Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 02/17/2015 - 18:56
I am extremely new to photometry. Though I have read a few helpful forums, I haven't quite found the answer I was looking for (or, to my own fault, I missed it). Does anyone have a suggestion for a first time dslr purchase for someone just beginning photometry, also keeping in mind a limited budget ($300-$650). Thank you very much.
Sincerely, Eric DeCamp
hey eric
i just got back into variable star work after a long hiatus. anywho i jumped into the dslr world and highly recommend the nikon D5200 which i purchased for this work. canon's are also great cameras as well, i also own a canon dslr. the main thing to look for is a flip out and rotatable view screen since many time the camera will be pointing straightdown and this way you can see what you are imaging without straining your neck and back. for the nikon d5200 i also got from best buy a remote infrared camera trigger which eliminates camera shake. i use the the nikon with a 500mm f5.6 lens and a 20 sec guided exposure and ISO 200 gets me easily down to about a magnitude of 11.5, if i go to 30 sec it is about 12.5
I've got a Canon EOS 1100D (Rebel T3 in the US) and it fits very nicely in the budget in question:
PROs: lightweight body, easy to adapt to telescopes and many legacy lenses (adpaters to almost any mount system available), sensor is quite low noise, pixel size is ok. As with all EOS DSLRs: Snap-in filters available for pretty-picture astrophotography. Many useful compatible third party software products available like AstrophotographyTool APT : http://www.ideiki.com/astro/Default.aspx
CONs: display is fixed, no mirror-lock-up, live view could use a one notch stronger zoom level.
CS
HB
Hi Eric,
I also use a Canon 1100D and find it works well for photometry. Do get a good fixed focus lens instead of the standard kit zoom lenses. If you plan on using a camera tripod then I'd suggest a lens with focal length between 80mm and 200mm with fast f-ratio.
Note: if you plan to use AIP4Win it does not open 1100D RAW files. You'll need to convert them to DNG format using Adobe DNG Converter (it's free). Cheers,
Mark
Thank you for the fantastic responses. One more detail I forgot to mention. I no longer have a telescope at the moment. Will any of the cameras you mention still be successful in measuring any magnitude variation without a telescope and on their own with a tripod, or is a telescope absolutely necessary? Again, I'm looking for the simplest start possible with a camera while still contributing solid research.
Thank you.
Hi Eric,
no need for a telescope, a standard fixed focal length camera lens of 80 to 200mm will do an excellent job of photometry. Don't try to use the kit zoom lens that comes with the DSLR as the image quality is generally not good enough.
Stick with variables brighter than V mag 8 to start with, there are plenty of targets to keep you busy.
You might consider enrolling in the CHOICE DSLR Photometry course (http://www.aavso.org/choice-astronomy) starting March 2nd. Even if you don't have the camera yet you'll get a good understanding of equipment issues, calibration, software, etc. Cheers,
Mark
Hi Eric
I use a Canon 1100D (after talking with Mark) with an EF f2.0 100mm USM lens, mostly on a tripod but sometimes piggyacked on a scope (8" SCT), depending upon the exposure required. I contributed visual observations for a few years (and still will for some targets) but I've recently started to submit DSLR photometry observations to AAVSO.
I highly recommend Mark Blackford's DSLR photometry course.
David