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Mallincam Alternative-Digital

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#26 Vondragonnoggin

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Posted 08 May 2012 - 09:06 AM

Just to be clear here - the 14" SCT shot was 30 seconds, while the pic here in this thread from the 11" was 112 seconds. I think they are comparable. Since the 14" was single shot and no processing, it might qualify as a semi-live view.

They are both F/3.3 for the shots.

Amazing to think about what can be had in such short time.

#27 psu_13

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Posted 08 May 2012 - 09:20 AM

Here is a single 2min frame of M51 from a CCD camera that I took a couple of weeks ago.

http://www.flickr.co...tream/lightbox/

This is taken with a Celestron 8 inch running at F5. I did not do any processing on this picture except to set the black and white points and subtract a dark.

Here is a 2min Mallincam frame taken with the same telescope at the same focal length:

http://www.flickr.co...N00/7004785149/

This is a screen grab from the video feed.

I don't think there is a huge difference, except that my CCD camera is monochrome. :)

For live viewing the Mallincam *can* let you trade off shorter exposures for more noise by manipulating the gain. In addition there is no doubt that the "live" video feed is a more immediate experience than capturing CCD frames and then processing them into a real picture. IMHO those are the two main differences between the Mallincam and CCD experiences. One should not minimize them.

On the other hand, as excellent a tool as it is (I have a VSS+ and really like it) I think that claims about the mallincam being an order of magnitude more sensitive than comparable CCD cameras are probably a bit overblown. The real win in the video camera is that the immediate feed is an image that has already been processed into something that's nice to look at with no more work on your part.

You can imagine the existence of CCD still cameras that could work this way (like how digital SLRs generate JPEG files), but it probably won't happen because most users of CCD cameras are not really interested in that quick view workflow.

#28 Vondragonnoggin

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Posted 08 May 2012 - 09:25 AM

So, how long does it take to setthe black and white points and subtract the dark?

The mallincam 2 minute image is taking 2 minutes to appear on the monitor I'm assuming. How long to get the ccd image on your computer screen the way it is?

#29 psu_13

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Posted 08 May 2012 - 09:59 AM

Setting the black and white points can be done in real time. The dark frame stuff is post-processing that you don't do during capture. I should have found the actual raw frame, but this is the one I had.

#30 Vondragonnoggin

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Posted 08 May 2012 - 10:17 AM

Setting the black and white points can be done in real time. The dark frame stuff is post-processing that you don't do during capture. I should have found the actual raw frame, but this is the one I had.


Thanks for your examples. The ccd image appears much smoother than the mallincam capture, but there is more detail apparent in the mallincam capture - not by a lot though.

Very interesting comparison. Both your screen grab and Dwight's sho that amp glow in the corner. Does this appear on the monitor too?

To get back on the original topic - does anyone have an example from the original camera mentioned?

#31 psu_13

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Posted 08 May 2012 - 10:22 AM

Yeah. The read amplifier in the video camera runs all the time, so for longer exposures the amp glow is always apparent.

#32 Vondragonnoggin

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Posted 08 May 2012 - 10:47 AM

Finally, here is Nytecam's M51 60 second exposure - Scroll down a few posts

That's all the examples I'll post, but clearly the 14 seconds to 5 minutes comparison or even 112 seconds to 20 minutes guess are not at all what is shown by my examples.

I needed to post this because as I stated previously, after reading the posts by Chris and Dwight, I clearly thought you would need to do very long exposures to match what the very short exposures of the mallincam offered and I was a little dismayed by this. It did not seem accurate to me.

It appears that you can get quite a bit of detail from short exposure ccd capture too.

#33 mpgxsvcd

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Posted 08 May 2012 - 11:00 AM

Here are some straight out of the camera jpgs from the Panasonic GH2 and the Panasonic GF1. Both cameras are a couple of years old technology. The GF1 goes for less than $200 now.

This is a 2 minute and 8 second single unedited exposure from the GH2 using an AT8IN @ 800mm and F4.0. It used ISO 320 for this shot. It looks exactly like this on any LCD display at 1080p.

Attached Thumbnails

  • 5211912-P1110692_resize.jpg


#34 mpgxsvcd

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Posted 08 May 2012 - 11:31 AM

Here is an ISO 1600 60 second shot from the older GF1.

Attached Thumbnails

  • 5211957-P1710828_resize.jpg


#35 Chris A

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Posted 08 May 2012 - 11:55 AM

You must understand sorry perhaps you are new at this but you are talking a comparison between apples to oranges!! ** If you want to do live video observations of faint deep sky objects then buy a Mallincam on the other side if you want to do imaging and then process for pretty pictures for web display or wall hanging then buy a dedicated ccd camera. ** There is NO camera to do it all perfect the way we always want it to be **!! It is the same principle as telescopes meaning there is no one telecope to do it all!! :foreheadslap:

#36 psu_13

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Posted 08 May 2012 - 12:05 PM

I don't think the point of this thread is to make any sort of claim that the tools being compared are equivalent. There are certainly differences. But I think the comparison is still interesting.

#37 Stew57

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Posted 08 May 2012 - 12:07 PM

There is an update to envisage that runs on Win7. I have it running on my Win 7 x64.

#38 Vondragonnoggin

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Posted 08 May 2012 - 12:07 PM

You must understand sorry perhaps you are new at this but you are talking a comparison between apples to oranges!! ** If you want to do live video observations of faint deep sky objects then buy a Mallincam on the other side if you want to do imaging and then process for pretty pictures for web display or wall hanging then buy a dedicated ccd camera. ** There is NO camera to do it all perfect the way we always want it to be **!! It is the same principle as telescopes meaning there is no one telecope to do it all!! :foreheadslap:


Then why does the MC xtreme offer imaging and up to 100 minute exposure?

Also, what does that have to do with 14 second to 5 minute comparisons that are untrue?

:question:

#39 Stew57

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Posted 08 May 2012 - 12:15 PM

I have a meade dsi pro, meade dsi color, and mallincam. When using envisage with dark subtract but no stacking there is really no comparison with the mallincam. 5 minutes with either dsi is not nearly as good as the mallincam at 2 min. I have relegated the dis's to guiders. Now with stacking, and processing it is a different matter, but the whole idea of the mallincam was to cut out the amount of efffort and time. Just compare the 30 to 40 second ETX80 images to what you can realistically see visually in a larger scope and you will see where they get some of the numbers.

Sky quality makes a huge difference, so if the same scope is not shooting under the same sky, pictures can be quite misleading.

#40 Peter D.

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Posted 08 May 2012 - 12:35 PM

Mark,

How do you get an update to Envisage to run Win7; Meade? I thought they didn't support it any more.

Pete

#41 Chris A

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Posted 08 May 2012 - 12:37 PM

This is not a practical way to show this point 14 sec to 5 min comparison. One MUST use the same setup (scope and focal ratio, filters etc.), same weather conditions (compare them on the same night) and same location to make this a fair test.

Chris A

#42 Peter D.

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Posted 08 May 2012 - 12:44 PM

OK, I see it on the Meade website. :foreheadslap: I'll try it out as soon as the rain stops...next month? :bawling:

#43 mclewis1

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Posted 08 May 2012 - 12:59 PM

What Chris said ... :grin:

He's been through the side by side comparison issue as much as anyone.

It's really really difficult to do accurate and totally unbiased comparisons. Done properly it's the same scope with the same image train and f ratio (this is often difficult because different types of cameras have their sensors at different points which makes the focal reduction a bit different ... and here even a few mms can make a difference) with images taken just a few minutes apart. Highly accurate focusing at each step, meticulous note taking, and consistency in the exposure procedures any post processing is also very important.

It's always dangerous to read too much into these comparisons. You can get a general idea about differences when you compare two images taken on two different nights but that's about it.

#44 Chris A

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Posted 08 May 2012 - 01:03 PM

Eric this is what I really want to see before I agree & believe that a ccd/dslr camera can show in near real-time just like a Mallincam can show as far as detail and display timing goes. I want to see someone with their ccd or dslr go onto NSN and show us all some faint deep sky objects in near real-time! I do not know why someone has not joined NSN (it is free) and broadcast this using Manycam or WebcamMax in order to show us that this is possible? I believe Pete when he shows his images, however images shown at a later date can be manipulated too much with Phtotshop etc. I am glad that Pete mentioned that the ccd image was dark subtracted which makes a big difference in the final image even if it's only one light and not stacked. It would have been better to see the raw image in it's live form.

Chris A

#45 Vondragonnoggin

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Posted 08 May 2012 - 01:06 PM

This is not a practical way to show this point 14 sec to 5 min comparison. One MUST use the same setup (scope and focal ratio, filters etc.), same weather conditions (compare them on the same night) and same location to make this a fair test.

Chris A


So, you are saying you cannot make blanket statements about these comparisons? It is conditional?

#46 Vondragonnoggin

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Posted 08 May 2012 - 01:09 PM

Eric this is what I really want to see before I agree & believe that a ccd/dslr camera can show in near real-time just like a Mallincam can show as far as detail and display timing goes. I want to see someone with their ccd or dslr go onto NSN and show us all some faint deep sky objects in near real-time! I do not know why someone has not joined NSN (it is free) and broadcast this using Manycam or WebcamMax in order to show us that this is possible? I believe Pete when he shows his images, however images shown at a later date can be manipulated too much with Phtotshop etc. I am glad that Pete mentioned that the ccd image was dark subtracted which makes a big difference in the final image even if it's only one light and not stacked. It would have been better to see the raw image in it's live form.

Chris A


But we weren't talking about webcams. The comparison was 14 second mallincam to 5 minute ccd exposure.

I also posted several examples of 60 seconds and under. Some of them directly stated no processing.

#47 mpgxsvcd

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Posted 08 May 2012 - 01:09 PM

You must understand sorry perhaps you are new at this but you are talking a comparison between apples to oranges!! ** If you want to do live video observations of faint deep sky objects then buy a Mallincam on the other side if you want to do imaging and then process for pretty pictures for web display or wall hanging then buy a dedicated ccd camera. ** There is NO camera to do it all perfect the way we always want it to be **!! It is the same principle as telescopes meaning there is no one telecope to do it all!! :foreheadslap:


That is actually is the issue. This is Apples to Apples. I think a lot of the people on this forum simply think because cameras before couldn’t do good live viewing that the cameras of today can’t either.

The fact is simply that I use my camera in the exact same fashion as the Mallincam is used. I hook it up to a TV or monitor via a single Composite or HDMI connection. I spend 8 seconds to 4 minutes on each object that I want to see.

However, I can also use my camera to take stills, video, stacked images, or broadcast. I just happen to only be using it for live viewing without any editing at the moment.

In all honesty I am not trying to convince anyone to switch from the Mallincam. It is a great device for its intended purpose. However, I would like to know if Rock’s claims are accurate or not. I have my doubts but I would love to be wrong on this one.

I simply don’t believe that it has 5 stops better exposure than the camera I have unless you are talking about sensitivity to Hydrogen Alpha. Then it is simply that my camera has a filter and the Mallincam doesn’t.

Can someone post an 14 second picture of any object other than Orion’s Nebula(I can get that in 15 seconds on my camera) taken with the Mallincam? I just simply want to see a picture that proves Rock’s claims.

#48 mpgxsvcd

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Posted 08 May 2012 - 01:11 PM

What Chris said ... :grin:

He's been through the side by side comparison issue as much as anyone.

It's really really difficult to do accurate and totally unbiased comparisons. Done properly it's the same scope with the same image train and f ratio (this is often difficult because different types of cameras have their sensors at different points which makes the focal reduction a bit different ... and here even a few mms can make a difference) with images taken just a few minutes apart. Highly accurate focusing at each step, meticulous note taking, and consistency in the exposure procedures any post processing is also very important.

It's always dangerous to read too much into these comparisons. You can get a general idea about differences when you compare two images taken on two different nights but that's about it.


I don't care about a comparison. I just want to see real proof that it can take a picture of a reasonably dark object in 14 seconds. I haven't seen that yet.

#49 mpgxsvcd

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Posted 08 May 2012 - 01:19 PM

Eric this is what I really want to see before I agree & believe that a ccd/dslr camera can show in near real-time just like a Mallincam can show as far as detail and display timing goes. I want to see someone with their ccd or dslr go onto NSN and show us all some faint deep sky objects in near real-time! I do not know why someone has not joined NSN (it is free) and broadcast this using Manycam or WebcamMax in order to show us that this is possible? I believe Pete when he shows his images, however images shown at a later date can be manipulated too much with Phtotshop etc. I am glad that Pete mentioned that the ccd image was dark subtracted which makes a big difference in the final image even if it's only one light and not stacked. It would have been better to see the raw image in it's live form.

Chris A


Simply put it is a pain to drag the laptop out to the telescope in order to do the live transmission. There have already been arguments that one of the benefits of the Mallincam is that it doesn’t require a computer to view with it.

I can try to do this though. I just bought a laptop with USB 3.0 so I can do HD capture from my camera. Let me try to get one of the black magic devices and then I can do a broadcast.

Can you define what you consider faint objects to be? It seems like everyone's opinion varies on that. It would be best if you can point us to someone's broadcast of objects that are viewable now so we can try to replicate it.

#50 mclewis1

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Posted 08 May 2012 - 01:23 PM

Are you a member of the Yahoo Mallincam group? If not join up and browse the photo section.

Here for example are a series of 12 second exposures with a 6" f5 scope. Some faint fuzzies and a few show pieces. If you dropped the f speed down to around f3.5 then these images would approximate what 8 second exposures would show with the same scope under the same conditions.

You won't find too many collections of sub 10s shots posted as most folks want to show off their pictures in the best possible way ... so the exposures tend to more often be 14 or 28s (two exposure presets on the older Mallincams), or more.


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