May 22, 2015, 04:52:03 PM

Author Topic: Deep Sky Astrophotography  (Read 36829 times)

Crosswind

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IR sensitive sensor at daytime?
« Reply #195 on: April 11, 2015, 05:28:13 AM »
Hi there, I have a quick question to all people using cameras like the 60Da or the like, which have no IR blocking.

How would the images look like at daytime as it is not recommended to take photos at that time with such cameras...? If they look a lot weaker than they would taken with a normal camera, could it be a possibility to convert them into Black&White to still get good images at daytime? How much difference is there

thx in advance

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IR sensitive sensor at daytime?
« Reply #195 on: April 11, 2015, 05:28:13 AM »

jrista

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Re: Deep Sky Astrophotography
« Reply #196 on: April 12, 2015, 01:20:25 AM »
The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.)


You should get better Ha exposure depth with a 60Da than an unmodded camera, but the changes in that camera's design by no means make it unusable for daytime photography.


The new Nikon D810a, on the other hand, was explicitly designed as an astrophotography camera. It is not recommended for use as a daytime photography camera. It's price is so prohibitive that it's not even recommended as an astro camera, as for hardly any more (and in some cases possibly even less) you can get a proper cooled mono astro CCD camera with filter wheel, and get significantly better exposures than any DSLR.

StudentOfLight

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Re: Deep Sky Astrophotography
« Reply #197 on: May 05, 2015, 01:26:22 PM »
The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.)


You should get better Ha exposure depth with a 60Da than an unmodded camera, but the changes in that camera's design by no means make it unusable for daytime photography.


The new Nikon D810a, on the other hand, was explicitly designed as an astrophotography camera. It is not recommended for use as a daytime photography camera. It's price is so prohibitive that it's not even recommended as an astro camera, as for hardly any more (and in some cases possibly even less) you can get a proper cooled mono astro CCD camera with filter wheel, and get significantly better exposures than any DSLR.
A few years back, when my previous employer bought a high-end FLIR camera I was sent on a Infrared-Thermography course. We were taught that most IR light does not pass through glass, only near-IR. Based on that, would I be mistaken in thinking that it is a bit of a waste using specialized IR cameras with conventional lenses? Wouldn't the glass likely absorb a huge proportion of the incoming IR thereby nullifying the gains on the sensor side? Would these dedicated astro camera sensors be more suited to mirror-type telescopes?
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jrista

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Re: Deep Sky Astrophotography
« Reply #198 on: May 05, 2015, 07:17:32 PM »
The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.)


You should get better Ha exposure depth with a 60Da than an unmodded camera, but the changes in that camera's design by no means make it unusable for daytime photography.


The new Nikon D810a, on the other hand, was explicitly designed as an astrophotography camera. It is not recommended for use as a daytime photography camera. It's price is so prohibitive that it's not even recommended as an astro camera, as for hardly any more (and in some cases possibly even less) you can get a proper cooled mono astro CCD camera with filter wheel, and get significantly better exposures than any DSLR.
A few years back, when my previous employer bought a high-end FLIR camera I was sent on a Infrared-Thermography course. We were taught that most IR light does not pass through glass, only near-IR. Based on that, would I be mistaken in thinking that it is a bit of a waste using specialized IR cameras with conventional lenses? Wouldn't the glass likely absorb a huge proportion of the incoming IR thereby nullifying the gains on the sensor side? Would these dedicated astro camera sensors be more suited to mirror-type telescopes?


The visible spectrum stretches from about 380nm to about 750nm. Standard glass will usually pass light from about 400nm to 900-950nm or so. Depending on the materials, various kinds of optical glass will pass more or less IR. Near Infrared stretches to around 1400nm. Most IR photography works in the MUCH nearer IR range, 750-900nm (not even as deeply as 900nm even), so I don't see why using standard lenses would be a problem. If you want to work deeper into the near IR spectrum, then you might need higher quality or different kinds of lenses.


Also remember that there are reflecting telescopes. With mirrors, any part of the electromagnetic spectrum that the mirror material is not transparent to will be reflected. Near IR imaging (which is sometimes done in astrophotography) is usually done with some kind of pure reflecting telescope, newtonians or RCs.

jrista

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Re: Deep Sky Astrophotography
« Reply #199 on: May 10, 2015, 02:54:11 AM »
I wrapped up the first draft of the design for my astrophotography site, Nascent in Nebulosity:



Honestly not sure when I'll have time to turn it into an actual web site, but overall, I'm happy with the progress on the design. Here is the landing screen and transition to site animations:

http://i.imgur.com/JqLAfVU.gif

The initial screen:




Schmave

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Re: Deep Sky Astrophotography
« Reply #200 on: May 12, 2015, 12:09:00 PM »
The website looks really good jrista!  Thanks for sharing.

East Wind Photography

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Re: Deep Sky Astrophotography
« Reply #201 on: May 12, 2015, 10:55:18 PM »
Yes I expect to see all of those cool tips for taking better astrophotos along with image processing techniques.  Hell maybe even a store front for pixinsight services.  We take the shots and pay for you to process for us.  :)


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Re: Deep Sky Astrophotography
« Reply #201 on: May 12, 2015, 10:55:18 PM »

jrista

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Re: Deep Sky Astrophotography
« Reply #202 on: May 16, 2015, 06:40:25 PM »
Hah, interesting idea about the PixInsight "storefront". I don't know that I'd ever have that much free time. It takes a lot of time to process an image. Also, processing is where each photographer's personal style comes out, and I wouldn't want to take that away from people.

I guess one thing I could offer is an integration service...just take their RAW files, darks, biases and flats, and integrate the data into .fits and .tiff files, then send em back. That's mostly just CPU time, and maybe an hour or two of my own time.

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Re: Deep Sky Astrophotography
« Reply #202 on: May 16, 2015, 06:40:25 PM »