Astrophotography using a medium format camera

[JimKasson]

I suspect that people doing deep-space-object AP that have extra money for expensive cameras go for the purpose-built scientific grade ultrasensitive CCD cameras. Some of the "off the shelf" cameras can cost more than the new Fuji S/R plus one or two lenses.

I know a guy who builds research telescopes. His sensors are larger than what we call digital MF.

OTOH, one of the chip suppliers that he used to use, Fairchild, seems to have moved away from that end of the market.

Jim

 

[fcracer]

I took this handheld from inside a moving plane while coming down from an ambien high. Just imagine what this setup can do with a sharper aperture, a tripod, and less ambien!




GFX50R + VM 50MM F1.2 @ 1.2, 6400 ISO, ~3 seconds braced against the window



--
Fujifilm GFX50R review: https://fcracer.com/fujifilm-gfx-50r-first-impressions/
Medium format travel camera: https://fcracer.com/medium-format-travel-camera/
Travel and photography blog: https://fcracer.com

 

[Parag Shankar]

Thank you.

Best Wishes

 

[Parag Shankar]

Thank you

Best Wishes

 

[just Tony]

I find focusing on a point source difficult, especially a dim one. If I would you, I would find an easier-to-focus target at sufficient distance, and focus on that.

A Bahtinov mask is a great simplifier for focusing on stars. Use magnified live view. The principle makes good use of our visual system's "firmware" for detecting alignments.

https://en.wikipedia.org/wiki/Bahtinov_mask

A fair portion of the mask pattern needs to span the entrance pupil so a wide angle / small aperture lens would require a very small implementation of the mask.

--
Render unto Digital, that which is Digital's,
and unto Analog, that which is Analog's

 

[JimKasson]

I find focusing on a point source difficult, especially a dim one. If I would you, I would find an easier-to-focus target at sufficient distance, and focus on that.

A Bahtinov mask is a great simplifier for focusing on stars. Use magnified live view. The principle makes good use of our visual system's "firmware" for detecting alignments.

https://en.wikipedia.org/wiki/Bahtinov_mask

A fair portion of the mask pattern needs to span the entrance pupil so a wide angle / small aperture lens would require a very small implementation of the mask.

That is very cleaver.

 

[HB1969]

How you compare 50R with the above especially with the LCD Live View zoom magnification? My Canon zooms digitally the Live View by 10x.

The Pentax 645Z in Live View has 16x.

The GFX-50S has upto 16.7x magnification, I would assume that the GFX-50R has the same

FUJIFILM GFX 50S | Cameras | FUJIFILM X Series & GFX - Global

P

www.fujifilm.com

 

[Zoc]

I took this handheld from inside a moving plane while coming down from an ambien high. Just imagine what this setup can do with a sharper aperture, a tripod, and less ambien!


GFX50R + VM 50MM F1.2 @ 1.2, 6400 ISO, ~3 seconds braced against the window

--
Fujifilm GFX50R review: https://fcracer.com/fujifilm-gfx-50r-first-impressions/
Medium format travel camera: https://fcracer.com/medium-format-travel-camera/
Travel and photography blog: https://fcracer.com

This is really an astonishing image. What made you think of trying this?

 

[fcracer]

I took this handheld from inside a moving plane while coming down from an ambien high. Just imagine what this setup can do with a sharper aperture, a tripod, and less ambien!


GFX50R + VM 50MM F1.2 @ 1.2, 6400 ISO, ~3 seconds braced against the window

This is really an astonishing image. What made you think of trying this?

I always keep a camera on me, and I was lucky the GFX was in my carry on. It really was a bit surreal because I didn’t have my contact lenses on but could see there was something amazing when I looked out the window. I took 22 exposures until I got one with minimal motion blur, considering it’s hand held.

I am thinking about trying for the same flight again in the future to capture the same image but with some sort of stabilizing device so I can use a lower iso and a longer shutter speed. I’d say it was even more incredible when looking out the window.

--
Fujifilm GFX50R review: https://fcracer.com/fujifilm-gfx-50r-first-impressions/
Medium format travel camera: https://fcracer.com/medium-format-travel-camera/
Travel and photography blog: https://fcracer.com

 

[JimKasson]

I am thinking about trying for the same flight again in the future to capture the same image but with some sort of stabilizing device so I can use a lower iso and a longer shutter speed.

Good luck getting a gyro stabilizer through security...

 

[Zoc]

I always keep a camera on me, and I was lucky the GFX was in my carry on. It really was a bit surreal because I didn’t have my contact lenses on but could see there was something amazing when I looked out the window. I took 22 exposures until I got one with minimal motion blur, considering it’s hand held.

I am thinking about trying for the same flight again in the future to capture the same image but with some sort of stabilizing device so I can use a lower iso and a longer shutter speed. I’d say it was even more incredible when looking out the window.

 

[fcracer]

I always keep a camera on me, and I was lucky the GFX was in my carry on. It really was a bit surreal because I didn’t have my contact lenses on but could see there was something amazing when I looked out the window. I took 22 exposures until I got one with minimal motion blur, considering it’s hand held.

I am thinking about trying for the same flight again in the future to capture the same image but with some sort of stabilizing device so I can use a lower iso and a longer shutter speed. I’d say it was even more incredible when looking out the window.

 

[Zoc]

If you want some entertainment, there’s a long thread on the GFX group on Facebook. I was accused of the image being a fraud and so on.

I can see why the image inspired some strong responses! I have no trouble believing it's real. Kudos on it.

 

[KWNJr]

I took this handheld from inside a moving plane while coming down from an ambien high. Just imagine what this setup can do with a sharper aperture, a tripod, and less ambien!


GFX50R + VM 50MM F1.2 @ 1.2, 6400 ISO, ~3 seconds braced against the window

This is really an astonishing image. What made you think of trying this?

I always keep a camera on me, and I was lucky the GFX was in my carry on. It really was a bit surreal because I didn’t have my contact lenses on but could see there was something amazing when I looked out the window. I took 22 exposures until I got one with minimal motion blur, considering it’s hand held.

I am thinking about trying for the same flight again in the future to capture the same image but with some sort of stabilizing device so I can use a lower iso and a longer shutter speed. I’d say it was even more incredible when looking out the window.

You may want to get the GFX100S with IBIS

 

[Igor Sotelo]

Does it makes sense to use a 44mm x 33mm camera for AP? What telescopes are compatible with a Pentax 645z or Fuji GFX cameras?

 

[Doppler9000]

Does it makes sense to use a 44mm x 33mm camera for AP? What telescopes are compatible with a Pentax 645z or Fuji GFX cameras?

The Takahashi FSQ-106EDX4 f/5 Petzval will cover an 88mm circle.

The mount requirements go up in a rather non-linear way with regard to cost, as the weight of the equipment increases, so a bigger sensor creates a series of expensive requirements. It might be worth looking at dedicated astro cameras, as an alternative, if you don’t already have a 44x33 camera.

 

[Igor Sotelo]

Does it makes sense to use a 44mm x 33mm camera for AP? What telescopes are compatible with a Pentax 645z or Fuji GFX cameras?

The Takahashi FSQ-106EDX4 f/5 Petzval will cover an 88mm circle.

The mount requirements go up in a rather non-linear way with regard to cost, as the weight of the equipment increases, so a bigger sensor creates a series of expensive requirements. It might be worth looking at dedicated astro cameras, as an alternative, if you don’t already have a 44x33 camera.

Thanks for the information.

Was considering the Pentax 645z from time to time, though prices are still high. It seems that it may not be practical for AP.

What Astro cameras would you recommend?

 

[weihaowang]

Those interested in MF astrophotography can check my Astrobin gallery:
https://www.astrobin.com/users/whwang/
or my Flickr (link in the signature). There are many MF pictures, mostly by Pentax 645z, and a few (recent ones) by GFX 50R.

Brief summaries about the two cameras:

645z:

Pros: Best sensor performance I have seen with a pixel size that hits the sweet spot for astrophotography. Raw files are truly raw, "rawest" among all DSLRs I have ever used. No detectable raw cooking of any kinds. Get one while you still can, as Sony discontinued that sensor.

Cons: Huge flange-back distance. Because of this, lens adaption possibilities are very limited. Some telescopes that can cover the 44x33 sensor cannot accommodate 645z's large flange-back distance, which is really a pity. Native lenses are lousy in terms of corner sharpness (at least for the ones I tried). So despite the camera is extremely powerful, you don't have many choices for optics to go with the camera.

50R:

Pros: Outstanding lenses. They can easily outperforms Pentax 645 lenses when the GFX lenses are wide open and when the P645 lenses are substantially stopped down. This is a big factor for astrophotography. Allows about twice more H-alpha light to go through, comparing to camera of all other brands when not modified. Can be directly used on astrophotography without modification.

Cons: star eater. Faint and intermediate brightness stars are eaten by 50R's hot pixel suppression algorithm. It's not as bad as Sony's first-generation star eater on A7R and A7S, but still quite bad. Search for my report on this issue in the astrophotography forum. If you are a pixel peeper like I am, this is not a camera for you. You won't like the stars from this camera. Also, the sensitivity of this camera seems lower than 645z, although they should have identical sensors. It could be a stronger noise from 50R, or lower quantum efficiency. I can't say for sure. What's certain is that 50R is not as sensitive as 645z.

Regarding GFX 100(S), I had a chance to look at one 100's raw file taken by another astrophotographer. That person is quite skillful, and the image was sharply focused. I saw evidence of star eater on GFX 100 from that file, but it's not as bad as 50. Unfortunately, with just one picture, I can't make a definite conclusion. I am seriously attracted by the 100S. I hope some time this year I can borrow one from a dealer or a friend who owns one to bring the camera under real sky and test if it also suffers from star eater.

Cheers,

Wei-Hao

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https://www.flickr.com/photos/weihaowang/

 

[just Tony]

Does it makes sense to use a 44mm x 33mm camera for AP? What telescopes are compatible with a Pentax 645z or Fuji GFX cameras?

That moves you toward premium telescopes. The majority of available offerings cover 24x36mm or less, for example many of the popular and common Schmidt-Cassegrains.

Look for models with large internal diameters of the focuser assembly. Call this a "necessary but maybe not sufficient" specification. A number of years ago I was shooting with a Pentax 6x7 on an Astro Physics refractor that had a 2.7” focuser. There was some corner vignetting of course but people were happy at 6x4.5. They also had some models with 4” focusers for perfect 6x7 as well as circular coverage on sheet film. Field flatteners are often necessary with refractors. Many are available as optional accessories but in some cases they are permanent features.

One caution: Skywatcher's 150mm refractors have standard or optional 3" focusers but I would be wary about format coverage. The field curvature would be the downside for the down-spec Evostar (ED doublet objective), and with the focal reducer/field flattener there would be vignetting. Perhaps the top model Esprit would do well - ask in the astro forum.

Takahashi’s Epsilon series reflectors are designed for use with 120 roll film holders.

--
Wag more; bark less.

 

[isteveb]

Just curious but what tracker did you use. The weight of the camera and the lens is pretty hefty so I was wondering how you managed the tracking.