plenty of money to burn on an experimental conversion, I'd advise to NOT have an aggressive internal infrared filter installed (like 850nm or more). The reason for this is that you can convert your camera to the least aggressive IR type that you like, let's say 650nm. You can then add filters to the front of the lens that are higher than that (720nm, 850nm etc.) and have the best of both worlds. This will work on DLSR's if they have live-view, but is a much better option on mirrorless EVF cameras.

No comments:

Post a Comment