[Leica] IMG: Testing SL For Milky Way Imaging

[Jim Nichols]

Bob, when I need to reduce the noise in images, I turn to Neat Image.  
It requires some experimentation, but works if the amount of reduction 
is kept to a low level.  I think there is a trial version still 
available.  I have used it as a stand alone tool, and currently have it 
as a plugin in Photoshop CC.

Jim Nichols
Tullahoma, TN USA

On 6/23/2017 11:14 AM, Robert Adler wrote:
> Hi Howard,
> Thank you for this workflow of yours. It's very helpful and much
> appreciated.
> I will send you the raw file using the 12,500 ISO. I'd be very curious if
> you have more luck removing the noise. I'm going to play with the DxO noise
> program today to see how that works. Noise can be the killer of an image:
> this one is borderline. The NIK Dfine is not working anymore for me and is
> discontinued. I'd love to remove noise in CC, but I don't really understand
> how to do it: hit and miss. This despite reading tons about it.
> Thanks again and appreciate your expertise.
> Best,
> Bob
>
>
> Bob Adler
> www.robertadlerphotography.com
> *"Capturing Light One Frame At A Time"*
>
> On Thu, Jun 22, 2017 at 8:49 AM, Howard L Ritter Jr <hlritter at twc.com>
> wrote:
>
>> That’s a very nice capture of the region towards the center of the Galaxy,
>> Bob. And even expanding the image on my screen, I don’t see any bothersome
>> noise. There’s virtually none in the dark regions of the hills, and the
>> mottling in the lake and the sky I think is primarily due to the
>> innumerable stars. In any case, the SL’s performance at ISO 12500 is
>> impressive. That region is my favorite binocular target, and now that I’ve
>> discovered how to nearly eliminate the effects of light pollution in my
>> suburban sky, and begun to do sky imaging, it will be a target for that as
>> well.
>>
>> I don’t recall whether you mentioned seeing them when I first posted them,
>> but I took some similar shots of the Southern Hemisphere Milky Way from
>> Australia in April. I took them with a Nikon D810A (the astrophotography
>> model with the less IR-restrictive sensor cover plate) and the Nikon
>> 14-24mm zoom at 14mm or the 24-85mm zoom at 50 or 85mm. The shots with the
>> zoom were done with the camera on a tracking device to avoid star trailing.
>> I used ISOs of 1600-6400.
>>
>> http://gallery.leica-users.org/v/hlritter/Gallery_001/ <
>> http://gallery.leica-users.org/v/hlritter/Gallery_001/>
>>
>> I stretched the histogram of my images in PS by moving the white-point
>> slider to brighten the stars and the black-point slider to darken the
>> background sky, then fiddled with both, plus the grey-point slider, to get
>> the effect I wanted. To get rid of vignetting, I also applied a flat-field
>> correction frame that I took in daylight with a couple of layers of white
>> T-shirt over the lens, and the camera aimed away from the sun at a sunlit
>> scene, and then converted to greyscale. I think my images as posted are a
>> bit hyper-real, but that’s a goal of photographing any celestial targets
>> other than the bright moon and planets. In any case, they carry the flavor
>> of the visual impact of seeing the Southern Milky Way and the Magellanic
>> Clouds, for the first time, from the deep darkness of rural Australia. The
>> left side of the region of the MW that I imaged adjoins on the right your
>> region of the MW at the dense star cloud in the center of your first image.
>> The very different orientation of the MW is what happens when your
>> viewpoint is rotated 65 degrees clockwise!
>>
>> Did you do any post-processing of these images? They have the look of raw
>> images to me. If so, I’d be interested to see what the result of a
>> histogram stretch might be. Would you mind sharing the raw file with me so
>> I can play a little? I’ve added a couple of the raw images to my album so
>> you can see the difference post-processing makes.
>>
>> It’s possible to see very short star trails by enlarging your images. The
>> rule of thumb is that they won’t be easily noticeable if the exposure time
>> is not more than 300 sec divided by the FL in mm, so your 20-sec exposures
>> at 24mm are pushing it. If you’re going to do much of this sort of thing, a
>> camera tracker can be had for about the price of 2 or 3 SL batteries… 😉
>> Some of my images were exposed for longer than the rule of 300, which is
>> possible when the region being imaged is well away from the celestial
>> equator, where the stars move fastest.
>>
>> (Pardon me if I’m telling you things you already know!)
>>
>> —howard
>>
>>
>>> On Jun 21, 2017, at 5:28 PM, Robert Adler <rgacpa at gmail.com> wrote:
>>>
>>> Last night I went up to Silver Lake in the Sierras. It's at about 7,800'
>>> elevation. I went to see how the SL with the SL24-90mm would work with
>>> Milky Way photography. The two images were taken at 12,500 ISO @ 24mm,
>>> f/2.8 with a 20second exposure. I shot from 10:30pm until 3:00am...
>>>
>>> Though there is a lot of noise, I don't find it distracting. The drama of
>>> the center of our galaxy seems to outweigh any noise issues. Please click
>>> on the image to make it larger to fit your screen:
>>>
>>> http://www.robertadlerphotography.com/p133735760/h8e052599#h8e052599
>>>
>>> I would appreciate others' opinions as to whether or not they find the
>>> noise distasteful or does it look more like film grain. The images were
>>> post processed in Capture 1.
>>>
>>> Thanks for any opinions in advance,
>>> Bob
>>>
>>>
>>> Bob Adler
>>> www.robertadlerphotography.com
>>> *"Capturing Light One Frame At A Time"*
>>>
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