Choosing a planetary camera for a 8" telescope?

[stoffe]

Hello

I am planning to get to the next step from a Toucam to anything better and more sensitive. I have looked at many cameras but I start with my setup.

Scope: 8" f/8 Cave Astrola 1965 realuminized mirror, 1600 mm focal length.

Extender: Televue Powermate 2,5x

Mount: EQ6

And I have taken a few quite good Jupiter pictures but I want to do it better with higher framerate and higher sensitivity. I have looked at both CMOS cameras and CCD cameras and had found following.

DFK 23U618 - USB3.0 camera with a colour Sony 618 CCD sensor 5.6 micron pixelsize

QHY5L-II Colour - USB2.0 camera with a CMOS MT9M034 sensor 3.75 micron pixelsize

ASI 120 - Nearly the same specifications as QHY5L-II Colour camera

Point Grey Flea 3 - USB3.0 with IMX035 sensor and 3.63 micron pixelsize

The cheapest one of these cameras is QHY5L-II Colour and the benefits of that camera is that I can get it very close the rear lens to my powermate which is much harder to do with any of the others.

Any ideas?

[stoffe]

I just did a sampling calculation with some different pixelsizes.

5,6 micron @ 1600 mm + 2,5x = 0,289 pixel/arc second
3,75 micron @ 1600 mm + 2,5x = 0,193 pixel/arc second

The sampling differs 1,5x times between those cameras. So it should be a quite big difference between a camera with 5,6 micron pixel size sensor and a camera with 3,75 micron pixel size sensor. I don't have perfect seeing where I live but it could be good sometimes with a little bit of luck

[GuillermoBarrancos]

I think you are overlooking the QHY5L-II Mono camera.

https://www.teleskop-express.de/shop/product_info.php/info/p5990_ALccd5L-IIm---high-speed-lunar-planetary-camera--max--200-pfs---monochrome-version.html

It's insane in sensitivity for a CMOS sensor planetary camera. Great price too.

Unless you are only interested in a Color camera?

[todd8137]

DMK 21AU618.AS Mono

Every time do not be dazzled by cameras that offer X amount of fps solid build and excellent image quality 30fps is plenty this camera can do 60fps but very rarely used these days people,want to capture 10.000 frames at once the cheaper camera get real warm and that's not all lots of noise as well .

They all do the,same,Jon to some degree but the dmk range are food,unless you want a flea 3 ect

Pat

[stoffe]

Thanks for good answers, I have considered to get a high sensitive mono camera but it seems so difficult do use a mono camera to do planetary photagraphy. I already own a QHY5 mono but I do not own a filterwheel and I don't think my filter that I got i my celestron eyepiece box is suitable for photagraphy.

http://www.celestron.com/astronomy/celestron-eyepiece-and-filter-kit-1-25-in.html

Or how should I think here? Should I get a colour camera to do planetary photagraphy instead?

BTW IC cameras are good on paper but could have some problems with drivers, especially the firewire cameras..

[GuillermoBarrancos]

Thanks for good answers, I have considered to get a high sensitive mono camera but it seems so difficult do use a mono camera to do planetary photagraphy. I already own a QHY5 mono but I do not own a filterwheel and I don't think my filter that I got i my celestron eyepiece box is suitable for photagraphy.

http://www.celestron.com/astronomy/celestron-eyepiece-and-filter-kit-1-25-in.html

Or how should I think here? Should I get a colour camera to do planetary photagraphy instead?

BTW IC cameras are good on paper but could have some problems with drivers, especially the firewire cameras..

I like the extra sensitivity of the Mono cameras and during my 3 years of planetary / white light solar imaging foray I never bothered with RGB filters and just imaged in Mono.

I started with a modded livecam, then to the QHY5v (had bad Luck with a bad unit) and finally switched to a DMK21 mono.

Tho today I wouldn´t buy an IC camera anymore, as they have become more expensive and personally think they are overpriced now.

So personally I would either go for the ASI120M or QHY5L-II mono myself.

But if you want color, the QHY5L-II color is a good camera and will give you "best bang for the buck" at that price.

[Zakalwe]

Thanks for good answers, I have considered to get a high sensitive mono camera but it seems so difficult do use a mono camera to do planetary photagraphy. I already own a QHY5 mono but I do not own a filterwheel and I don't think my filter that I got i my celestron eyepiece box is suitable for photagraphy.

http://www.celestron.com/astronomy/celestron-eyepiece-and-filter-kit-1-25-in.html

Or how should I think here? Should I get a colour camera to do planetary photagraphy instead?

BTW IC cameras are good on paper but could have some problems with drivers, especially the firewire cameras..

Don't shy away from working in mono. I recently started using mono after a long time spent with a DFK OSC.

Yes there is more work to stack 3 separate files, but the processing is a LOT easier as there is more detail in the images.

I always thought that RGB imaging would be a lot harder/more difficult, but in reality it isn't. There's a few more steps, but the processing is easier due to the higher quality of the information.

Plus, using a program like Firecapture makes the job much easier as you can set it up to automate the filterswaps and focusing between avi captures.

Here's a little PDF that I pulled together to demonstrate the difference.

Mono Jupe.pdf

I really, really wish that I had started with mono much earlier.

[stoffe]

Okay you guys have conviced me that mono is so much better, that PDF file have VERY nice pictures of Jupiter!!

This is my best Jupiter picture that I have ever made and that is taken with a SPC900NC Toucam.

Should I use my QHY5 mono camera or should I buy a QHY5L-II camera instead?

This is a very cheap filterwheel, but its three way and it should be enough to do planetary I guess? Or do I need a 4 way with a luminance filter too?

http://www.ebay.com/itm/1-25-color-filter-wheel-colour-filter-wheel-filters-/161184224928?pt=UK_Telescope_Eyepieces&hash=item25875416a0

BTW I live on 60 degree latitude, but I guess its worth having a mono camera anyway even if the planets never reaches zenit..

[Pete Presland]

after doing some research, i would say the DMK 21AU618.AS  is probably better than the ASI120mm, maybe   but it is considerably more expensive as well. i thought about the two and went for the ASI purely on price and the strength some pretty spectacular images being produced already by the ASI. obviously the amount you wish to spend is down to you, but have a google of some of the images produced with the individual cameras first. i would never go back to a OSC, mono is much better and worth the extra effort.

whichever you choose you will always be relying on decent seeing conditions.

[stoffe]

I think the smaller pixels are better for my purpose? I wrote this in this thread already but this is a calculation that I have made based on telescope setup.

5,6 micron @ 1600 mm + 2,5x = 0,289 pixel/arc second
3,75 micron @ 1600 mm + 2,5x = 0,193 pixel/arc second

It is the pixel size that is the biggest difference between 618 based cameras and ASI/QHY5L-II cameras. What are the better advantage with a 618 based camera?

[GuillermoBarrancos]

I honestly think the Imaging Source cameras are no longer Worth the price they are asking currently.

CMOS sensors have come a huge way and the QHY5L-II mono camera is really showing this. It´s just the best bang for the buck you can buy at this moment.

But that´s just me.

[stoffe]

1. Yes I agree, but how should I combine that QHY5L-II mono camera with suitable filters? Any recommendations of filter wheels?

2. Should I mount the filters nearest the camera or is it okay to mount the filter before the powermate?

[SkyGibbon]

I would also choose the DMK21mono. If you plan on lunar or solar also, I would get the DMK41 mono. Actually, I would get Celestrons Skyris versions of these. I have the 445 Skyris, which is the same as the DMK41. Only, it has 12 bit color compared to only 8 bit on the IS camera .

Any manual 5 position filter wheel would be fine.

[SkyGibbon]

Here is the first shot with my new 8" Edge SCT with the DMK21 mono.

[todd8137]

Very nice image I prefer IR images 685/742nm 300 stacked from 1000 dmk 21 mono

[riklaunim]

ICX618 based cameras, like DMK21AU618 were the best planetary cameras for quite a long time. Now many top planetary images use ASI120MM or QHY5L-II cameras equipped with the same Micron CMOS sensor. It was a surprise but this sensor actually has very good performance. It has bit more sensitivity in visible light, and bit less in infrared, plus it's bit bigger with more pixels so it's also more efficient on Moon. A part of the success is much lower price.

From Sony CCD there is also ICX693 in Point Grey Blackfly camera - also very cheap like the ASI/QHY. It's Gigabit Ethernet and 50 FPS at full frame (slightly bigger than ICX618). IMX sensors aren't that good, and before buying any camera with such CMOS check gain values it has (like Point Grey likes to give very very low gain values for most of it CMOS based cameras making them nearly useless in astrophotography).

As for f-ratio and pixel size - you always pick the best f/ratio for given pixel size. The smaller pixel the faster the optimal f/ratio is. For those small pixels you don't use f/25 but rather f/15..20 depending on seeing. (or like f/10 on dimmer planets like Saturn low on the sky).

[GuillermoBarrancos]

I would also choose the DMK21mono. If you plan on lunar or solar also, I would get the DMK41 mono. Actually, I would get Celestrons Skyris versions of these. I have the 445 Skyris, which is the same as the DMK41. Only, it has 12 bit color compared to only 8 bit on the IS camera .

Any manual 5 position filter wheel would be fine.

The DMK21AU618 costs 369 pounds.

The DMK41 costs 479 pounds.

Lets not even start on Celestron Skyris cameras, which are even more overpriced.

Why would I spend that kind of Money, when I can buy the QHY5L-II Mono for 229 pounds or the ZWO ASI120M for slightly more.

If I really desperately wanted a CCD planetary camera, I rather dump 399 pounds for the QHY IMGOH, which has a much better build that includes cooling.

Don´t get me wrong. Imaging Source cameras have been the "bomb" in planetary imaging for years. I had the DMK21 Mono myself. But not anymore. Especially since the price increase. I would not buy an IC camera anymore today.

[Zakalwe]

If I really desperately wanted a CCD planetary camera, I rather dump 399 pounds for the QHY IMGOH, which has a much better build that includes cooling.

The cooling isn't used in planetary imaging, is it? So unless you start to use it for DSO (and the chip is tiny) then it's a feature that you'd pay for and not use.

[GuillermoBarrancos]

The cooling isn't used in planetary imaging, is it? So unless you start to use it for DSO (and the chip is tiny) then it's a feature that you'd pay for and not use.

I assume there are advantages of having cooling for planetary imaging on hot summer days. Especially in the middle of the day with Solar imaging.

I guess it depends how much time you spend imaging on a given day, if it´s necessary or not.

But yes, it´s also a nice extra feature if you want to try out some longer exposures on small DSO targets.

But either way, I would not pay that kind of Money on a planetary camera anyway, when I can get excellent results for half the price.

[SkyGibbon]

Buy what you want. I gave an opinion.

By the way, I can get Skyris cameras cheaper than IS cameras. So your not correct.

[Cornelius Varley]

Buy what you want. I gave an opinion.

By the way, I can get Skyris cameras cheaper than IS cameras. So your not correct.

The UK prices quotes are correct. What they are in the US is an entirely different matter.

[SkyGibbon]

Yea, I should have payed attention where the op was from.

Anyways.........buy whatever you like. Your money.

[stoffe]

Hello, thanks for many replys here! Very kind of you all! I have read every answer in this thread and I have some new questions. I have numbered them so they are more easy to respond.

1. How do I know if I need a cooled planetary camera? Is it the noise pattern that increases? That should not be a big problem if I stack the movie (which I am going to do).

BTW it is always below 0 degree Celsius (I think it is 32 degree F if anyone is using that scale) and I do not have dark skies in the summer. I live in Sweden on the 60:th degree latitude Solar photography is interesting but I do not own a solar scope.

ICX618 based cameras, like DMK21AU618 were the best planetary cameras for quite a long time. Now many top planetary images use ASI120MM or QHY5L-II cameras equipped with the same Micron CMOS sensor. It was a surprise but this sensor actually has very good performance. It has bit more sensitivity in visible light, and bit less in infrared, plus it's bit bigger with more pixels so it's also more efficient on Moon. A part of the success is much lower price.

From Sony CCD there is also ICX693 in Point Grey Blackfly camera - also very cheap like the ASI/QHY. It's Gigabit Ethernet and 50 FPS at full frame (slightly bigger than ICX618). IMX sensors aren't that good, and before buying any camera with such CMOS check gain values it has (like Point Grey likes to give very very low gain values for most of it CMOS based cameras making them nearly useless in astrophotography).

As for f-ratio and pixel size - you always pick the best f/ratio for given pixel size. The smaller pixel the faster the optimal f/ratio is. For those small pixels you don't use f/25 but rather f/15..20 depending on seeing. (or like f/10 on dimmer planets like Saturn low on the sky).

2. I got f/20 with my 8" f/8 long focus Cave Astrola Newtonian with a 2,5x power mate so it seems like a pixel size with 3,75 micron pixel would suit me perfectly. It would be a pixel scale of 0,193 pixel/arc second. The Sony CCD - ICX693 would give me 0,30 pixel/arc second. That are even lower pixel scale then a Toucam are if it would be possible to mount a Toucam so near the back lens of the power mate. I know there are some nice adapters but I don't know it it worth it. Do I think right here?

I think a QHY5L-II is the best bang for the buck.

3. Anyone that can recommend me any filters for a mono planetary camera? Is it only RGB filters or should I get any other filters?

Very nice pictures of Jupiter you guys have posted here! I wish I can take good pictures too like yours, that is my purpose.

[oldpink]

I'm no expert but I am very happy with my ASI 120MC

my Canon is also extremely good for planetary work but at twice the price of the ASI

the ASI is so far the better camera for planetary work in regards to detail and colour depth
and I constantly see other members post great shots with the ASI and it works with all the major software packages
initially it was a toss up between a QYH and the ASI, for me the ASI just had the edge from the research I did

thoughts of a novice

[riklaunim]

You cal always change Barlow to get optimal f/ratio. 2.5x gets weaker with distance so it will be bit less than f/20 so quite good for 3.75 pixels. If you would pick bigger pixels in ICX693 then you just need different Barlow and thats all.

As for filters infrared passing filters are handy for some luminance imaging of planets and Moon (Baader IR-Pass, ProPlanet 742 or for example red/orange visual filters. Red/orange will be brightest but with lesser "improving" effect).