A Camera Comparison

Which cameras, you ask? Thank you for asking. In this case, it is a DSLR and a dedicated astronomical camera. You may be familiar with a DSLR, the digital version of a single lens reflex camera. I am using the camera used for the last installment of this blog, a Canon Xsi. It's really a uppercase X, uppercase S, lowercase I, but auto correct won't allow that. Moving on. The astronomical camera is a QSI 683, which is a cooled (as in temperature) camera used only for connecting to a telescope to take images of the night sky. The size of the sensor (ie, the chip) in the QSI is slightly smaller, but they are almost the same size. That difference is reflected in the size of the field each one images. For the comparison, I imaged the area of M81 and M82.

M81 and M82, Canon DSLR

This is the DSLR image showing both M81 and M82. Both are galaxies; M82 edge on, M81 more or less face on. M81 is in the upper right corner, M82 the small fuzzy spot in the lower left.

M82 identified

This is the same image, just showing M82 so it's definitely identified.

M82 with QSI

This is the QSI image showing M82. Obvious difference, huh? So what was the same in these two images? The images were taken on consecutive nights (I couldn't get both on the same night), the exposure time was 2 minutes for both, same telescope. Only difference was the camera. (Integration time was actually longer with the DSLR, which should have made for a better image.) I kinda like this image of M82.