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Samsung SCB-4000/2000 vs Canon T2i sensitivity

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#26 nytecam

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Posted 09 January 2013 - 04:32 AM

An impresive M31 via DSLR single shot Moromete :bow:

#27 Moromete

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Posted 09 January 2013 - 11:21 AM

Thank you Nytecam! We both know it's not so impressive when compared to others M31 shots. ;)

For me it really is impressive because I have no experience in astrophoto, I have no guiding camera, I have used a C11 on CG5-GT pier mounted (not even an EQ6/Atlas) and I don't do image stacking or dark frames because of lack of time and mood.
Oh and I don't take a laptop outside with me.
I would like to have a DSLR to do everything for me, including stacking and dark frame subtraction, and let me see the beauties in the sky with ease and fast.

Someday maybe I'll buy an autoguider but I don't know if it resumes the guiding process automatically after changing different GOTO targets during the night. I don't see myself to setup the autoguider every time I enter a new GOTO target in the hand controller. I'm more a visual observer.

#28 Moromete

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Posted 09 January 2013 - 12:38 PM

Is the following combination usable: SCT + Meade f/3.3 reducer + inexpensive 1.25" 0.5x reducer + Lntech300/Samsung SCB-2000?

#29 Dwight J

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Posted 09 January 2013 - 03:11 PM

Usable but not pretty. The combo of the two will exacerbate their faults like coma and vignetting. It would depend on your tolerance of these aberrations when viewing. I tried a cheaper 0.5X focal reducer in combo with a 6.3 focal reducer and found the amount of coma objectionable. I have had good luck using an older version of Meade's 3.3 reducer and a two inch extension tube (Teleview) to achieve even more reduction without too much aberration but the quality of them is variable and I just was lucky. They still work better than the 0.5X variety as coma, although present, is just the outer edge of the field. Check the images I have posted as I used this combo for all but the last ones where I tried out the Mallincam reducer (also an option but pricey).

#30 mclewis1

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Posted 09 January 2013 - 03:31 PM

I agree with Dwight, the f3.3 reducer on it's own would likely be my choice. I've also stacked different focal reducers and found that the f6.3 and one of the .5x 1.25" reducers can work but doesn't look particularly good at the edges. Different .5x reducers will produce different results as well. I've also tried a .5x 2" reducer with better results but the f3.3 reducer by itself is still my first choice.

With the f3.3 reducer you can use a 1.25" visual back and 1.25" nosepiece on the camera. It can also be useful to remove the external threads on 1.25" visual back to reduce the amount of spacing. With this reducer I prefer to use T thread spacers and a T - C mount adapter on the camera ... this makes for an all threaded robust connection.

http://agenaastro.co...le-adapter.html

#31 Moromete

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Posted 09 January 2013 - 04:02 PM

Thanks for your feedback guys.

I see you both have experience in stacking a 0.5x reducer after the f6.3 reducer and prefer the Meade f3.3 reducer instead of this combo because of less coma with an SCT.

But has anyone tried a 0.5x reducer after a Meade f3.3 reducer with an SCT and a CCTV?

#32 mclewis1

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Posted 09 January 2013 - 04:44 PM

It would be fun to try that combination. It will be very fast and therefore will have very steep light cone angles so filters may be a big problem and there will be severe light drop off (vignetting) at the edges. The in focus travel required to come to focus could be an issue too.

#33 mattflastro

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Posted 09 January 2013 - 08:57 PM

It would be fun to try that combination. It will be very fast and therefore will have very steep light cone angles so filters may be a big problem and there will be severe light drop off (vignetting) at the edges. The in focus travel required to come to focus could be an issue too.

I am using the Meade x.33 reducer on the scope combined with a x.05 1.25" redcuer on the camera (replaces the nose piece) . It's the only way to get all the field of view the SCT has , which is very narrow to begin with.

It's true that there's some vignetting and coma at the field edges but this tiny video cam ccd doesn't see that far to the edges .

A simple test is to remove just the camera from the setup , but with all reducers in place on the scope .
Place a white sheet of paper at the sensor plane (the distance from the x.5 reducer back where the camera ccd window should be .

You can easily see looking thru the paper what is the illuminated area and how is it vignetting especially f you use the full moon projected on the paper.

I found out I can get the maximum reduction with the Meade reducer threaded straight into the back of the scope , as close to the scope as possible . The farther the reducer is from the scope, the less reduction you get.

Based on some field of view measurements I get my 8" and 10" SCT's down to F2.2 to F2.3 .

I have an adjustable extension between the Meade reducer and the camera 1.25" reducer .

I rotate the scope focuser all the way to the end and back off one turn. Then slide in the camera and adjust the variable extension until I reach close to focus. I secure the variable extension to that exact size and from there on focus normally using the scope focuser (by moving the primary). No microfocusers attached, just the reducer straight onto the scope back.

I placed a 2" light pollution filter in front of the Meade reducer around Christmas due to horrendous Christmas lights throught my neighborhood .

Forget about coma . The image scale is about 6-8 arcsec/pixel anyway so you won't see only some bigger stars due to coma, you'll see all stars bigger due to the image scale.

#34 mclewis1

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Posted 10 January 2013 - 01:00 AM

And there's one additional point ...

Those of us with a Mallincam and SCB4000 cameras have the slightly larger 1/2" sensors, those with the 435/2000 and LnTech cameras have the slightly smaller 1/3" sensors. This makes a difference when your are evaluating the edge performance with various focal reducers. Those using the 1/3" sensors won't have as much to complain about.

#35 Moromete

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Posted 10 January 2013 - 06:45 AM

Excellent news mattflastro!

What do you say about this camera http://www.bavono.com/eng/BVO616S.html ?

It has Sony ExView HAD CCD II, Sense-Up x1024 and AGC user selectable up to 36db (unlike Lntech or Samsung).

Problem is I can't find someone to sell it around the world.
Maybe we should Aliexpress to put it on their website because they already sell Bavono products! What do you think?

#36 mattflastro

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Posted 10 January 2013 - 09:17 AM

Excellent news mattflastro!

What do you say about this camera http://www.bavono.com/eng/BVO616S.html ?

It has Sony ExView HAD CCD II, Sense-Up x1024 and AGC user selectable up to 36db (unlike Lntech or Samsung).

Problem is I can't find someone to sell it around the world.
Maybe we should Aliexpress to put it on their website because they already sell Bavono products! What do you think?

I downloaded the user manual for that camera and it doesn't say anywhere MANUAL GAIN or FIXED GAIN, only AGC OFF and ON .

From the sketchy info in that one page manual the only thing you can set manually is a maximum limit for the AGC , similar to the EFFIO-S and P camera DSP's from Sony . The same idea as in setting SENSE-UP to ON and selecting a max value . The camera does whatever it wants up to that value . You can't force it to use the maximum as a fixed value .

#37 mattflastro

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Posted 10 January 2013 - 09:28 AM

Excellent news mattflastro!

What do you say about this camera http://www.bavono.com/eng/BVO616S.html ?

It has Sony ExView HAD CCD II, Sense-Up x1024 and AGC user selectable up to 36db (unlike Lntech or Samsung).

Problem is I can't find someone to sell it around the world.
Maybe we should Aliexpress to put it on their website because they already sell Bavono products! What do you think?

I downloaded the user manual for that camera and it doesn't say anywhere MANUAL GAIN or AGC OFF or FIXED GAIN .

From the sketchy info in that one page manual the only thing you can set manually is a maximum limit for the AGC , similar to the EFFIO-S and P camera DSP's from Sony . The same idea as in setting SENSE-UP to ON and selecting a max value . The camera does whatever it wants up to that value . You can't force it to use the maximum as a fixed value .

I also forgot to mention that Sony Effio AGC goes up to 42dB , that's double the gain . Cameras that do only 36dB have a reason for it, and the reason is poor AFE performance . No sense in amplifying noise .Also, case looks plasticky . Maybe it's a good camera but cooling in a plastic enclosure will be problematic.

#38 Moromete

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Posted 10 January 2013 - 10:37 AM

Mattflastro I think you wrong this time regarding Bavono cctv Gain and enclosure. :jump:

Here is the manual http://www.bavono.co...Manual(eng).pdf .

In the tiny product manual/specifications says that AGC = Off~36dB(3dB unit). I think this means you can increase the gain in steps of 3dB up to 36dB. Regarding Sony Effio I agree with you.
Regarding camera's enclosure, in the tiny product manual/specifications says Shell Material = Metal, not plastic.
Isn't this better Lntech300's AGC which is kept on Off because isn't user adjustable in different steps like Bavono is?!

Now shoot and correct me if I'm wrong. ;)

#39 telfish

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Posted 10 January 2013 - 12:51 PM

The guy selling these assures me they are the camera you are after. Comes with a lens. Not as cheap as the $70 ones but is it really better? Looks like it has network capability!

Quote

"BVO616S OR BVO616W They are the same, looking forward to your reply.
lens3.5-8mm

zesan yi"

http://www.aliexpres...tra-WDR-Gun-...

#40 Moromete

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Posted 10 January 2013 - 01:00 PM

No, it's not the same product. Aliexpress sells model BVO616W (with Sense-Up only 512x) and we need BVO616S (with Sense-Up to 1024x and AGC user adjustable 3dB steps).

Yes, it seems to have a lens and a metal enclosure, not plastic.

#41 telfish

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Posted 10 January 2013 - 01:42 PM

These are the specs he is quoting me at the same price as the W model.

BVO616S

Ultra High Resolution Wide Dynamic Range Box Camera

Features

1/3" Sony Ex-view HAD CCD II Image Sensor
Digital Wide Dynamic Range
Horizontal resolution of up to 700 TVL
Sens-up X1024 & minimum illumination of 0.0001 lux
Built-in automatic IR cut filter
Day/night mode to enable 24 hour continuous surveillance
8 times digital zoom
48 zones motion detection
24 zones privacy masking
Intelligent 3D DNR for reducing HDD capacity
Built-in OSD
Built-in balun
Supports dual power supply: DC 10V - 40V / AC 7V - 40V
Specifications

Model BVO616S
Video Standard NTSC PAL
Image Sensor SONY 1/3" Ex-view HAD CCD II
Total Picture Elements 1020(H) X 508(V) 1020(H) X 596(V)
Effective Picture Elements 976(H) X 494(V) 976(H) X 582(V)
Horizontal Resolution 700 TVL
Min. illumination (approx.) Color:0.1 Lux@F1.2(50IRE) / 0.0001 Lux(Sens Up On)
B/W:0.08Lux@F1.2(50IRE) / 0.00008 Lux(Sens Up On)
Synchronizing System Internal, AC Line Lock
Video S/N Ratio 52dB
Digital Zoom 8X
Day / Night AUTO / DAY / NIGHT / EXT1 / EXT2
High Speed Shutter 1/60(1/50) ~ 1/15K
Flickerless Mode ON / OFF
Digital Wide Dynamic Range OFF / HIGH / MID / LOW
Auto Gain Control (AGC) Off ~ 36dB (3dB Unit)
IR-Cut Filter Built-in
Iris ALC(DC Auto Iris) / ELC(Off/On ( ~ 1/200K sec))
Sens-up X 1,024
Smart IR OFF / ON
White Balance ATW1 / ATW2 / AWC / MANUAL / INDOOR / OUTDOOR
Digital Noise Reduction (2D+3D) HIGH / MID / LOW
Camera ID OFF / ON (Max. 20 char per line)
Motion Detection 48 Zones
Privacy Masking 24 Zones
Backlight Compensation (BLC) OFF / BLC / HLC
Options DIS, PAN/TILT
Video Output VBS 1.0V p-p (75ohm Terminated)
Fast Connection Built-in Balun
OSD Language English / Simplified Chinese / French / Portuguese / Spanish / Japanese / German / Russian
Power Input DC 10V - 40V / AC 7V - 40V
Power Consumption Less than 1.5W
Operating Temperature ‐10°C ~ +50°C
Operating Humidity Less than 90%
Shell Material Metal
Dimensions (mm) 107 x 61 x 55
Gross Weight (g) 531

#42 Moromete

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Posted 10 January 2013 - 02:22 PM

Make me understand please. He is selling both models or he says W model he sells is identical to S model which isn't on Aliexpress?

#43 telfish

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Posted 10 January 2013 - 02:30 PM

Yep,

He is saying that although the specs he gave me are different the camera and price is the same!

Latest confirmation.

Dear terry
BVO616S $187
regards
zesan yi

So who is going to be brave enough to be the one brave enough to order one?


Terry

#44 Moromete

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Posted 10 January 2013 - 02:41 PM

Than why isn't BVO616S on Aliexpress website?

That's strange. I don't trust chinese.

#45 telfish

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Posted 10 January 2013 - 02:42 PM

And that is the mystery!

#46 Moromete

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Posted 10 January 2013 - 02:48 PM

Thx for info.

Tell him to put BVO616S on Aliexpressss website and than we'll order it. If he wants to sell it he has to make the ordering process clear and transparent for the customer. Push him to do it because he has an interesting product. Ask him if will remove the IR filter on request.

#47 telfish

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Posted 10 January 2013 - 03:35 PM

Will do.

#48 mattflastro

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Posted 11 January 2013 - 03:38 AM

Yep,

He is saying that although the specs he gave me are different the camera and price is the same!

Latest confirmation.

Dear terry
BVO616S $187
regards
zesan yi

So who is going to be brave enough to be the one brave enough to order one?


Terry

Guys,
Before jumping head first and buying sight unseen an unknown $200 camera, take a moment and reason a little:

- this camera has exactly the same specs as the Lntech and a million others .
- it does NOT have FIXED MANUAL GAIN .
- the manual clearly states AGC adjustable in steps of 3 dB . It doesn't say MGC in 3dB steps . For people not used with electronics specifications, this might sound the same as manual gain but it is not.
- AGC adjustable in steps of 3dB simply means YOU SET THE AUTOMATIC GAIN CONTROL LIMIT in 3dB increments . The camera is still doing AGC = AUTOMATIC GAIN CONTROL . The value you set is the maximum gain the AGC is allowed to use , starting from the lowest value that's possible in that camera. It doesn't do AGC within a 3dB window . An AGC confined to a 3dB window doesn't exist .
- in order for a camra to have manual gain control, the specification should say something like AGC = OFF/MANUAL/AGC STEPS of 3dB , or OFF/FIXED 3dB steps/AGC 3dB steps . This camera DOES NOT HAVE MANUAL GAIN CONTROL.
- in order for a camera to be usable for astro it needs other qualities as well, such as :
- adjustable GAMMA
- low noise circuits , especially AMP-GLOW elimination. Security video cams have ALL amp-glow as made by the factory .

Fortunately there is a very easy and simple way to tell if this camera is worth buying .
ASK THE VENDOR WHAT DSP is inside the camera. There aren't that many DSP makers and models on the market and their specs are available in much greater detail than a single page camera datasheet . Once you know the DSP model, we can find its user manual, see the details of the OSD menu and exactly what the camera does.
I would NEVER buy a camera without knowing what DSP in used in it .

Good luck with your camera buy and please report back if the camera lived up to your expectations of manual gain.

#49 Moromete

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Posted 11 January 2013 - 05:33 AM

Damn it, you must be right again! :foreheadslap:

Your technical explanation seems logical.

I thought I was right because in the tabel from here http://www.aliexpres...WDR-Gun-Box-... says AGC = Level Setting.
Than I saw on Bavono's website that AGC is adjustable 3dB steps and I concluded that you set it manually with a fixed value.
I haven't thought that by level setting you establish only the upper limit and the AGC fluctuates as it wants between odB and user's fixed upper limit. :bawling:

#50 telfish

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Posted 11 January 2013 - 07:59 AM

Damn it, you must be right again! :foreheadslap:

Your technical explanation seems logical.

I thought I was right because in the tabel from here http://www.aliexpres...WDR-Gun-Box-... says AGC = Level Setting.
Than I saw on Bavono's website that AGC is adjustable 3dB steps and I concluded that you set it manually with a fixed value.
I haven't thought that by level setting you establish only the upper limit and the AGC fluctuates as it wants between odB and user's fixed upper limit. :bawling:


Oh well, if anyone still wishes to try it here is the buying link. I will ask him what DSP is in it just in case someone is interested.

http://www.aliexpres...e-Dynamic-Ra...






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