Seven Sisters

I took the mount for a test drive and it was a challenging first time. After several try's i was able to do a rough polar and 3-star alignment. Far from perfect the mount was pointing close to the chosen objects, so why not some photos?

I was not prepared to do exposures, the plan was to test the mount. It was impossible to resist and the camera was out in a flash. Unfortunately i was low on battery and could only capture a couple of photons.

The target was the beautiful M45 - Pleiades Star Cluster. I plan to revisit this part of the sky to do a project with better equipment, more exposure time and better processing.

Image Data: Pleiades Open Star Cluster (Messier 45)

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens

Focal Length: 55mm

F/Stop: f/6.3

Exposure: Stack of fourteen 90-second exposures (21 minute total exposure)

Mount: Sky-Watcher HEQ5 Pro SynScan GoTo (EQMOD Control)

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 800

White Balance: Custom, set on sky background

In-Camera Noise Reduction: Off

Filter: None

Date: October 03, 2010

Location: Beja, Portugal

Calibration: Dark frames were subtracted from each individual light frame to remove the thermal signal. Fourteen Dark Frames.

Processing: Calibrated, aligned and stacked in DSS. Levels, curves, brightness and contrast enhancement, noise reduction, cropped, resampled in Photoshop. Carboni Tools.

The Mount

It finally arrived, a brand new computerized german equatorial mount: Sky-Watcher HEQ5 Pro SynScan GoTo.

With this marvelous piece of equipment i hope to greatly improve my astrophotos.

Stacking and Calibration

Image stacking and calibration is used in digital astrophotography in order to enhance data in photos.

To put it simply these methods are used to improve the SNR (Signal to Noise Ratio), reduce long exposure and ISO noise in images taken with DSLR's.

The example shown here is not breathtaking but was obtained using these methods. This Andromeda Galaxy (M31) image lacks exposure time but that can not be increased using only a fixed tripod without showing star trails.

Image Data: Andromeda Galaxy (Messier 31)

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens

Focal Length: 53mm

F/Stop: f/6.3

Exposure: Stack of ten 15-second exposures (150 second total exposure)

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 1600

White Balance: Custom, set on sky background

In-Camera Noise Reduction: Off

Filter: None

Date: September 12, 2010

Location: Beja, Portugal

Calibration: Dark frames were subtracted from each individual light frame to remove the thermal signal.

Processing: Calibrated, aligned and stacked in DSS. Levels, curves, brightness and contrast enhancement, noise reduction, cropped, resampled in Photoshop. Carboni Tools.

Afocal Moon

It can be called the "hand afocal" method. Holding the camera with both hands and closing it to a 25mm eyepiece (EP) that was mounted on the telescope.

Image Data: Moon (Waning Gibbous)

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens / Trust 60mm Refractor with 25mm EP

Focal Length: 18 mm / 900 mm

F/Stop: f/4 / f/15

Exposure: One 1/500 second exposure

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 800

White Balance: None

In-Camera Noise Reduction: Off

Filter: None

Date: August 29, 2010

Location: Beja, Portugal

Calibration: None

Processing: Resampled.

Image Data: Moon (Waning Gibbous)

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens / Trust 60mm Refractor with 25mm EP

Focal Length: 46 mm / 900 mm

F/Stop: f/6.3 / f/15

Exposure: One 1/60 second exposure

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 800

White Balance: None

In-Camera Noise Reduction: Off

Filter: None

Date: August 29, 2010

Location: Beja, Portugal

Calibration: None

Processing: Resampled.

Processing

Processing is a key feature in digital astrophotography. Basically each pixel in a photo file has a corresponding code number that represents color and it's this data that is filtered and /or enhanced. Astrophotographers use many different programs and applications to enhance their photos, but many may ask if what we see in this photos is real.

Jerry Lodriguss, an experienced astrophotographer, has a great article about this subject here.

Since i'm not doing science what i want to acomplish is that my photos be the more pleasant as possible, just like if we where right there journeying in a spaceship.

I have to say that my processing experience is almost zero and im still in the long learning road.

Image Data: Ursa Major

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens

Focal Length: 18mm

F/Stop: f/3.5

Exposure: One 3-second exposure

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 800

White Balance: None

In-Camera Noise Reduction: Off

Filter: None

Date: July 31, 2010

Location: Beja, Portugal

Calibration: None

Processing: Color ajusted, contrast increased, noise reduction, resampled in Digital Photo Professional

And after doing a little simple processing in the photo from the last post, the one filled with light pollution:

 

Image Data: Deneb - Vega - Altair

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens

Focal Length: 18mm

F/Stop: f/3.5

Exposure: One 15-second exposure

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 400

White Balance: None

In-Camera Noise Reduction: Off

Filter: None

Date: August 01, 2010

Location: Beja, Portugal

Calibration: None

Processing: Color ajusted, brightness and contrast enhancement, noise reduction, resampled, sharpened in Photoshop.

Light Pollution

So i had this great camera on my hands, zero experience in astrophotography and still missing lots of equipment.

But i wanted to capture all that beauty in the sky, so i took the camera out and started shooting...

That night i met one of the nuisances of astrophotography: Light Pollution.

I found out that my observation site is on a orange zone leaving my photos with an unpleasant brownish background...

Image Data: Deneb - Vega - Altair

Lens/Scope: Canon 18-55 f/3.5-5.6 EF-S Zoom IS Lens

Focal Length: 18mm

F/Stop: f/3.5

Exposure: One 15-second exposure

Mount: Fixed Tripod

Guiding: None

Camera: Unmodified Canon 500D (Digital Rebel T1i)

Mode: Raw

ISO: 400

White Balance: None

In-Camera Noise Reduction: Off

Filter: None

Date: August 01, 2010

Location: Beja, Portugal

Calibration: None

Processing: Resampled

The invention of DSLR

While doing my first moon observation through a telescope in many years, this friend of mine presented me with a wonderfull piece of technology he had, a DSLR (Digital Single-Lens Reflex) camera.

I knew of the existence of this cameras, but never ever had tried one with a telescope. Afocal astrophotography of the moon was very easy and from that moment on i knew the road i was walking.

It was decided and there was no turning back, i wanted to be in the midst of the stars.

Another small step was taken and i bought a Canon EOS 500D.