Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Electronically Assisted Astronomy

Pages: 1 | 2 | 3 | 4 | (show all)
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Which camera? new [Re: jambi99]
      #5682320 - 02/15/13 08:47 PM

Quote:

Whats wrong with the netbook\laptop?




Not everybody wants to bring a computer in the field, and the Xtreme is simply _more sensitive_. Have you used a Mallincam?


Post Extras: Print Post   Remind Me!   Notify Moderator  
jambi99
sage


Reged: 08/14/10

Loc: Québec, Canada
Re: Which camera? new [Re: Dwight J]
      #5682522 - 02/15/13 10:52 PM

I just bought a used StarShoot II for 250$. The camera is cooled(-20 C) and has the ICX428 color sensor. The mammut is also cooled(-20 C). The Lodestar-c and the DSI are not, however stacking would solve that problem. Judging by Nytecame images(he has the Lodestar-C, noise it doesn't to be problem.I think cooling is a plus, but for exposure around 60s its mostly trivial...

Post Extras: Print Post   Remind Me!   Notify Moderator  
jambi99
sage


Reged: 08/14/10

Loc: Québec, Canada
Re: Which camera? new [Re: rmollise]
      #5682562 - 02/15/13 11:13 PM

Why the mallincam would be more sensitive ? What are the arguments about such statement? The mallincam use the same ccd. This mean that it has the same QE. QE is the bottle neck of any ccd camera. You can't produce photon that are not detected by the senor. Of course you can raise the gain, but that will never make your camera more sensitive. It will only make your camera look like it is more sensitive.You can also raise the gain up to saturation on these cameras.

I'm not bashing the Mallincam. I think they are really good camera. However, this is a forum and people come here for advices. I don't think that it is really fair give them the impression that there is only one option. There is other product that are more than capable of providing live view. This, at a much lower cost.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mattflastro
Vendor - Astrovideo Systems


Reged: 07/31/09

Loc: Brevard County , FL
Re: Which camera? new [Re: jambi99]
      #5682674 - 02/16/13 12:41 AM

Quote:

Why the mallincam would be more sensitive ? What are the arguments about such statement? The mallincam use the same ccd. This mean that it has the same QE. QE is the bottle neck of any ccd camera. You can't produce photon that are not detected by the senor. Of course you can raise the gain, but that will never make your camera more sensitive. It will only make your camera look like it is more sensitive.You can also raise the gain up to saturation on these cameras.

I'm not bashing the Mallincam. I think they are really good camera. However, this is a forum and people come here for advices. I don't think that it is really fair give them the impression that there is only one option. There is other product that are more than capable of providing live view. This, at a much lower cost.



That is correct, can't produce signal without photons .
However, different cams implement different design compromises .
Let's say you wanted the shortest integration time and were willing to sacrifice some othe aspects in order to get it.
Add a 10dB gain stage before the camera's normal AFE. Price you pay for this is lower dynamic range, lower singal to noise .
What you gain is 3 times higher "perceived sensitivity" . Can an imager live with the lower signal to noise ? PRobably not .
Can a video observer live with it ?
Yes, if the advantage is you only have to wait for 20 seconds for an image instead of 1 min (and the advantage gets multiplied by the fact that you may use a dob, that could track for 20 sec but not for a while whopping minute , or an altaz mount which would show too much field rotation in 1 min , or an eq mount with bad tracking or alignment ).
Add to this the horrendous pixel scale of 6-7 arcsec/pixel that most of these perceived very sensitive cams are using .
Can an imager live with such gross undersampling? Probably not . Imagers fret over 1.7FWHM seeing or mount tracking , use AO and guiding , etc. They don't want to use 7 arcsec/pixel.
Video astronomers like it to see stars the size of golfballs . This buys them shorter focal lengths and faster f ratios , which means a lot shorter exposures. Same camera, same gain, same S/N but double the pixel scale and you get 4 times the exposure .
Couple the 4 fold gained due to the pixel scale with the 3 times gained with the lower signal to noise due to higher gain and you have a camera that now can see in 30 seconds what it takes "less sensitive" imagers 6 minutes.
In theory all cameras with the same sensor model could have the same min/max gain adjustment (manual of course) and the same best signal to noise but due to many other issues, they don't. Up to this point it appears that very few have actually pushed for the shortest integration times even with degraded image quality . And the ones which are doing it use tricks such black clipping , look at the histograms of most of these great short exposure images . The black levels are clipped like with a chainsaw . Imagers don't do that unless they want to, but video gives no such choice . If you want to see it quick, you must live with the issues.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Which camera? new [Re: jambi99]
      #5682755 - 02/16/13 02:13 AM

Quote:

I just bought a used StarShoot II for 250$. The camera is cooled(-20 C) and has the ICX428 color sensor. The mammut is also cooled(-20 C). The Lodestar-c and the DSI are not, however stacking would solve that problem. Judging by Nytecame images(he has the Lodestar-C, noise it doesn't to be problem.I think cooling is a plus, but for exposure around 60s its mostly trivial...



I would be very careful suggesting that noise isn't a problem from Nytecam's image. Take a close look at what he said about the Hickson 50 image ...
Quote:

Your reference to Hickson 50 had me searching my images like below in 4m stack so could be difficult in only 60s exp which just recorded gxys A and B. My DSO gallery here but as you'll see, I use a regular CCD cam and not video cam - stellar penetration is similar and I get to see the images downloaded in realtime in brief exposures, but I have more control of finished results



It's a single stacked image from numerous subs, and stacking is a popular method of lower noise. The image is also somewhat processed ... the capture software is performing some video processing on the images (stretching and applying various filters). So to be clear that image is NOT representative of what you'll see as a "live view" from that camera.

Maurice gets some absolutely amazing images off of that camera/software combination (the best I've ever seen) but that little un cooled camera isn't quite in the same league as the cooled models or the video based Mallincams, particularly when using longer exposures (as he clearly states).

Cooling does start to benefit images at well under 60s exposures. It certainly helps those longer exposures but it's one of the main requirements for a continuous read video setup like in the Mallincams (who's sensor generates tons more heat at any exposure than the single exposure imaging cameras).


Post Extras: Print Post   Remind Me!   Notify Moderator  
nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: Which camera? new [Re: rmollise]
      #5682810 - 02/16/13 04:13 AM

Quote:

Yes. The Hicksons are easy with a Mallincam. And no computer frippery is required if you don't want it.


Rod - precious few examples [=images] of what the Mallincam can do on faint stuff on this forum beyond hearsay me thinks

Quote:

Maurice gets some absolutely amazing images off of that camera/software combination (the best I've ever seen) but that little un cooled camera isn't quite in the same league as the cooled models or the video based Mallincams, particularly when using longer exposures (as he clearly states).

Cooling does start to benefit images at well under 60s exposures. It certainly helps those longer exposures but it's one of the main requirements for a continuous read video setup like in the Mallincams (who's sensor generates tons more heat at any exposure than the single exposure imaging cameras). Mark


Mark - not convinced cooling is essential [for my 'cool' running Lodestar] at <60s exp [get saturation in <2m @ f/3.6] but removing my severe orange LP via software does take a hit on data. LP filters before cam [which I've tried] needs increased exposure so a no-win option.

What we need is a Mallincam v Lodestar/others unbiased head-to-head on same DSO, same exposure and similar scope but don't think, on this forum, unbiased is going to happen


Post Extras: Print Post   Remind Me!   Notify Moderator  
norden
sage


Reged: 09/08/08

Loc: Norden
Re: Which camera? new [Re: nytecam]
      #5682869 - 02/16/13 06:19 AM

Thanks for all the thoughtful responses! But remember I am a simple visual amateur without much knowledge of CCD cameras. I must say that I am interested in Orion G3. but can i use this camera with my CPC1100 telescope without a wedge? Can I take pictures of maximum 30-50 seconds without any problems? These are important questions for me. So should I buy a Mallincam VVS+ or Orion Star Shoot II. That is the question.

Edited by norden (02/16/13 07:15 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Which camera? new [Re: norden]
      #5682939 - 02/16/13 08:14 AM

The challenge with your telescope is that it has a very long focal length and most inexpensive cameras have a small chip giving a very small field of view. The G3 uses a Type 1/2 chip which is pretty small. A really neat option would be to mount the G3 on a small telescope riding piggyback on your CPC. I once built such a system with a little camera that used a Type 1/3 chip and a 35mm f/4 lens from a binoccular. This gave a field of view similar to the 6" f/5 Newtonian that I mounted it on. Another interesting option if you really wanted to mount a camera on your CPC would be a Canon DSLR and Backyard EOS. I wasn't a huge fan of using DSLRs for real-time observing, but things have greatly improved significantly after Canon released the XSi (450D) and Backyard EOS became available. The live view mode works well with bright objects like the moon and planets while the still frame mode gives you many options for deep sky. The large APS-C chip, high gain, and in-camera noise reduction would work well with you scope. I've been using a Canon T2i (550D) for over a year for both imaging and observing and I've really enjoyed it. The camera body only was $495 (I didn't need any lenses) which made it very economical as compared to some other options.

Food for thought...


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Which camera? new [Re: nytecam]
      #5682945 - 02/16/13 08:20 AM Attachment (23 downloads)

Quote:

Rod - precious few examples [=images] of what the Mallincam can do on faint stuff on this forum beyond hearsay me thinks




OK, if you don't feel inclined to take my word for it, or are worried I might be joshing or even fibbing, for god's sake, here's an image for you.

This was done with a Stellacam II at 10-seconds, and my Xtreme can easily best this. I just haven't been back to the Hickons.

Edited by rmollise (02/16/13 08:21 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Which camera? new [Re: nytecam]
      #5682956 - 02/16/13 08:32 AM

Quote:

Mark - not convinced cooling is essential [for my 'cool' running Lodestar] at <60s exp [get saturation in <2m @ f/3.6] but removing my severe orange LP via software does take a hit on data. LP filters before cam [which I've tried] needs increased exposure so a no-win option.

What we need is a Mallincam v Lodestar/others unbiased head-to-head on same DSO, same exposure and similar scope but don't think, on this forum, unbiased is going to happen



Maurice,

I agree, not essential but the cooling does make life a lot easier noise wise. Your work clearly shows the benefits of one alternative approach (stacking) to reducing image noise.

The physical filter issue is just one of the many realities of imaging. It's interesting that a number of Mallincam owners are pushing the exposure capabilities to enable some form of viewing under severely light polluted skies. Instead of 15-60s exposures they are going with multiple minutes. The filters are not the general LP type but rather very restrictive narrow band models. They of course now need good accurate tracking from their mounts but the results have been very surprising. The cameras are being worked very hard (and in a manner that Rock never originally designed them for but he has been gradually increasing this capability with each new model). In order to handle this more demanding type of viewing/imaging the cooling capabilities have been further improved (with the X2 model with it's improved cold finger and upgraded cooling control).

This is of course all very similar to the multiple filter narrow band imaging many folks with traditional imaging cameras are doing.

Yeah I'd also love to see some good well managed head to head comparisons.


Post Extras: Print Post   Remind Me!   Notify Moderator  
A. Viegas
Pooh-Bah
*****

Reged: 03/05/12

Loc: New York City/ CT
Re: Which camera? new [Re: mclewis1]
      #5683006 - 02/16/13 09:13 AM

Hickson 50 - on the Mallincam Website: Hickson 50

as the caption describes, SCT 10" 15 seconds. no processing whatsoever.

And here is another image, from this forum using 10" Newtonian and 56sec exposure, but under a full moon: Hickson50 under full moon

So... lets see the lodestar with same factors, 15 seconds and 56 seconds, no processing or tweaking.



Al


Post Extras: Print Post   Remind Me!   Notify Moderator  
ccs_hello
Postmaster
*****

Reged: 07/03/04

Re: Which camera? new [Re: Dwight J]
      #5683055 - 02/16/13 09:37 AM

Quote:

... The new Orion G3 camera ...



Please note that G3 when it first showed up in the market, the software isn't mature enough and got a few negative feedbacks. I think for "imaging", the situation has improved. For LiveView (it's part of the product description), there is no user feedback up to this day. So the result can go one way or the other.

Clear Skies!

ccs_hello


Post Extras: Print Post   Remind Me!   Notify Moderator  
ccs_hello
Postmaster
*****

Reged: 07/03/04

Re: Which camera? new [Re: A. Viegas]
      #5683088 - 02/16/13 09:56 AM

I do not recommend any head-to-head comparison that one side is a picture published in a website while the original picture publisher has not given the chance to defend himself, nor all info are disclosed.

We need scientifically provable/repeatable apple-to-apple comparison.
- under the same observation condition (LP and temperature)
- if using a filter, both have to use the same filter
- using the same OTA and same aux optics (e.g., focal reducer set at the same reduction ratio),
- document all camera parameters set (gain, exp time, gamma, etc.),
- present the data as original as possible. I.e. do not scale, do not process <-- if possible (some devices cannot defeat such settings), do as little compression as possible. Use astrobin or other sites to publish the data.

I.e., no details, no need to say mine is better than yours or even someone else' is better than another person's.
Adding non-scientifically quantified/qualified terms certainly is not helping. E.g., "million" times better. <-- is it an adjective or really means 10^6 (translated to 20 stops) better capability to gather photon flux .


P.S. Actually, in my own 0.02 view, I don't need any convincing. An extremely-high gain image system will definitely "see" more, so long as I can live with the noise level and spatial resolution.
Everything in life is a tradeoff.

P.S. the art of how to optimize these design parameters is well known (a few strategies and can be used in combination.) It's a matter that the astro-imaging/viewing market is so small that there aren't many players here. In that small market, majority of mfgs are concentrated in astro-imaging market and little on near-realtime view market. The situation changes a bit in recent days. Some began to re-purpose the imaging devices designed for one sector to the other (jack up the system gain and willing to tolerate low S/N), while the other side is building devices which can be dual-purposed (let smart brain - the computer software to do a better job, even possible in near-realtime.)
The world is turning and so should we.


Clear Skies!

ccs_hello


Post Extras: Print Post   Remind Me!   Notify Moderator  
jujumaster
member


Reged: 11/26/11

Re: Which camera? new [Re: mattflastro]
      #5683100 - 02/16/13 10:00 AM

Norden,
There is nifty little thing called a field de-rotator you can use for Alt-Az mounts. It looks a bit like a filter wheel and is a bit pricy, but it allows you to go beyond 60s. Rock Mallin uses it on his Alt-Az setup with great success.

Thanks,
Ian


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Which camera? [Re: ccs_hello]
      #5683105 - 02/16/13 10:03 AM

Quote:

I do not recommend any head-to-head comparison that one side is a picture published in a website.

We need scientifically provable/repeatable apple-to-apple comparison.




I ask again...have you actually USED a Mallincam or Stellacam? For one thing, while the video cameras can produce decent stills, their true forte is video images in near real time. If you don't like that, or think your DSI is better hooked to a computer, have fun.


Post Extras: Print Post   Remind Me!   Notify Moderator  
nytecam
Postmaster


Reged: 08/20/05

Loc: London UK
Re: Which camera? new [Re: ccs_hello]
      #5684645 - 02/17/13 05:19 AM Attachment (15 downloads)

Quote:

I do not recommend any head-to-head comparison that one side is a picture published in a website while the original picture publisher has not given the chance to defend himself, nor all info are disclosed. Clear Skies! ccs_hello


Exactly but unless one person/group uses the various camera[s] on same night and same equipment etc etc it ain't going to happen.

Below is my 0.02 with Hickson 50 in UMa from last night in 60s exp [sorry don't do video 56s!] via 12"SCT + SX Lodestar-C and ALL 5 gxys A-E recorded and annotated inset - not too bad for my LP London skies


Post Extras: Print Post   Remind Me!   Notify Moderator  
Stew57
Carpal Tunnel
*****

Reged: 05/03/09

Loc: Silsbee Texas
Re: Which camera? new [Re: nytecam]
      #5684836 - 02/17/13 09:31 AM

How do you get such dark looking sky at 60seconds? Both of my mallincams give a bright sky at anything over 40 seconds. Is there a filter for galaxies or some processing?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Dwight J
scholastic sledgehammer
*****

Reged: 05/14/09

Loc: Lethbridge, Alberta, Canada
Re: Which camera? new [Re: Stew57]
      #5685260 - 02/17/13 01:47 PM

It's called post processing.

Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: Which camera? new [Re: Stew57]
      #5685277 - 02/17/13 01:52 PM

Maurice's dark skies result from the use of a software 'filter' to cut out sky glow. I believe he doesn't use a physical filter, either!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Dwight J
scholastic sledgehammer
*****

Reged: 05/14/09

Loc: Lethbridge, Alberta, Canada
Re: Which camera? new [Re: GlennLeDrew]
      #5685490 - 02/17/13 04:33 PM

Must be quite the filter. This would be a revolution in astroimaging. Must be similar to the filter that adds color to the final raw image output of the Lodestar C camera. "This means that your ‘raw’ images are initially
black and white, with a ‘tiled’ look, owing to the filter grid. Conversion into colour is usually handled
by processing the raw images on the following day, when you can take time to optimise the colour
balance, saturation etc." is a quote from the manual for the camera so any images that are in color have been post-processed. Various "challenges" by Nytcam to the output of a Mallincam would be bogus as the Mallincam does not require any post processing to get a color image. The real challenge would be to see the various cameras in action on NSN but I won't hold my breath.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | (show all)


Extra information
3 registered and 9 anonymous users are browsing this forum.

Moderator:  David Pavlich, JayinUT, Mr Greybush 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3403

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics