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Another (better!) Jupiter from ASI120MM cam-150%!

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#26 edsplace

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Posted 03 December 2012 - 09:19 PM

Yeah, I was just logging it to confirm my previous hypothesis about where the problem lie is now a theory. I found the problem myself, and can confirm you are correct! I see 65FPS. I am excited, hope to capture an image soon.

#27 Kokatha man

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Posted 03 December 2012 - 11:44 PM

Yeah, I was just logging it to confirm my previous hypothesis about where the problem lie is now a theory. I found the problem myself, and can confirm you are correct! I see 65FPS. I am excited, hope to capture an image soon.


Happy imaging - I put some values I used for these images' captures in this thread that you might like to work from.....what you will find is that the ASI120MM's small pixel size (3.75uM) creates a much greater image scale (something like 150% compared to a Flea3 etc..)

For the C14 I had to make a special adaptor (it is the part that that is "missing" in Sam's avatar where he displays this camera - the "plug" that holds the nosepiece.)

That way I could get my TeleVue 2X barlow right up against the sensor almost and reduce the amplification down to about 1.25X.....newtonians might be somewhat different there. :question:

#28 edsplace

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Posted 04 December 2012 - 12:31 AM

The camera I received came with a 1.25" adapter. I removed that "plug" using a hammer and screwdriver since I don't have a spanner tool. After that plug was removed any standard "C to 1.25" adapter should work. I imaged with a C11 tonight between clouds and in 20MPH winds... needless to say nothing even usable. I did come up with a barlow strategy. I used the element off 2"-2X barlow, then screwed that element into a 2"-1.25" adapter, I then put the filter wheel in that adapter with the camera in the filter wheel. It seemed to produce about an F20 size image from my experience.

On a side note a friend of mine a bit further south who ordered his ASI120mm camera when I ordered mine, who also owns a CPC1100 sent me some RGB stacks he acquired tonight, the seeing was great. I am very familiar with his equipment and imaging strategies. Below is the image I was able to produce using his data. Okay... without a doubt this camera is going to be an attractive upgrade/entry point product for many. 70fps in the red band down to around 50fps in the blue band, moderate gain for all channels. I noticed the color sensitivity seems much flatter than the Sony ICX618 chip. The rolling shutter was not an issue, there was no smearing even in the 20mph winds with the planet bouncing all over the place, no artifacts noticed in either of our first sets of images. The smaller pixel producing a larger image scale does allow you to image without a barlow if using a larger SCT (the image below was taken with a barlow.) Light weight is great for newtonian and dobsonian balance. I could just keep going.

Thank you Sam! and also thank you Kokatha for your assistance in getting my camera up and running quickly.

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#29 wenjha

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Posted 04 December 2012 - 02:26 AM

That's great first-light of jupter!thanks ED and Jule

#30 Kokatha man

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Posted 04 December 2012 - 02:34 AM

The camera I received came with a 1.25" adapter. I removed that "plug" using a hammer and screwdriver since I don't have a spanner tool. After that plug was removed any standard "C to 1.25" adapter should work. I imaged with a C11 tonight between clouds and in 20MPH winds... needless to say nothing even usable. I did come up with a barlow strategy. I used the element off 2"-2X barlow, then screwed that element into a 2"-1.25" adapter, I then put the filter wheel in that adapter with the camera in the filter wheel. It seemed to produce about an F20 size image from my experience.

On a side note a friend of mine a bit further south who ordered his ASI120mm camera when I ordered mine, who also owns a CPC1100 sent me some RGB stacks he acquired tonight, the seeing was great. I am very familiar with his equipment and imaging strategies. Below is the image I was able to produce using his data. Okay... without a doubt this camera is going to be an attractive upgrade/entry point product for many. 70fps in the red band down to around 50fps in the blue band, moderate gain for all channels. I noticed the color sensitivity seems much flatter than the Sony ICX618 chip. The rolling shutter was not an issue, there was no smearing even in the 20mph winds with the planet bouncing all over the place, no artifacts noticed in either of our first sets of images. The smaller pixel producing a larger image scale does allow you to image without a barlow if using a larger SCT (the image below was taken with a barlow.) Light weight is great for newtonian and dobsonian balance. I could just keep going.

Thank you Sam! and also thank you Kokatha for your assistance in getting my camera up and running quickly.


Crikey Ed - a hammer and screwdriver..!?! :shocked: :shocked: :shocked:

But I'm a bit mystified as to what you've done: that "plug" (my term btw) is the 40mm black anodized circular fitting (like a vey thick washer) that has a 40mm thread (M40) around its outside edge and a central threaded hole that already holds an 1&1/4" nosepiece as standard...in Sam's avatar both the plug & nosepiece are missing so that you can actually see the sensor...but you're correct, M40 is also known as "C" type which is a standard astro fitting.

I found that using it as it came meant the distance from the back of the barlow to the sensor gave too much amplification, even just unscrewing the barlow and only using the lens element to get things a bit closer to each other - so I did what I described getting a friend to lathe an adaptor.

Also, I run all the channels at the exact same framerate if I use the same exposures for each.....green is just as sensitive (actually a bit more) than red and gain is the only thing needed to be lifted for blue (like just about any mono cam.)

I'll put my "cheat sheet" values in this post - I refer to it when I change resolutions to know quickly what exposures I must set...

But it sure looks like your mate took some nice captures - and you've also done a very nice job of processing them Ed - congratulations to you both! :waytogo:

MONO COLOUR
RES EXP FPS EXP FPS
1280x960 30 30
1280x720 25 40
1280x600 22 45
1280x400 16.2 60
1024x768 12.5 40
1024x600 19.2 55
1024x400 12.5 80
800x800 25 40
800x640 20 50
800x512 16.3 60
800x400 12.5 80
800x320 10 100
640x560 16.2 60
640x480 14 70 30 32
512x440 13.7 74
512x400 12.5 80 25 40
480x320 10 100
320x240 7.6 130

#31 edsplace

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Posted 04 December 2012 - 10:37 AM

I don't want to discourage others about considering this camera because of the "plug" and barlow ect. So I made the graphic below to clarify how I set my camera up to be telescope ready. It's not difficult and required only 5 minuets time. I'll clarify the hammer and screw driver statement :-) At time I say fun thing for a reaction, that was one of them. I inserted a screw that fit tightly in one of the holes designed for the spanner tool, then I placed a flat head screwdrivers bit flush against the "plug" while resting on the screw, a gentle tap on the screwdrivers handle with a rubber mallet was enough to break the "plug" free, after that I used the screw as a tool to back the "plug" out of the camera body. I learned this trick years about working with optics and have yet to break anything. :smash:

Jule and I have "twin" setup. CPC1100's, same diagonal, same filter wheel, same filters, same cameras, same software. It's a little freaky and Keck twin-ish. When imaging often we are on the phone togther while imaging the same object, we are able to problem solve imaging issues together. This has worked great over the years.
Last night in my poor seeing I used your exposure tactic of increase the gain and keeping the exposure time at the lowest possible setting. I was hoping that in would get a few moments of clarity during this horrible seeing, and a quick exposure time would be the best way to take capture these. Unfortunately I had both low level and high level atmosphere turbulence and nothing usable was acquired. Jule had some of the best seeing every, claiming at one point that his video was better then processed images produced with the DMK21. I am fairly sure this was result a combination of the ASI120mm camera and seeing. Anyway with the good seeing the idea of low gain capture to keep noise to the lowest possible levels and increasing the exposure time while taking a small hit in frame rate was the best way to take advantage of these superb conditions. This is an advantage to the ZWO Design camera over TIS cameras. The variable frame rate allows you to increase exposure time without sacrificing much in frame rate. With TIS camera you may have to step down from 60FPS to 30FPS if you choose to increase exposure time while the the ZWO if was only a 15FPS hit. Just another advatage to this camera.

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#32 MvZ

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Posted 04 December 2012 - 11:29 AM

Weird, I could easily unscrew the plug and and lens in one go. Didn't even know there was a plug there, it acts like one single unit.

#33 Kokatha man

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Posted 04 December 2012 - 06:44 PM

Weird, I could easily unscrew the plug and and lens in one go. Didn't even know there was a plug there, it acts like one single unit.


Heh-hee Emil - I hope you realise that the nosepiece (the 4th of Ed's piks where he has his thumb on it) also unscrews from that "plug." :grin:

Actually it's easy to think that these parts are just one piece (lens & plug, n/piece & plug) but they're not.....the problem is, although they are "standard" threads Sam has had made for the cameras, "standard" isn't something a lot of AA accessories adhere to in many cases..! :mad:

You can easily use 1&1/4" GSO extension tubes etc that screw into the n/piece internal thread (or either plug's central thread) - the problem arises when you want to get the barlow closer to the sensor.....and that's not Sam or the camera's fault but rather the fact that there are so many non-standardised accessories going around!

You make a very good point with your comment I've quoted below Ed, one I've commented on myself but haven't articulated it as fully as in your quote:

Anyway with the good seeing the idea of low gain capture to keep noise to the lowest possible levels and increasing the exposure time while taking a small hit in frame rate was the best way to take advantage of these superb conditions. This is an advantage to the ZWO Design camera over TIS cameras. The variable frame rate allows you to increase exposure time without sacrificing much in frame rate. With TIS camera you may have to step down from 60FPS to 30FPS if you choose to increase exposure time while the the ZWO if was only a 15FPS hit. Just another advatage to this camera

Clear skies and happy imaging..! :waytogo:

#34 MvZ

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Posted 04 December 2012 - 06:57 PM

I didn't realize that Darryl. So far I have had no reason to 'grap a screwdriver and a hammer' and split these 'atoms'.

But next time I'll try and see if I can break them. Just because I can. Now I'm curious ;)

#35 Kokatha man

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Posted 04 December 2012 - 07:15 PM

.....the n/piece and its' plug really do look like one piece machining Emil and your impression was quite understandable.....perhaps I should comment (as a pro artist/designer) that Sam's Cams are very flash/sophisticated looking units..! :waytogo:

Screwing these on and off runs the risk of getting dust on the sensor if done in dubious conditions - I've had to clean the sensor twice (no big deal) but I'd recommend you wash your sledge hammer and monkey-wrench first..! :lol:

#36 Rankinstudio

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Posted 04 December 2012 - 10:43 PM

So it comes with the eyepiece adapter and a lens?

#37 edsplace

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Posted 04 December 2012 - 10:49 PM

Mine came with a wide angle lens, 1.25" telescope adapter, ~6' USB cable, and IR filter. The camera itself is also designed to fit into a 2" barrel without an adapter.

#38 Rankinstudio

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Posted 04 December 2012 - 11:00 PM

Thanks :)

#39 wenjha

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Posted 04 December 2012 - 11:13 PM

Hi Ed
May I use the picture in my websie?
I think its a good instruction for all users.
the "plug" actually is a universal CS lens adapter.
so you can use any CS lens to works with ASI camera.
I am going to use this setup(5mm-50mm lens) to capture meteor

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#40 wenjha

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Posted 04 December 2012 - 11:21 PM

here is a test of Orion at the focal length of 5mm
exposure 100ms gain 100 resized to half

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#41 edsplace

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Posted 04 December 2012 - 11:23 PM

Yes Sam feel free to use that image. I notices that was a CS adapter, but the threads it fits into are a C adapter. So when you get this camera is has fittings for C,CS,1.25" and 2"... That's Brilliant!

#42 wenjha

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Posted 04 December 2012 - 11:25 PM

here is a test of M42 area at the focal length of 50mm
exposure 100ms gain 100 resized to half

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#43 wenjha

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Posted 04 December 2012 - 11:27 PM

Yes Sam feel free to use that image. I notices that was a CS adapter, but the threads it fits into are a C adapter. So when you get this camera is has fittings for C,CS,1.25" and 2"... That's Brilliant!

Thanks Ed
Yes,its a multi function camera :grin:

#44 Kokatha man

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Posted 04 December 2012 - 11:35 PM

The camera itself is also designed to fit into a 2" barrel without an adapter.


:roflmao: :roflmao: :roflmao: That joke's on me Ed after my comments to Emil..!

I thought I'd canvassed all the permutations with camera fittings but that simple observation/utilisation escaped me - good one Ed!!! :waytogo:

I used a 2" & 1.6X Antares barlow (nice units) with the Flea3 and although I could employ it as you describe to go from my current 1.25X to about 1.6X, the same reasons I ditched the Antares would still be valid.....I didn't want a heavy barlow on the end of the filter wheel: my Televue lens element is after the EFW in the various configurations I can employ it as but its' weight is negligible.....

And folks might like to know that the ASI120MM is also proving itself a very amazing Deep Sky camera as well - talk about versatility..! :)

#45 Kokatha man

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Posted 04 December 2012 - 11:38 PM

Even more brillant - thanks for that extra info Sam..!!! :waytogo: :waytogo: :waytogo:

#46 karlo

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Posted 05 December 2012 - 04:49 AM

ought to be a great Lunar cam too !- I'm sold :)

#47 karlo

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Posted 05 December 2012 - 05:02 AM

don't tell the missus ;)

#48 ZuoZhao

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Posted 05 December 2012 - 05:53 AM

With TIS camera you may have to step down from 60FPS to 30FPS if you choose to increase exposure time while the the ZWO if was only a 15FPS hit. Just another advatage to this camera.

In fact,not exact, ED. 120MM not a 15FPS hit. It respond accurately to exposure time. If it not beyond speed limit. You just need choose the highest speed from menu. And then change exposure time. So you can get speed step by step. For example 20ms(50fps)-21ms(47.6fps)-22ms(45.4fps)-23ms(43.4fps)...

#49 DesertRat

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Posted 05 December 2012 - 04:55 PM

Darryl,
You write that the 'plug' or black anodized circular fitting in the ASI120MM is a standard M40 also known as "C" type. The "C" type is 1 inch 32tpi. From Sam's website it shows as a M42x0.75 T2 thread fitting. The older T mount (Praktica type) was a M42x1.

I think it would be possible to have an adapter made, or it may exist already, to adapt a removable 2" barlow nosepiece fitting to that. That would get you close, and if too close you might even add a T2 extension to use at the design magnification.

I've have not considered the effect of working too close to a barlow. It depends on the design of the barlow, but most current designs add a little bit of spherical undercorrection when used far away from design (like 3X for a 2X barlow). You also lose some color correction, which can be negated somewhat by refocussing for each color using a mono camera. Too close would also hurt color correction. A simple negative lens adds overcorrection, but modern barlows are usually 2-4 compound lenses, and a thought experiment is not helping me - best to test - or if you have the energy and time you could model - but manufacturers rarely release their designs!

This brings me to my real question. Does the ASI120MM support hardware (better than software) binning? If it does then one could use a higher power barlow in a more conventional way, imaging with 7.5u pixels at 640x480.

Glenn

#50 edsplace

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Posted 05 December 2012 - 06:40 PM

Glenn,
From what I see yes.






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