erl
Question for astrophotography folks:
Is there any reasonable way to shoot with standardized filters with an off the shelf dslr? I have a home decor project in mind that id like to use a standard SDSS g and r for (or maybe a couple of the hst filters depending on how I’m feeling). But like I don’t really wanna be constrained to Nikon’s R, G, and B filters.
erl
@thomasfuchs I was thinking that'd be the easiest way, but wouldn't you wind up effectively getting the product of the transmission function associated with the filter and something associated with each of the three RGB channels on the camera's chip? Usually telescopes just use monochromatic ccds with known and broad response functions so I don't really know how to deal with the narrow color channels in a dslr
erl
@apalu @thomasfuchs Ahh, ok yeah I guess I was imagining the filters being comparable width to the camera's bands, but that's probably not true. That makes things a lot easier lol
apalu
@erl @thomasfuchs you do get a product, but I'm not really sure how that's a problem. :blobfox3c: if you need precise numbers you can get them with a linear equation, otherwise the bands on the filter are pretty narrow relative to the bands on the camera so you can just pick the brightest of r,g and b.
erl
@apalu @thomasfuchs yeah, that'd be the reasonable thing but I'm just looking at sdss images which aren't necessarily timed for the individual sources on their plates, so sometimes they get really nasty when there's a bright source.
This is a project mostly just to make a pretty picture for my wall so I assume I'll be able to get by by reducing the aperture from what sdss uses (2.5m i think?) down to whatever I can afford and tinkering with exposure times.
Idk honestly this is maybe just me looking for an excuse to dabble in astrophotography
apalu
@erl @thomasfuchs if you don't mind me asking, why not reduce the exposure time, if the problem is that the channels are being saturated?
erl
@apalu @thomasfuchs yeah, I was kind of thinking about sdss r and g, which are both kind of broad. Part of my motivation for taking photos myself is actually that the sources are bright enough that the sdss images look awful and are a bit saturated and I'm pretty sure I could do pretty well with a cheapish telescope and my camera.
But I also really like a couple of the hst filters for no rational reason so they could be fun to play around with
apalu
@erl @thomasfuchs I suppose it depends on the filter. HST filters are very narrow.
erl
@thomasfuchs What sorts of magnitude limits are typical for astrophotography setups? (I know this is extremely dependent on a lot of parameters, but I literally have no reference for what folks can do in their backyard)
realistically I'm wanting to look at extended objects which peak at like 15-16 mag/sq arcsec which is screaming bright for big telescopes but seems like maybe a bit too dim for something I can get my hands on
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