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Han Solo 2000

Imaging Guidance

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Hi All

After a number of months of inactivity, I've managed to get out with the scope and camera to play over Christmas. I managed to see the International Space Station using just my own eyes and also through the camera and managed to take a few basic shots! Was great to see it under great conditions. A combination of work and a horrible neighbour with a halogen floodlight permanently on at nights has frustrated my efforts. Plus, as ever, the weather! Its been pretty cold lately but some great nights with loads of stars so hoping to get some work in before real work again in the New Year!

I've decided, for the moment, to concentrate on the use of my Nikon D5100 with a tripod to see what images I can take and then process using stacking software. Was out early this morning (4am) and took some photos but couldn't seem to get anything to pickup on the camera. I'm basically in play mode with ISO settings, etc and was after a little guidance.

My camera is a Nikon D5100 and I have a Nikon AF-S Nikkor 18 - 300mm lens, an AF-S 28mm Prime Lens and the standard Nikon AF-S Nikkor 18 - 55mm lens that came with the camera. I am using the Prime lens for my early efforts.

I am playing around with ISO settings around 800 to 1200 and multiple exposures from 30 sec to 60 sec. Using Manual mode on the camera and a remote shutter control. 

I was wondering how good the pictures are likely to be when viewed immediately on the camera as a saved image or how much you just have to wait for in post processing and stacking? I want to ensure that I am getting good data and know roughly how good I should be able to see straight away.

Any guidance would be greatly appreciated. I want to play and get the hang of it before I take some trips out to somewhere much darker and away from annoying neighbours!

Thanks

Simon

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This is all about choosing the right celestial objects for the short exposures that make sense with a fixed tripod. Manually focusing on a bright star (or tonight, the Moon) prior to moving on to your chosen object is the best way to ensure that it is in focus. I would suggest that you use your standard Nikon AF-S Nikkor 18 - 55mm set at 18 and then stop the lens down (select an F number higher than the wide open lens) of F4 or F5.6, aim high up at the region around the Pleiades (M45) star cluster and take a whole load of 30 second exposures at an ISO setting of 1600 maximum. Use a cable release if you have one or the self timer if you don't so that you don't touch the camera to start the exposure.

This should yield some interesting results but you won't really see the fruits of your labours until you download the images onto your PC.

Good luck.

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Hi Simon. I have the same rig, but recently added an EQ mount and a 400mm prime (unfortunately a very soft lens). Here is one of my first images with 12-28mm @ 12mm 30 x10sec exposures ISO 1600, stacked in DSS with darks, flats and bias frames. Taken in May this year off a tripod. Post processing is the key to getting your data to show.

If you like a blue sky, set white balance to tungsten. I used the Nikon wireless remote for shutter.

I've seen other formulae, but for these cropped sensor bodies exposure time in seconds=400/FL seems to work well as a starting point.

Shoot in NEF/RAW.

--Jack

post-37593-0-66153900-1419840387_thumb.j

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Sorry Simon I have no useful info to offer as I'm also starting in AP but great info has been offered for the Nikon DSLR user (general info for all DSLR's). There's not as many of us like the Canon mob, but I knew you were out there :)

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Thanks Guys. Was cloudy last night so couldn't get out. I was a bit worried that I had gone for the wrong camera with the Canon seeming to be the favourite choice for most people.

Sure with some perseverance, I will get some great pictures. Lots of practise needed and thanks for the help.  :smiley:

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IMO you picked the better camera, if you don't mind putting a little extra "sweat equity " into it.

The dominance of Canons is due to their excellent support to astro imagers. Nikon has never made their base code public, while Canon has. This prevented the development of fine 3rd party software like BYEOS, for example. Both makers do not offer truly raw file saving, as they both twiddle with the data to some extent. In the case of Nikon, in an attempt to reduce noise, firmware often erased some faint stars. Black point clipping was also included, which narrowed dynamic range and further chopped off fine data. NEF was not truly lossless.

The developers of the great camera control software (BackyardEOS) which Canon users have loved has now been developed  Nikon users. It is offered currently as a free trial (BackyardNikon), as it is in beta test. I started with it in beta 1C and it is now in 2H. I have had no problems with it, and would be lost without it.

The Nikonhacker group has developed a number of firmware mods for various Nikon models. These make significant improvements. I selected a package which makes NEF truly lossless, allows use of generic batteries, eliminates the faint star killer, and removes black point clipping. The latter providing a big increase in dynamic range and decrease in image noise. I found the firmware upgrade to be easy and reversible.

The Nikon-Sony EXMOR sensor on the D5100 and D7000 has lower read noise  and is slightly larger than the crop sensor Canons. If one takes advantage of the above software and firmware improvements, I believe a superior astro camera is the result.

Don't judge the above by the quality of my images. These improvements are free, but quality gear is not.

Clear Skies! --Jack

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Hi All

I was wondering how good the pictures are likely to be when viewed immediately on the camera as a saved image or how much you just have to wait for in post processing and stacking? I want to ensure that I am getting good data and know roughly how good I should be able to see straight away.

Any guidance would be greatly appreciated. I want to play and get the hang of it before I take some trips out to somewhere much darker and away from annoying neighbours!

Thanks

Simon

This is roughly what you would see in the camera and after processing about an hours worth of 5minute subs.

BTW

My cam is the Canon 60Da and the exposures are 300secs ISO 1600 at f4 with 105mm lens.

Shorter exposures would no doubt show less but you can get an idea how 'bad' in camera images are compared with processed images.

Camera image

ic1805raw.jpg

Processed 12 subs

ic18052test.jpg

Edited by wxsatuser
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Thanks, good to see some raw images and post processed images. Gives me an idea of what I expect to see.

Many thanks for the help.

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BTW

All my images are taken with moderate LP and I use an Astronomik CLS clip filter.

The clip does over expose blue but is worth it for the longer exposures.

I normally expose for around 25 to 40% of the histogram which on most nights gives 300secs at around f4/iso1600.

On rare nights I have had 600secs exposures at f2.8/iso1600 but these are very rare.......4nights in a whole year. :sad:

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