Astrophotography

[fort384]

Sorry we colloquially refer to it as wide field in astrophotography but the more common photographic term would be wide angle. Some really neat views of the Milky Way and night sky can be had with a short, fast, prime lens, or even a stock lens with your DSLR.

 

[fort384]

Fantastic photos. That's like my dream setup .. until then I just carry around my miniscule ETX-125. I'm still stuck in the "start" mode lol

Hey that's a nice scope. It was the first "serious" scope I owned but it is not well suited to photographic work. I saw some great visual through it though.

 

[astroNikon]

Fantastic photos. That's like my dream setup .. until then I just carry around my miniscule ETX-125. I'm still stuck in the "start" mode lol

Hey that's a nice scope. It was the first "serious" scope I owned but it is not well suited to photographic work. I saw some great visual through it though.

I started out with a etx-90 UHTC years ago. Then I sold it and bought the 125 (used for the same price I sold the 90 for). It's about all I can afford as the next "jump" up for some good stuff is just way too much $$$.

I use my dslr on it off the back, straight through as I think the mirror adds some distortion even though I have to counterbalance it. But it is what it is and it's fun when I use it.

When I hit the lottery, I'll upgrade.

 

[fort384]

Nice. Yeah it is hard to get flat all the way to the edge of the field - one of the reasons I prefer refractors with field flatteners in the imaging train. I have never photographed through an SCT though the longer focal lengths are attractive and there are impressive examples out there. I would imagine the next scope I purchase will be a 12 or 14" SCT as I am about at the limit of what is practical with a high quality refractor. You get much above 5" on a refractor and the cost, weight, and awkwardness start to skyrocket exponentially. That is a couple years away though. For now lots more to capture with the 127 APO.

 

[Ironlegs]

Beautiful pictures, i always loved astrophotography

 

[MikeFlorendo]

It depends on the target - I rarely take straight luminance frames though as is the case with the elephants trunk I will add Ha in as a modified luminance layer of sorts if the target warrants.

Currently I use an explore scientific 127mm apochromatic triplet carbon fiber refractor which is essentially a very nice 952mm prime lens at f/7.5. With this glass I get no detectable chromatic aberration.

The main camera is a Santa Barbara Instruments Group thermoelectrically cooled Mono CCD with an electronic filter wheel mounted between it and the scope. However I also image with a no frills Canon 1100D from time to time.

Installed on the imaging scope is a Moonlite Focuser which is driven by a high resolution 35,000+ step stepper motor that automatically adjusts focus per the filter I am imaging through and the ambient temperature.

It all rides atop a Sirius EQ-G German equatorial mount. A second 50mm guidescope is piggybacked on the 127 that has a mono CCD camera attached and is only used to provide tracking updates to the mount based on the position of a selected "guide star". This system sends corrections to the mount any time the guide star moves more than a quarter of a pixel on the CCD chip of the guide camera.

Most of these images are hours and hours of integrated subframes at between 8-10 minutes each. It generally takes all night or multiple nights to produce enough data for a single image. Without proper tracking stars start to streak in as little as 5 seconds depending on the location of the target in relation to the celestial pole, so proper tracking and guiding are as crucial as the main optical tube assembly to the final outcome.

All of it sits atop a concrete pier embedded 5ft into the ground with about 3 tons of concrete and rebar. The whole system is driven by a myriad of software and hardware that is piped underground to my man cave/observatory control room 50 feet away.

Well I guess I'm not going out tonight with my point and shoot!

Insane shots! How could anyone even start to critique? Here you go that star in the very right hand top is out of focus. ~shrugs my shoulder~ Seriously though they are very beautiful shots. I am curious as to what they look like pre post since it appears you put lots of hours into them? I have always been the guy who has to look behind the curtain.

 

[fort384]

There are generally around 100 frames that compose a single image (usually 5+ GB of data)... individual sub exposure light frames are combined with bias frames to substract inherent noise, dark frames to subtract thermal noise, and flat frames to provide even illumination across a field. I would post an individual light frame, but they are 32 bit FITS images that would appear as nothing more than a black frame on a normal monitor without performing a massive stretch on the image. Of course it would also be black and white, and only represent one color channel (or a narrowband in the case of an image through the Hydrogen Alpha 7NM filter). Let me know if you want to play with one - I'll upload to dropbox and send you a link (let me know which image as well). They won't open in Photoshop, however... you'd need to convert to 16 bit first.

 

[JustJazzie]

Wow! Welcome to the forum! I can't wait to hear what you have to teach us! Thanks for joining, and sharing your work.

 

[MikeFlorendo]

There are generally around 100 frames that compose a single image (usually 5+ GB of data)... individual sub exposure light frames are combined with bias frames to substract inherent noise, dark frames to subtract thermal noise, and flat frames to provide even illumination across a field. I would post an individual light frame, but they are 32 bit FITS images that would appear as nothing more than a black frame on a normal monitor without performing a massive stretch on the image. Of course it would also be black and white, and only represent one color channel (or a narrowband in the case of an image through the Hydrogen Alpha 7NM filter). Let me know if you want to play with one - I'll upload to dropbox and send you a link (let me know which image as well). They won't open in Photoshop, however... you'd need to convert to 16 bit first.

I really appreciate the offer but as I was posting my wife walked in and I showed here your shots and she said "how the hell did he take those?" I gave her the lame dumbed down concrete pedestal, crazy computerized tripod and hours and hours of patience explanation. She gave me that look like don't even think about it! So I probably shouldn't even start to play with it.

 

[Scottuk]

Stunning. My hat off to you sir. You have a passion, you've invested and look at the product. Fair play.


Sent from my iPhone using Tapatalk

 

[fort384]

Thanks Scott and all. Glad you liked them.

 

[fort384]

Finally, after weeks of clouds, I was able to add to the portfolio last night: M16, the Eagle Nebula, in false color Hydrogen Alpha with RGB star field.

The Eagle Nebula was made famous by the Hubble Telescope "Pillars of Creation" photo. My resolution is not quite as good, but still a pleasing image.

The image contains roughly 130 individual frames (bias, dark, flat, and light frames) and contains roughly 3 hours of shutter time through 4 filters: Hydrogen Alpha, and R,G,B.

Thanks for looking!

 

[pgriz]

That is just superb.

 

[AlanKlein]

Awesome photos. Very nice site and video there.

 

[minicoop1985]

Dude. Seriously. Wow.