DSLR Documentation and Reduction

I haven't noticed the Teams before and have now joined the DSLR team. I have uploaded my spreadsheet for reduction under "Final Reduction". This is the sheet I have used all along the campaign and it has worked very well. It has an automatic calculation of Tc, k' and Zp using the least-square method between the compairsion stars. After the coefficients is calculated they are applied to the variable star (epsilon in this case). Read more

Credible DSLR reports have been received that epsilon Aur has been slowly but steadily brightening during June, perhaps by as much as 0.10 mag +/- 0.02 mag, toward 3.70 lately. Corroboration requested.

Imaging with a DSLR and Simple Tripod

Most of the imaging procedures for DSLR photometry will be very familiar to those who have dabbled in astroimaging. The goal of photometry, however, is to accurately record, not appearance, but the relative brightness of each star compared to other stars in the field. This accuracy is achieved first, by calibrating each image to eliminate both electronic and optical anomalies of the camera and second, by stacking multiple exposures. Stacking increases the signal (star photons) to noise (background photons) ratio and averages out the effects of atmospheric variability. Also, be sure to record all your images in "RAW" format.Read more

Hello to all!!

I have made a presentation of the procedure in IRIS to some friends but the argue that this procedure seems to confusing. One of them, that he is already active to the project and sending data to jeff Hopkins, told me that because of the small exposure time there is no great need for bias,dark,flat frames. So i went on to remove these steps and after many tests with our sample data and others I managed to simplify a little bit the procedure. So perhaps, this (http://www.citizensky.org/teams/dslr-documentation-and-reduction/iris-tu...) can be a beginner's tutorial and the one that we have now to become an intermediate tutoria (since we take into account more accurate steps).

Perhaps, someone else can check this to see if it is correct. One point that still have not clarify is the adding of images. I see that both arithmetic and median works, but i suppose that median should lower the S/N. So is it better then to select only the arithmetic method?

Regards,Read more

A finder chart with all the check and comparison stars from the Beginners Tutorial Reduction spread sheet.

For the curious: derived from a photo taken in mid February 2010 with an Olympus E 420, f= 55 mm, f/4, 9  x 8 sec, ISO 400, defocused.

It shows stars in the field down to approx 8 mag.

Attached is the ready-to-use PDF version.

I checked the star labels by putting a printed page over a flat screen showing a Stellarium view of the field, so I'm pretty confident they are right :-)

I also attached  an editable  version (OpenDocument Graphics format, created with StarOffice).Read more

Hi team!

I made a test run of the Iris tutorial with the sample images that Tom donated. I had a few problems so I changed the tutorial a bit, especially at the point when you extract the green channel.

I also made some screenshots that I sent to Brian in a ZIP (you can't attach ZIP files here and I was too lazy to attach each screenshot individually).

CS
Heinz-BerndRead more