Getting my DSLR camera astro-modified
When I heard that after so many years, and over 2500 astro
conversions, Andy Ellis of ‘Astronomiser’ was hanging up his
tools – I immediately did some research and reached a decision.
My research was – ‘what are the advantages and disadvantages of astro
modifying my camera’ and I have sort of summarised my findings
below.
The decision? I am posting my DSLR to Andy ASAP, having got one of his last conversion slots. he came highly recommended and I haven't been able to find someone else in the Uk at the moment who would do it. Ideally I wanted to wait another year ro so until I was better at post editing but, as is always the case, I've decided to jump right in and get it done now. 😕
So, what is astro modifying a DSLR all about?
I have a Canon 800D. It is several years old now. It has become my astrophotography camera. I tend to use a compact Canon digital zoom for my daily photography as it is compact, easy to slip into a pocket on my travels and takes really good photos.
Now my Canon camera, like other Canons, have a fitted filter that cuts out swathes of red light at a particular frequencies (about 75% of the light in the red band I think) – and this can really affect the Hydrogen Alpha band of emission nebulae. Thus to have any chance of capturing the red in nebulae etc, then I have to do lots of long exposures - making an astrophotography session, very long!
Remove the filter and the cameras red response gets improved
by a whopping x4 in this Hydrogen Alpha band, thus reducing the amount of
imaging time required. The mod will also improve my milky way photos, shots of
star forming regions and enhance any hydrogen alpha in galaxies.
So, I am getting the rear filter removed. This is a UV/IR
cut and colour correcting filter so I am told. Hence its an ‘IR Mod’. They key
here is its removal stops the colour correcting bit which is where the 75% of
light loss occurs.
At least I think this is right. As always, I flag up my long-standing
caveat – I’m a beginner at astrophotography and so I may make mistakes, for
which I apologise! If you think I have anything wrong, drop me a comment and I
will correct it immediately. Remember, this is a blog written by a beginner,
for beginners!
Back to my astro-mod. I think Andy will remove this rear
filter and reposition the sensor to correct for the loss of the filter glass.
So, lets move onto the advantages
of doing this mod – I have
already raised a few:
·
Removal of the filter will allow more sensitivity
light to the Hydrogen Alpha band -
easier to capture faint red wavelengths!
·
Increased sensitivity means I can capture more
detailed vibrant images of DSO’s in shorter imaging sessions - more accurate
colours
·
I will be able to do better narrowband imaging
·
With shorter imaging time, my images should
suffer from fewer stars overwhelming the main DSO I am imaging
·
I can still use my existing DSLR lenses and Zenithstar 61ii small
refractor
Disadvantages of doing the
mod:
·
My camera will now capture all images in the red
spectrum and so I will need to make white balance adjustments if I want to use
the camera for daylight shots OR I can use a clip in astronomic OWB filter to
compensate. I read somewhere that setting a WB of 2500K for daylight
photography will work but only time will tell.
·
an astro-modified camera might struggle with
capturing detail in bright objects like the moon due to its increased
sensitivity to red light.
·
For capturing lunar details or wide-field shots
with a high dynamic range, an unmodified camera might be preferable.
·
I may lose automatic focusing on my lenses (not
an issue for me as I tend to use them all in manual focusing mode at night)
·
The costs of the astronomic filter and
conversion
·
It will void my factory warranty (but that was
already out of date anyway)
·
I am going to get post editing frustration as I
will need to do colour corrections to my milky way landscapes – they will have
a purplish hue! So, I will need to re-write my cheat notes about post editing
work flow.
Is the modification worth doing?
Jury out on that as far as
I make out on various forums. For everyone who says yes, someone says no! Many
say invest in a tracker instead for any landscape photography and don’t mod the
camera.
I have decided to take the plunge. If nothing else, it will
force me to master colour correcting techniques in Affinity Photo!
Below are some of the videos I looked at:
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