DSLR Documentation and Reduction

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).

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-Bernd

All,

I think I have a simplified version of the Excel reduction sheet ready to go. I think the math behind it is sound (see attached PDF), but I would like someone else to check it to make sure I didn't neglect anything.

For this introductory-level reduction method, air mass correction is absent, but then again the difference over the field-of-view of a DSLR camera should be small. This would simply correct the instrumental magnitudes going into the equations anyway so I think it's fine.

Let me know what you think,
Brian

Hi!

Brand new:

http://www.astrosurf.com/buil/us/iris/iris.htm

Version 5.58 now has a command that does batch conversion (RAW => CFA FITS )

CS
HBE

Hi!

I just saw that even tho the text here

http://www.willbell.com/aip4win/AIP.htm

refers to AIP4Win 2.3.0, it actually links to a ZIP with version 2.3.1.

I know that Richard Berry wanted to change a few things wrt DSLR raw extraction as reaction to feedback in the forum.

CU
HBE

Excel Reduction: Introduction

This page is for varios Excel reduction techniques.  Upload your Excel sheet and give a breif (one-paragraph) introduction to how it is used.  Just plug in the general formulas, don't lock any cells (yet), and make it easy to use by someone with a little Excel experience.

We'll evaluate which we think is best for the general public and whichever we think is best will be used as our "standard" reduction sheet.  Brian will modify the worksheet to include the equations for full uncertainty analysis before the sheet is added to the general CS website.

Please name the files by your username without spaces (i.e. bkloppenborg.xls) and add a new section to this page following the examples below (note, you'll need to rename your file on your computer before attaching it to this page).

Heading 2 (filename.xls)

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