Camera time

[rumples riot]

Hi all,

I need some advice from the more experience planetary imagers. The next step has come for my planetary imaging. I want to advance from the Toucam to something else. Trouble is I don't know what I am looking at in terms of sensitivity, image scale, pixels etc etc.

I would also like some recommendations on which camera. Model numbers and makes would be very helpful.

I do have a budget. I don't really want to spend anymore than $1000.00 but would consider more expensive camera's if I am going to get better results.

Also I need some info on automated colour filter wheels and colour filters. Recommendations please and can you give your reasons why?

Paul

[gbeal]

Heck, the bug has bitten. Bird is the one to ask by all accounts.

[bird]

Paul, I'm sure you've heard this all before, but anyway...

I'd say go for a monochrome camera + filter wheel, computer controlled if at all possible. There are a few on the market, I can only say that the Tru-Technologies "supa-slim" wheel + Astronomik RGB filters have worked very well for me.

www.trutek-uk.com
www.astronomik.de

On the choice of high-speed monochrome camera, I'd suggest looking at two companies:

www.theimagingsource.com (DMK21AF04 or DMK21AF03 cameras)
www.ptgrey.com (Dragonfly, Dragonfly2 (and the hi-res versions of each) and Dragonfly Express

These are all good cameras, and firewire gives you maximum compatibility. Which one should
you pick? Well, that's up to you I guess... the DX is the most future-proof because of it's
enormous capabilities, ie it can transfer at 800Mbit which comes to about 240 fps in 8 bit mode
or 120fps in 16 bit mode and so that gives you a fair bit of future proofing.

But I also know plenty of people using the DMK cameras and getting excellent results. The only place you might find a limitation with these cameras is when you want to go past about 30fps, and they are also 8 bit data only (from memory, I might be wrong here).

Do you have an electronic focusser? I'd also rate that as very important for planetary stuff.

regards, Bird

[rumples riot]

Thank you Anthony for the info. This will get me on the right track.

Yes, I have an electric focuser. Well, it is in Australia in some terminal awaiting the next stage of delivery. I have a Moonlite electric focuser on its way to me. I had hoped I would have it over the weekend but that is our postage system.

In terms of the cameras, do you record at 16bit or 8bit? I assume you image in 16 bit.

What sort of image performance gain did you notice using your current OTA going from the Toucam to the dragonfly? Was it significant? I have seen your images and commented many times, but would like your own perceptions.

What software if any do I need, can I use K3CCDtools for image capture?

Thanks once again.

[Striker]

Why dont they make these planetary camera's with more rezolution....640 x 480 which is 1/2 a megapixel total rez is very poor quality when it comes to rezolution...it's ok for small pictures but terrible if you wanted to blow it up at all.

I'm not knocking these Dragonfly camera's....I'm sure their great if Bird recomends them..I'm saying this in just a general terms with all Planetary cams.

With todays technology why cant they make a High frame rate camera with say 1-2 megapixel...at least then you could blow it up to a nice size.

[bird]

Tony, you can get higher resolution cameras if you want - there are 1024x768 and 1280x1024 versions of these cameras, but if you're just after planetary imaging then all those extra pixels around the edge will go to waste.

Also, more megapixels means more data to transfer, and so the maximum fps is lower. That's one tradeoff that you don't want to make. You can always make the planet larger by using a longer focal length, in practice I haven't seen anyone using a fl long enough that a planet doesn't fit in 640x480, usually it gets too dim before that happens.

Paul, yes I image in 16 bit these days, but like everyone else I have to wait for good conditions before the difference will be evident. I'm hoping to get another go at saturn sometime soon when then weather clears up, and then some serious jovian imaging come feb/march next year.

I think the improvement is clear enough already, looking at the mars images from snake valley and the one imaging run on Saturn last week - both gave results much better than my old fire-i could do, and in turn it was an improvement over my ToUcam...

regards, Bird

[davidpretorius]

yes, what bird said!

[rumples riot]

Anthony, I can think when the 640x480 will not accomodate a planet. When I have a 5x in with the lx200 10" Jupiter was so big that it would not fit inside the screen. The image was 5inches wide. Largest I have ever seen Jupiter.

In regard to the camera, that is not quite what I meant. I meant when you see the image on the screen does it look better to you when doing your AVI's. Yes your images are good but I cannot say that the images are better than your images early this year. They look smoother to me. What I was looking for your impressions.

[bird]

Not quite sure what you're looking for here Paul - to me the end result is what I am after, if that means pushing the camera to the limit so that the live data looks very dim and noisy then that is what I will do.

It's also a bit early to comment on how the new cameras are working out, I have 1 mars image and 1 saturn image so far - that's only 2 images to compare to the 20 or 30 images taken earlier this year with the 7-bit fire-i camera.

For the mars image from Snake Valley I was using exposure times around 18ms for the red channel, that would have been impossible to do with the fire-i because it did not allow me to set exposures to anything less than 33ms, but even at 33ms the fire-i was extremely noisy. All the Jupiter images earlier this year were done with the fire-i working at exposures of 40ms (25fps). I'm hoping next year with the new gear to make a large improvement on that but I don't know how it will work out until I try - we should have this conversation again in about April.

But my impresions are very simple - the new breed of fast 16bpp monochrome cameras leave the old cameras for dead :-)

regards, Bird

[bird]

Oops, forgot to reply to this bit...

What exposure time were you using for this? If it was a ToUcam at 5fps then that would be around 200ms which explains why you were able to see an image. You'll probably find that much shorter exposures will give you more detail, mostly because of less time for atmospheric blurring, say exposures around 100ms or less, ideally less than 40ms. This also means that the image gets a lot dimmer and you might find that you have to reduce the magnification so Jupiter is no longer a problem on a 640x480 ccd.

Sorry, I hope that's not too convoluted an explanation for this time of morning...


regards, Bird

[rumples riot]

With the Dragonfly 2 and dragonfly can this be directly connnected to a laptop. I have relatively new dell inspiron (last year). The brochures mention a card interface. How do you hook up your camera? Did you have to install the card?

[bird]

Paul, I have an inspiron 8500 and the camera works fine. PGR supply a PCI firewire card for you to put into a normal PC case, not a laptop, just in case you don't have a firewire port.

If your insprion has a firewire port then you're ok. Mine is on the left lahd side just past the card slot, but maybe it's moved on newer models. It'll be a small rectangular 4-pin port.

Laptop firewire ports don't supply power, so you will need a powered firewire hub between the laptop and the camera to supply 12v to the camera. This is actually an advantage anyway, cause you can run an "ultra thin" 1m firewire cable from the hub to the camera and a normal (heavier) cable from the hub back to the laptop.

Check out your local Apple dealer, they sell very thin firewire cables for use in mobile devices, that's where I got mine. It weighs almost nothing.

regards, Bird

[rumples riot]

Anthony, just checked and I have a fire wire outlet in the same position. So that is good news. Just need the hub and might get the dragon fly or the dragonfly2 both have high download rates but also have colour, which I might dabble with before I go the colour wheel. What are ytour thoughts on this?

[bird]

It's up to you Paul, but if it were me I would go for monochrome camera + filter wheel.

Once you buy a colour camera you're stuck with it - you can't convert it back to monochrome unless you're really serious and de-solder the ccd and replace it. At least with a monochrome camera you can add a wheel and colour filters to do colour...

I guess it can seem a bit daunting to go from colour to monochrome + filters, but I don't know anyone who has gone that way and then come back to one-shot colour :-) You could also ask Chris Go in the Philippines, he has just made the same change.

Bird

[bird]

The dragonfly2 is a brand new camera that uses some of the same electronics as my DX. It looks like a very nice unit. I've been considering what I would buy next (haha, when I win lotto) and the high-res version of the Dragonfly2 looks very appealing. 4.65u pixels give a larger image scale, compared to the normal dragonfly and my DX at 7.4u.

It's always a tough choice - the larger (7.4u) pixels have a greater dynamic range and lower noise, but the tradeoff is that the image is smaller. I have sort-of made up for the smaller image scale by using a 5x powermate and extension tubes to get it to 8x.

Bird

[rumples riot]

Yeah might ask Chris; its just that I am concerned with trying to focus each time with the colour filter and run an avi for jupiter all in 60-90 seconds. I am not that clever when it comes to writing a sub rountine or program to have the focus set properly for each run. At least with colour I can do the run and not worry too much. You have a program that refocuses for each colour don't you? This would mean you have a focuser which is attached to the computer. Am I right in thinking this?

[bird]

I have a JMI focusser that uses a serial port to connect to the computer, so I wrote a simple program to control it (it came with software, but of course it was for Windows whereas I use Linux).

It does make a difference to focus each colour, but look at it this way - with the colour camera you're only taking a single focus, so what do you have to lose? If you use the monochrome camera and take a single focus then you're no worse off, and when you have time to work on it you can upgrade the monochrome setup to let you take 3 focus points, something that can't be done with the colour camera.

regards, Bird

[anthony2302749]

Hi all

Well this is a long the same line as the topic. As I own a Lumenera LU075 colour camera for about six months. I have found it to be a great camera and am starting to produce some very nice images with it. I am now considering my next camera and agree with everything Anthony has mentioned. My next purchase will be a monochrome camera plus filter. There is a definite advantage with imaging in full RGB plus high download.

Anthony Mc