Astroscope + DSLR = Gallery! (3 Viewers)

[cango]

Henry is back!
View attachment 476113
Our resident Hawfinch with a damaged left wing. Haven't seen him since early spring. Good to have him home.
Crappy light. E-30 at 400 ISO and 1/40 second.

Nice to have him back and being able to tell it's the same one

 

[DanC.Licks]

Definitely the same one. I checked the eye ring. It is like a fingerprint. We had a male, a female, and a juvenile female visit this spring, but the eye rings didn't match, and his wing was "better". Now we know for sure. Its Henry all right!

 

[kurakura]

Dan: the pic of henry looks very crisp and sharp... can only use bf f rom my phone atm, get some strange error on my comp, so cannot see ot that well

 

[DanC.Licks]

Well, actually it is far below par. The light was very bad, our window was dirty, and my E-30 does not perform very well in bad light. Check out post #667 from last year.
This is what a €400 80/600 doublet can do on a D7000 body.

 

[Tord]

Not liking the weather very much.
View attachment 474567

Incidentally I had a couple of Collarded Doves visiting my garden the other day, the first ones for quite some time. (Widespread species worldwide, but redlisted here). I was testing some E-M5 features, playing with the magnification zone, not really prepared and did not realize the subject was cropped...

 

[Tord]

Well, actually it is far below par. The light was very bad, our window was dirty, and my E-30 does not perform very well in bad light. Check out post #667 from last year.
This is what a €400 80/600 doublet can do on a D7000 body.
View attachment 476270

This one is really good, focus spot on and great colors.

 

[DanC.Licks]

Thanks, Tord.
That one was a real thrill because it was so unexpected. First the male showed up, then the next day the female, then Junior! Was lucky to have some sunlight reflecting back from the south wall of our house.

Another from yesterday


Chomp, chomp, chomp.....

 

[roztoczol]

Adult female Goshawk feeding on chicken.
Shot at 2000mm focal length: Pentax K5, SW 80ED +1,7 TN and 2xTC stacked together, slightly cropped and resized.
I met this bird with prey catched in village nearby sitting just 120-150 m from road. Goshawk was hesitating- fly away or stay. After 5 minutes It took remainings of its prey into talons and escaped.
Rough-legged buzzard-one of individuals wintering over here.
SW80ED+ 1,7TN slightly cropped

 

[Tord]

Hard to believe you used 3.4X magnification, considering the IQ on the Goshawk!

 

[kurakura]

I am wondering if the resolution would not be better only with TN and crop...well will have to experiment when the telescope lands

 

[Paul Corfield]

I am wondering if the resolution would not be better only with TN and crop...well will have to experiment when the telescope lands

In my own extensive testing in the past you will generally get more detail by using one TN or TC and cropping. Depending on the camera, conditions etc, more noise may be visible from the cropping but resolution will likely be higher. Also using one TN or TC and moving it further away from the camera will quickly ramp up the magnification. Some combinations I tried were still very sharp, even up to 3 or 4 being stacked to get 7X mag. Shutter speeds suffer so much that you would never really use it in the field. It may be an option on newer cameras with better high ISO performance. I shall try some stuff out next year when I get a new camera.

Paul.

 

[kurakura]

I thought so Paul...

80/460+adapter+extender ordered... now its the waiting game

 

[punta]

Adult female Goshawk feeding on chicken.
Shot at 2000mm focal length: Pentax K5, SW 80ED +1,7 TN and 2xTC stacked together, slightly cropped and resized.
I met this bird with prey catched in village nearby sitting just 120-150 m from road. Goshawk was hesitating- fly away or stay. After 5 minutes It took remainings of its prey into talons and escaped.
Rough-legged buzzard-one of individuals wintering over here.
SW80ED+ 1,7TN slightly cropped

I am well impressed with the Goshawk at that range :t:

 

[JGobeil]

Hard to believe you used 3.4X magnification, considering the IQ on the Goshawk!

It looks more like 3264mm or 65X to me + the crop on the photo itself.
(600mm scope) x (1.7X TN) x (2X TC) x (1.6X sensor crop factor)

 

[roztoczol]

I am wondering if the resolution would not be better only with TN and crop...well will have to experiment when the telescope lands

In theory diffraction limit for APS-C 16Mpx sensor is at ~7 aperture ( depending on wave length), but in practice SW80 ED with 1,7 TN ( aperture 12,5 ) gives better reach. I stack 1,7 TN and 2x TC only for video- goshawk was so cooperative, air was very clear and light nice - an I was able to try different combination. In normal condition such stacking is useless due to high ISO noise and camera vibrations/air turbulence.

Another member of Accipiter family female Sparrowhawk perching on a tree 60 m from my garden.K-5, tripod, ISO=640, 1/400s , 1000 mm . Original frame cropped to 50% linear size, denoised in NeatImage- exif is gone.

 

[cango]

Another member of Accipiter family female Sparrowhawk perching on a tree 60 m from my garden.K-5, tripod, ISO=640, 1/400s , 1000 mm . Original frame cropped to 50% linear size, denoised in NeatImage- exif is gone.

very nice details for the range. thanks for sharing.

 

[Tord]

In theory diffraction limit for APS-C 16Mpx sensor is at ~7 aperture ( depending on wave length), but in practice SW80 ED with 1,7 TN ( aperture 12,5 ) gives better reach. I stack 1,7 TN and 2x TC only for video- goshawk was so cooperative, air was very clear and light nice - an I was able to try different combination. In normal condition such stacking is useless due to high ISO noise and camera vibrations/air turbulence.

Another member of Accipiter family female Sparrowhawk perching on a tree 60 m from my garden.K-5, tripod, ISO=640, 1/400s , 1000 mm . Original frame cropped to 50% linear size, denoised in NeatImage- exif is gone.

Interesting, I am interested in understanding more about this diffraction limit and how it relates to the sensor pixel density. Do you have a pointer you can share?

The Sparrowhawk has an excellent amount of detail.

 

[roztoczol]

Interesting, I am interested in understanding more about this diffraction limit and how it relates to the sensor pixel density. Do you have a pointer you can share?

Most comprehensive tutorial, registration is required
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

Another examples:
http://www.luminous-landscape.com/tutorials/understanding-series/u-diffraction.shtml

http://www.dpreview.com/forums/thread/3025160#forum-post-38776453

 

[DanC.Licks]

http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

Didn't need to register.

 

[Tord]

Interesting, thanks for sharing. Did not needed to register rather.