alexisgreat
Veteran Member
Getting my camera modified so it can do things like this:
I found this wonderful thread posted on CN about the Panny GH3 and the Oly E-PM2. Seems like shutter shock is not much of a problem for astro.
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/
Here are some sample out of camera JPGs from both cameras. Most of these were taken with a 1.25” Baader UHCs filter. Some of them are actually at ISO 12,800. The Olympus applies just enough noise reduction to those images to make them usable.
Enjoy!
Rosette Nebula ISO 12,800 50 Seconds UHC-S filter 800mm F4.0 Olympus E-PM2
Rosette Nebula ISO 12,800 30 seconds
Horse Head 40 Seconds ISO 12,800 UHC-S filter Olympus E-PM2
Horse Head 1 Minute 7nm Ha Filter ISO 12,800
Super Nova ISO 1600 1 minute in 2x lossless crop mode for an effective focal length of 1600mm
Olympus E-PM2 M42 13 Seconds ISO 6400 single exposure no HDR
Panasonic GH3 30 Seconds ISO 6400 single exposure no HDR
M42 and Running man Olympus E-PM2 30 seconds ISO 12,800 single exposure no HDR UHC-S Filter
All Olympus cameras since the E-PM2 have had live bulb and live time. This feature is exactly what the Mallincam does. It allows you to set the refresh rate of the live view while the image is being captured. For instance if I take a 2 minute exposure I can have the camera refresh every 15 seconds and show me what it has captured so far.
Not sure about what he said here on page 2 about the E-PM2 doing true electrical gain all the way to ISO 25,600 however since it seems anything above ISO 5000 is "extended"
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/page-2
I have an Astro Tech 8 inch 800mm F4.0 scope with the Astro Tech coma corrector/field flattener. It has a 2 inch to t-mount adapter ring that came with the coma corrector. I put enough t-ring spacers in there to give me exactly 1 and 7/8 of an inch spacing between the shoulder of the t-mount adapter to the flange of the camera lens housing. If you need the exact dimensions of the spacers I can try to provide them later.
Then I use a thin t-mount adapter to micro four thirds adapter that I got off amazon for about $30 to attach the camera.
That is the setup I use when I am at a dark site. I don’t need filters there so I can just attach directly to the coma corrector. This gives me the least amount of coma and simplifies the collimation process.
When I image in my backyard I put the Orion 5 slot 1.25 inch filter wheel set in the imaging chain instead of the t-mount spacers. I have to adjust the total distance back a bit because the filters do affect the coma some.
I use 5 Baader filters including the UV/IR cut, UHC-S, OIII, 7nm Ha, and 30 nm Ha. Since I had Brent Oliver modify the E-PM2 to visible + Ha it works very well with all of the filters.
The GH3 and the Olympus cameras can be controlled by the Pixel wireless remote timer. There is no way to currently control the cameras by hooking them up to a computer with a wire. However, there is a program in development that will allow remote control of the GH3 via a wireless network. I have not tried that yet since I personally like the remote controls better. I hate bringing a laptop out there with me. It causes too much light pollution, the battery doesn’t last long enough, and it is just cumbersome to deal with.
I don’t guide normally. Since I have a fast F4.0 scope I can just take higher ISO images in 1 minute or less. The GH3 is only good for ISO 6400 and below since everything above that is not a true electrical gain. The new GH4 will go to at least ISO 12800 with a true electrical gain. However, that camera will be almost $1700. I will probably get mine late next month.
The GH3 will transmit the live view via wireless with a slight(1-2 second delay). The live view is good up to 8 second exposures. You can trigger the camera with a phone or ipad including in bulb mode. However, you can’t explicitly define what duration you are going to use with the wireless connection. I still use my wireless remote even when I am using the phone or Ipad for my live view.
The Olympus E-PM2 will do a true electrical gain all the way to ISO 25,600. I usually only use as much as ISO 12,800 though. 1 minute at ISO 12,800 with an F4.0 scope is a TON of exposure. You will blow out most bright objects with that exposure. From my testing ISO 12,800 is the equivalent of what the Mallincams I have tried will do. Canon A-PSC cameras cannot go above ISO 1600 effectively so that is why most people think you can’t use an interchangeable lens camera for near real time viewing.
I don’t get any vignetting and minimal coma when I don’t use the filters. I couldn’t afford the 2” filters so I do get a little vignetting when I use the 1.25” filters. I have tried aggressive(.5x) focal reducers and they produce massive coma with micro four thirds. That is one advantage a smaller chip camera like the Mallincams have.
That is much as I can say about it right now. The GH3 is a great camera for this. I just wish I could afford to have mine modified. That really does make a huge difference with a lot of great objects. I am excited for the GH4 though. It is supposed to have much better heat dissipation than even the GH3 has.
this part here on page 3 explains why I can only see the brightest stars in the LCD during preview
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/page-3
Panasonic cameras have a special mode called Shutter Preview on non-GHx cameras and it is called Constant Preview on the GH2, GH3, and GH4. I actually saw a sample of the GH4 menus and it is on there as well.
This special mode allows the Panasonic cameras to use an electronic rolling shutter with a shutter duration of 8 seconds or less in the live view mode. It will literally reduce the frame rate of the live view to 8 seconds per frame. There is no need to hit the shutter button at all with this feature. It can be engaged automatically on the GH cameras but you have to manually engage it on the other Panasonic cameras.
This mode will give you a preview of what the camera will see up to 8 seconds. It is absolutely essential for seeing these deep space objects in the live view and no other cameras except for Panasonic cameras have it. Not even a Mallincam can do this in pure live view mode.
The Olympus cameras will do what all other cameras do. They will only allow 1/30 of a second or less in live view. It is enough to see the brightest stars but nothing else. I have to either use the live time feature which continuously updates the display with what is captured so far or I just navigate using a bright star in the field of view. This is exactly what the Mallincam does.
Since I have both Panasonic and Olympus cameras I will usually navigate and align with the Panasonic camera and switch to the modified camera for imaging.
Here is what the Rosette Nebula looked like when you stack 5 of the 4 minute ISO 1600 exposures.
At the very end of the thread someone posted a graph about the E-PL5's transmission rate in different parts of the spectra- the hot mirror blocks about 65% of H-Alpha, I wonder if this is typical of other cameras too?
I measured transmittance of an e-pl5 hot mirror removed from my camera - in case anyone is interested in this information. it blocks around 65% of the h-alpha line normally.
http://www.cloudynights.com/index.php?app=core&module=attach§ion=attach&attach_id=624648
I found this wonderful thread posted on CN about the Panny GH3 and the Oly E-PM2. Seems like shutter shock is not much of a problem for astro.
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/
Here are some sample out of camera JPGs from both cameras. Most of these were taken with a 1.25” Baader UHCs filter. Some of them are actually at ISO 12,800. The Olympus applies just enough noise reduction to those images to make them usable.
Enjoy!
Rosette Nebula ISO 12,800 50 Seconds UHC-S filter 800mm F4.0 Olympus E-PM2
Rosette Nebula ISO 12,800 30 seconds
Horse Head 40 Seconds ISO 12,800 UHC-S filter Olympus E-PM2
Horse Head 1 Minute 7nm Ha Filter ISO 12,800
Super Nova ISO 1600 1 minute in 2x lossless crop mode for an effective focal length of 1600mm
Olympus E-PM2 M42 13 Seconds ISO 6400 single exposure no HDR
Panasonic GH3 30 Seconds ISO 6400 single exposure no HDR
M42 and Running man Olympus E-PM2 30 seconds ISO 12,800 single exposure no HDR UHC-S Filter
All Olympus cameras since the E-PM2 have had live bulb and live time. This feature is exactly what the Mallincam does. It allows you to set the refresh rate of the live view while the image is being captured. For instance if I take a 2 minute exposure I can have the camera refresh every 15 seconds and show me what it has captured so far.
Not sure about what he said here on page 2 about the E-PM2 doing true electrical gain all the way to ISO 25,600 however since it seems anything above ISO 5000 is "extended"
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/page-2
I have an Astro Tech 8 inch 800mm F4.0 scope with the Astro Tech coma corrector/field flattener. It has a 2 inch to t-mount adapter ring that came with the coma corrector. I put enough t-ring spacers in there to give me exactly 1 and 7/8 of an inch spacing between the shoulder of the t-mount adapter to the flange of the camera lens housing. If you need the exact dimensions of the spacers I can try to provide them later.
Then I use a thin t-mount adapter to micro four thirds adapter that I got off amazon for about $30 to attach the camera.
That is the setup I use when I am at a dark site. I don’t need filters there so I can just attach directly to the coma corrector. This gives me the least amount of coma and simplifies the collimation process.
When I image in my backyard I put the Orion 5 slot 1.25 inch filter wheel set in the imaging chain instead of the t-mount spacers. I have to adjust the total distance back a bit because the filters do affect the coma some.
I use 5 Baader filters including the UV/IR cut, UHC-S, OIII, 7nm Ha, and 30 nm Ha. Since I had Brent Oliver modify the E-PM2 to visible + Ha it works very well with all of the filters.
The GH3 and the Olympus cameras can be controlled by the Pixel wireless remote timer. There is no way to currently control the cameras by hooking them up to a computer with a wire. However, there is a program in development that will allow remote control of the GH3 via a wireless network. I have not tried that yet since I personally like the remote controls better. I hate bringing a laptop out there with me. It causes too much light pollution, the battery doesn’t last long enough, and it is just cumbersome to deal with.
I don’t guide normally. Since I have a fast F4.0 scope I can just take higher ISO images in 1 minute or less. The GH3 is only good for ISO 6400 and below since everything above that is not a true electrical gain. The new GH4 will go to at least ISO 12800 with a true electrical gain. However, that camera will be almost $1700. I will probably get mine late next month.
The GH3 will transmit the live view via wireless with a slight(1-2 second delay). The live view is good up to 8 second exposures. You can trigger the camera with a phone or ipad including in bulb mode. However, you can’t explicitly define what duration you are going to use with the wireless connection. I still use my wireless remote even when I am using the phone or Ipad for my live view.
The Olympus E-PM2 will do a true electrical gain all the way to ISO 25,600. I usually only use as much as ISO 12,800 though. 1 minute at ISO 12,800 with an F4.0 scope is a TON of exposure. You will blow out most bright objects with that exposure. From my testing ISO 12,800 is the equivalent of what the Mallincams I have tried will do. Canon A-PSC cameras cannot go above ISO 1600 effectively so that is why most people think you can’t use an interchangeable lens camera for near real time viewing.
I don’t get any vignetting and minimal coma when I don’t use the filters. I couldn’t afford the 2” filters so I do get a little vignetting when I use the 1.25” filters. I have tried aggressive(.5x) focal reducers and they produce massive coma with micro four thirds. That is one advantage a smaller chip camera like the Mallincams have.
That is much as I can say about it right now. The GH3 is a great camera for this. I just wish I could afford to have mine modified. That really does make a huge difference with a lot of great objects. I am excited for the GH4 though. It is supposed to have much better heat dissipation than even the GH3 has.
this part here on page 3 explains why I can only see the brightest stars in the LCD during preview
http://www.cloudynights.com/topic/451681-a-night-with-the-micro-four-thirds-cameras/page-3
Panasonic cameras have a special mode called Shutter Preview on non-GHx cameras and it is called Constant Preview on the GH2, GH3, and GH4. I actually saw a sample of the GH4 menus and it is on there as well.
This special mode allows the Panasonic cameras to use an electronic rolling shutter with a shutter duration of 8 seconds or less in the live view mode. It will literally reduce the frame rate of the live view to 8 seconds per frame. There is no need to hit the shutter button at all with this feature. It can be engaged automatically on the GH cameras but you have to manually engage it on the other Panasonic cameras.
This mode will give you a preview of what the camera will see up to 8 seconds. It is absolutely essential for seeing these deep space objects in the live view and no other cameras except for Panasonic cameras have it. Not even a Mallincam can do this in pure live view mode.
The Olympus cameras will do what all other cameras do. They will only allow 1/30 of a second or less in live view. It is enough to see the brightest stars but nothing else. I have to either use the live time feature which continuously updates the display with what is captured so far or I just navigate using a bright star in the field of view. This is exactly what the Mallincam does.
Since I have both Panasonic and Olympus cameras I will usually navigate and align with the Panasonic camera and switch to the modified camera for imaging.
Here is what the Rosette Nebula looked like when you stack 5 of the 4 minute ISO 1600 exposures.
At the very end of the thread someone posted a graph about the E-PL5's transmission rate in different parts of the spectra- the hot mirror blocks about 65% of H-Alpha, I wonder if this is typical of other cameras too?
I measured transmittance of an e-pl5 hot mirror removed from my camera - in case anyone is interested in this information. it blocks around 65% of the h-alpha line normally.
http://www.cloudynights.com/index.php?app=core&module=attach§ion=attach&attach_id=624648
