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I would like a chip with more real estate?

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#1 fetoma

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Posted 30 November 2013 - 12:04 PM

Folks,

I'm currently imaging with an SXVF-H9 mono and am thinking about a move to the KAF-8300 chip for the larger FOV. Unfortunately I can't afford the ICX694 based cameras at the moment.

Has anyone made this move that can give me an opinion either way if it's a good or bad move? I'm imaging from a red zone just outside a white zone.

Thanks!

#2 ollypenrice

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Posted 30 November 2013 - 04:06 PM

The chip isn't the camera. Far from it. If you go for the QSI you won't be disappointed. Atik do a good job for much less cost, in Europe at least.
Olly

#3 David Pavlich

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Posted 30 November 2013 - 04:17 PM

Have you thought about the QHY version? Not a bad deal with the filter wheel included.

David

#4 fetoma

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Posted 30 November 2013 - 04:59 PM

Guys,

I'm asking for an opinion on switching chips as I know all about the cameras available.

#5 alpal

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Posted 30 November 2013 - 05:15 PM

Guys,

I'm asking for an opinion on switching chips as I know all about the cameras available.


2 people just gave you an opinion.
What more do you want?

#6 fetoma

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Posted 30 November 2013 - 05:21 PM

How about for you to stay out of it with your smart remarks.

#7 JJK

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Posted 30 November 2013 - 06:27 PM

Guys,

I'm asking for an opinion on switching chips as I know all about the cameras available.


2 people just gave you an opinion.
What more do you want?


The OP was about a possible chip real estate upgrade, not about specific camera manufacturers. Just sayin'.

#8 fetoma

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Posted 30 November 2013 - 07:04 PM

Thanks John. ;)

#9 freestar8n

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Posted 30 November 2013 - 07:23 PM

I went from sxvf-h9 to atik 8300. I'm not sure exactly what you are asking, but yes it is bigger and it is very different imaging with it - mainly due to the shutter, slower downloads, and larger files. It is also bigger and heavier - but not compared to even larger cameras.

In terms of light pollution I have plenty also, so I do mainly narrow band and photometry. The 8300 is not as sensitive there as Sony but it is sensitive and it is bigger than the h9.

I don't get much chance to image but it has been fine so far. The main adjustment is the shutter and slower downloads.

If you have a well corrected field and you aren't currently making use of it, it is very nice to be able to capture it. But if your main interest happens to be small galaxies then that would not be as important.

Frank

#10 fetoma

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Posted 30 November 2013 - 07:45 PM

Thanks Frank. I'm not overly worried about the slower download times, and the shutter shouldn't throw any curve balls either. How will it compare in sensitivity? I currently don't need to take dark frames either. I'm guessing this is the trade off for a larger chip.


#11 PGW Steve

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Posted 30 November 2013 - 08:07 PM

I do narrow band with my 14" LX200R and FSQ, both with 8300 chips. I'm never disappointed with the signal I get, but I don't have anything to compare it to.
Mr. freestar8n mentioned about getting used to the shutter, again, I don't have any other frame of reference, but the shutter to me is transparent as Maxim runs the show and I'm generally not around while things are going on.
If the other cameras don't have shutters, does that not make taking darks a manual intervention type of task?
Again, I have no other experience to compare it to other than I'm happy with the 8300's I have.....Until my 16803 shows up in about 3 weeks. :-D

#12 DeanS

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Posted 30 November 2013 - 09:42 PM

It is worth the move to the larger chip size. If you find the seeing is not good enough to handle the smaller 5.4u pixels you can bin it 2x2 and still have a bigger image than the H9. I started with the H9 and ST2k and now have the 8300 and 4022 chips and like them both.

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#13 JJK

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Posted 30 November 2013 - 10:09 PM

Frank, I too live in a Red Zone (22 miles from the White House), and have been imaging for just under 2 years with OSC CCD cameras (SBIG ST-2000 & STL-11000) and scopes capable of illuminating much larger chips. Here is my take on the matter of chip real estate, ignoring the obvious increase in cost that scales with size.

Larger chips invite more issues with LP gradients. This can be mitigated to some extent with LP filters (I had decent luck with a Hutech LPS-2), and the use of sophisticated software (e.g., Dynamic Background Extraction in PixInsight). Of course, nothing beats a pristine sky, but these things make imaging near "civilization" a more pleasurable experience.

Personally, I really like having a wider FOV that a larger chip affords. After struggling with equipment malfunctions, software maladies, Windoze updating in the middle of an imaging run, frostbite, insect bites, dropping expensive kit in the dark, etc. it's really cool to look at a wider perspective of the data one took on a computer monitor. While staring at the images for hours, the wider FOV allows you to see more DSOs that might otherwise go unnoticed.

The wider perspective also provides the potential for fun juxtapositions. For example, this past August, I imaged Nova Delphini 2013, and the STL-11K allowed me to include the Blue Flash Nebula in the frame. Having an essentially dead star's colorful remnants across the field from an orange-colored new dying star made the image much more interesting.

I recently sold my OSC cameras and am replacing them with monochrome 8300 (just arrived) & 16803 CCD cameras w/fully-loaded color filter wheels (LRGB + 3 nm Ha/OIII/SII). My current strategy is to image NB to beat down Moonlight and nights when there's bad LP (due to more than average water vapor in the sky) and use LRGB filters when the sky is drier and the Moon's asleep. I assumed that the tight bandpass NB filters (especially OIII) will help.

Hope this helps.

#14 Scott Watson

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Posted 30 November 2013 - 10:51 PM

Physically larger chips with larger pixels (at the same read noise figure) are generally a good way to improve light gathering FOV or both.

#15 JJK

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Posted 30 November 2013 - 11:36 PM

I forgot to mention that larger chips require more care with taking and applying flats.

#16 gezak22

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Posted 01 December 2013 - 02:55 AM

...I currently don't need to take dark frames either. I'm guessing this is the trade off for a larger chip.


While I never made the jump from a small sensor to a large one, I do own an 8300 based camera. As long as I have 15+ lights (dithered), I can process them without darks and get images that I am satisfied with in terms of noise. And if I am not, I'll take 10 darks, and reuse those for a year.

#17 freestar8n

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Posted 01 December 2013 - 03:29 AM

Larger chips invite more issues with LP gradients.



Hi-

Yes that is a good point and I agree and I completely forgot about it. I hate gradients and I hate doing any kind of non-deterministic processing. The only way to get rid of gradients is to deduce what the "true" background is and remove it in image processing. Some people don't mind doing that at all, but I really don't like it.

I am at fairly long focal length and mostly do narrow band. I find color work to be fundamentally frustrating in light pollution and I just don't enjoy it.

So yes - that is a good point. The wider field is great when it lets you see more stuff - but will increase color gradients and possibly be a pain processing.

Frank

#18 fetoma

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Posted 01 December 2013 - 08:11 AM

What about filter size? I currently use an SX filter wheel with 1.25" filters. Can I still use them or would I need to move up in size to the 36mm?

#19 freestar8n

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Posted 01 December 2013 - 08:22 AM

Filter size was also a factor for me, but I don't intend to use very fast optics. I have the Atik 9 position filter wheel and want to stay with 1.25" filters. At f/10 I see no problem and in the future I intend to use f/6-f/7 and there may be some vignetting in the corners, but I hope not much.

I believe the 8300 is a good intermediate size that still allows use of 1.25" filters. It depends on how fast the optics are, how close the filters are to the ccd, and how sensitive you are to any vignetting.

I believe others here use f/6-f/7 with 8300 and 1.25" filters but I haven't yet.

Frank

#20 fetoma

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Posted 01 December 2013 - 08:37 AM

My scopes range from f/3 to f/9. Check my sig.

#21 JJK

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Posted 01 December 2013 - 10:29 AM

Larger chips invite more issues with LP gradients.



Hi-

Yes that is a good point and I agree and I completely forgot about it. I hate gradients and I hate doing any kind of non-deterministic processing. The only way to get rid of gradients is to deduce what the "true" background is and remove it in image processing. Some people don't mind doing that at all, but I really don't like it.

I am at fairly long focal length and mostly do narrow band. I find color work to be fundamentally frustrating in light pollution and I just don't enjoy it.

So yes - that is a good point. The wider field is great when it lets you see more stuff - but will increase color gradients and possibly be a pain processing.

Frank


It's certainly challenging, but on the nights with relatively little water vapor here (near DC), the results can be worth the effort. That said, NB filters really increase what we can do from the average backyard.

#22 JJK

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Posted 01 December 2013 - 10:31 AM

I do narrow band with my 14" LX200R and FSQ, both with 8300 chips. I'm never disappointed with the signal I get, but I don't have anything to compare it to.
Mr. freestar8n mentioned about getting used to the shutter, again, I don't have any other frame of reference, but the shutter to me is transparent as Maxim runs the show and I'm generally not around while things are going on.
If the other cameras don't have shutters, does that not make taking darks a manual intervention type of task?
Again, I have no other experience to compare it to other than I'm happy with the 8300's I have.....Until my 16803 shows up in about 3 weeks. :-D


A shutter complicates collecting dawn & dusk flats.

#23 JJK

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Posted 01 December 2013 - 10:36 AM

What about filter size? I currently use an SX filter wheel with 1.25" filters. Can I still use them or would I need to move up in size to the 36mm?


I just received an FLI MicroLine 8300 CCD camera with an FLI CFW2-7 filter wheel. I decided to get 50 mm round filters (36 mm are good enough), which made the rig a bit more expensive, but I am trying to make the system flexible for future camera upgrades.

#24 avarakin

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Posted 01 December 2013 - 08:40 PM

Frank,
I think the main reason for going to 8300 is not FOV but number of pixels. Your current camera is just 1.3Mp, where as 8300 is 8MP. This is equivalent to 32MP DSLR if you pick mono !
Can you use your 1.25 filters? Depends on camera and scope. QSI is expensive but allows to use 1.25 filters. SBIG would work fine with F6 scopes, with faster ones it would produce vignetting which maybe eliminated with flats.

Alex






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