4 replies to this topic

[JAB37]

I'm interested in astro-modding a DSLR.  I am trying fill in a gap in my astrophotography.  I'd like to get wide field shots such as Milky Way, Orion/Barnard's Loop and other big targets that incorporate the Ha component that the regular DSLR sensor misses.  I've looked over LifePixel's website but I'm not sure what mod to choose.  I'd like to use a used Canon 6D.  

 

Are the Ha modded cameras only picking up Ha signal? And the rest of the image is made using a regular DSLR sensor?

Or do I get a full spectrum mod and use HaLRGB filters?  

 

How are you guys managing these types of images?

 

This is an example of the type of image I am after (this was borrowed from a Flickr acct):

 

 

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[maxsid]

Ha-mod transmits everything down to Ha and cutting off IR - that's what you need.

Full-mod transmits everything including IR. You don't want this.

 

I have a full-modded Nikon and have to use a UV/IR cut filter with it. Otherwise the stars are bloated by IR.

[StargazerLuigi]

The modification to my Nikon simply boosted its response to Hα -- by replacing the IR Cut filter with one more transmissive to Hα wavelength. It still functions as a normal 'terrestrial' camera, however for daytime images a custom white balance will be needed. The outfit that did my conversion recorded a custom white balance on the camera. Of course, you can also create your own custom white balance by shooting a grey card. 

 

I did not get a full spectrum mod, so I'll step aside now and let those who did chime in.

[bignerdguy]

The Ha mod includes signal in the Ha band as well as the normal frequencies so it gets a broader bandwidth of light.  A Full spectrum mod by comparison get ALL IR and UV bands as well as all others frequencies.  With both you will need to make at least one adjustment to your daylight photos as it requires a custom white balance.  If the Ha filter you use for the Ha mod does not have the same thickness as the original, the sensor will need to be moved forward towards the front of the camera to account for the missing glass.  With a FS mod if you only remove the filters and don't replace them with a clear glass alternative (as i did with my 60D) then the sensor will need to be moved even farther forward to compensate. if not then the camera will not be able to achieve focus at infinite distances very well using normal lenses.  

 

The nice part of a Full Spec mod is you can then use specific lens filters to do IR only photography.  It makes for some cool effects.  However the use of a lens end IR cut filter is needed for all daytime photos along with a custom white balance.

[asanmax]

You basically have two options that are the most popular among our customers.

 

1. Visible + H-alpha: The stock filters are replaced with a custom UV/IR cut filter, allowing visible light and H-alpha (Ha) and SII to pass through. No external filters are needed, though using light pollution filters can improve results when shooting in urban areas.

 

2. Full Spectrum: This option involves either a "naked sensor" modification or replacing the stock filters with custom clear glass featuring BBAR coatings. It’s ideal if you're interested in both astrophotography and infrared (IR) photography. External filters are required, and you can choose between clip-in or on-lens options.