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Samsung SCB-4000/2000 vs Canon T2i sensitivity

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#51 Moromete

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Posted 11 January 2013 - 08:52 AM

Excellent job tellfish! Bravo! :applause:

If possible besides DSP, ask him the AGC is manual or works like mattflastro explained.

#52 Moromete

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Posted 14 January 2013 - 07:11 AM

What do you say about these models guys:

http://www.cameras-c...2012-manual.pdf

http://www.dahuasecu...-f781e--92.html

#53 mattflastro

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Posted 14 January 2013 - 09:38 AM

What do you say about these models guys:

http://www.cameras-c...2012-manual.pdf

http://www.dahuasecu...-f781e--92.html


The first one appears to still have only AGC , no manual settings. It also appears to have only x512 sens-up in auto mode, not manual. When you set sens-up to x512, the camera doesn't do 512 . It does what it decides in order to have the average image exposed the way it decides. The samsung or lntech are used by setting sens-up to off and setting exposure to slow shutter mode, user set value up to x1024 ( lntech ). This camera doesn't have a slow shutter manual setting .

The second camera has a Sony Effio-S DSP. I have such a camera and tested it a lot. I really wanted to make it work because the Sony name is a better guarantee of quality than Lntech for example. But the camera doesn't want to cooperate. The Effio DSP suffers from some excessive DSP processing that quickly saturates the bright areas of the image and makes it lose all color . Again, it's the DSP attempting to bring the whole screen average brightness to certain levels that may be useful for a surveillance video camera but it kills all color and washes out detail for astro. There is a slightly better version, Effio-P , which goes to x512 sens-up (the Effio-S only does x256 ) and due to the longer time , lower AGC can be used but it's still basically the same problem.

#54 Moromete

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Posted 14 January 2013 - 11:15 AM

I have read on forums that Dahua makes better quality products, as are in general Korean products than Chinese ones (at least that's my impression).

OK, than what about this one http://www.d-max.co....al/dcc-600f.pdf ?

D-MAX camera's AGC seems to be manual so maybe the cctv could be more useful at 512x with AGC On than Lntech at 1024x with AGC Off.

#55 mattflastro

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Posted 14 January 2013 - 11:28 AM

I have read on forums that Dahua makes better quality products, as are in general Korean products than Chinese ones (at least that's my impression).

OK, than what about this one http://www.d-max.co....al/dcc-600f.pdf ?

D-MAX camera's AGC seems to be manual so maybe the cctv could be more useful at 512x with AGC On than Lntech at 1024x with AGC Off.

I spoke with those guys about 2 months ago. The AGC is not manual , sens-up only to x512 . They use a little known Korean DSP K-600 or KC-600 (don't recall exactly off the top of my head). Feature set seems about the same as all the others.
As far as Lntech being Chinese, all I have to say is that I don't really know who makes what parts of those cameras. The DSP is designed by a Korean company . The vendors I dealt with when buying Lntech stuff are in Hong-Kong .The stuff I received from them came from Korea and Hong-Kong based on the waybills , customs declarations that were attached etc.

#56 Moromete

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Posted 14 January 2013 - 11:34 AM

Please help me understand. Look at page no. 13 in D-Max manual. Since you can set AGC at 0-255 that means AGC is still not manual?

#57 mattflastro

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Posted 14 January 2013 - 12:34 PM

Please help me understand. Look at page no. 13 in D-Max manual. Since you can set AGC at 0-255 that means AGC is still not manual?

AGC means automatc gain control and is not manual. The only difference between all the cameras you found is the number and size of steps that the upper limit of gain can be set by the user for the AGC . Typical AFE chips have programmable gains in the range of 36 to 46 dB in very small increments, as low as 0.1 dB and in some cases 0.015dB . That is roughly 300+ to 3000+ microsteps to set the AGC upper limit, so the DSP programmers decided to split this huge and useless number of steps into fewer larger ones , hence the low/mid/high variations , 0 to 100 or 0-255 . Please understand this, there is no more manual gain on current video surveillance cameras since the advent of onboard ARM based 32 bit DSP-s with OSD .

#58 Moromete

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Posted 14 January 2013 - 12:43 PM

Now I understood. Thank you for explaining. AGC myth busted! :)

#59 Moromete

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Posted 18 January 2013 - 02:27 AM

Does any Android application exist which allows the user to transform his Android device in a portable LiveView DVR for his CCTV/ analog astro camera by means of a USB cable connection?

#60 mattflastro

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Posted 18 January 2013 - 07:16 AM

Does any Android application exist which allows the user to transform his Android device in a portable LiveView DVR for his CCTV/ analog astro camera by means of a USB cable connection?

I don't know of any Android supported USB frame grabber .
However, there are other devices that record analog video on Flash memory cards.

#61 Moromete

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Posted 18 January 2013 - 10:06 AM

Yes, I know there are other devices. I have found a mini DVR with a 3.5" LCD an AV IN.
But it would be wonderful and cost effective to be able to connect everything in astronomy to your phone (Android or iPhone) and not to be forced to buy new devices for different applications in astronomy.
In other words I'm looking for a laptop substitute in my Android phone considering it has GPS,etc.

Just imagine a Lntech300 camera connected to your phone through a cable which replaces a TV and a separate recorder or a laptop or even become an autoguider. You have the phone all the time with you in your pocket.

Can CCTVs be used for autoguiding? Is any software available for this?

#62 mattflastro

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Posted 18 January 2013 - 11:31 AM

Yes, I know there are other devices. I have found a mini DVR with a 3.5" LCD an AV IN.
But it would be wonderful and cost effective to be able to connect everything in astronomy to your phone (Android or iPhone) and not to be forced to buy new devices for different applications in astronomy.
In other words I'm looking for a laptop substitute in my Android phone considering it has GPS,etc.

Just imagine a Lntech300 camera connected to your phone through a cable which replaces a TV and a separate recorder or a laptop or even become an autoguider. You have the phone all the time with you in your pocket.

Can CCTVs be used for autoguiding? Is any software available for this?

current Android phones are still far from capable of accomplishing what you envision . For one thing, the analog cameras need power that the phone can't supply. The USB frame grabber (no analog video input on Android phones) needs USB power too and I don't know of any phones that could support it . IF you want a real , reliable working solution, that's still in the hypothetical future . Maybe Ubuntu for smartphones will provide support for the type of stuff you want but not now.

#63 mclewis1

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Posted 18 January 2013 - 11:39 AM

Can CCTVs be used for autoguiding? Is any software available for this?

Yes. Because the video connection goes through a USB frame grabber you won't find support for specific video cameras in the autoguiding software ... but since the frame grabber creates a Windows web cam like video stream most autoguiding software can work with it.

The downside is that on low end cameras there can be quite a few warm/hot pixels and quite a bit of background noise which makes autoguiding sometimes a bit tricky. The slight shift in video sync between frames also prevents these cameras from being used as very accurate autoguiders but over all they do work.

#64 ccs_hello

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Posted 19 January 2013 - 10:14 AM

Android OS natively does not have USB webcam device driver(s) built in, let along the very high bandwidth demanding (cheap) USB video dongle (need isochonous transfer at USB 2 high-speed mode). If you are an experienced XDA Developer, you might be able to build a custom kernel to support the former, but almost impossible to support the latter class.

For IOS, it's much harder since it's a closed OS.

I have used smart-device's "USB Host mode" to support low-bandwidth easy devices (USB microphonee and USB audio device). I also know how to inject power and did so in the connection (now every newer devices with latest OS version who support it) will require it (i.e., smart device will not supply power). <-- If you want to know more, read my CN post in Software forum here.

P.S. for video dongle, even a low-end PC made few years back (e.g., Intel low-end Pentium 4) won't support it well (hickups). A smartphone, after all, is a smartphone (portable device).

P.P.S. OFF (the original) TOPIC discussions should start a new thread!!!

Clear Skies!

ccs_hello

#65 mattflastro

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Posted 19 January 2013 - 09:57 PM

Yes, I know there are other devices. I have found a mini DVR with a 3.5" LCD an AV IN.
But it would be wonderful and cost effective to be able to connect everything in astronomy to your phone (Android or iPhone) and not to be forced to buy new devices for different applications in astronomy.
In other words I'm looking for a laptop substitute in my Android phone considering it has GPS,etc.

Just imagine a Lntech300 camera connected to your phone through a cable which replaces a TV and a separate recorder or a laptop or even become an autoguider. You have the phone all the time with you in your pocket.

Can CCTVs be used for autoguiding? Is any software available for this?

you could control your Canon DSLR with your Android phone assuming it's a recent phone and you would have live-view and remote focus with it together with all other camera functions :

http://dslrcontroller.com/






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