39 replies to this topic

[DFW Guy]

Hi Guys,

I'm thinking about upgrade to the 6200MC and I can't seem to find a good answer to what improvements I'll see with my rig outside of the increased resolution. I'm currently running a 12" f/8 scope without a reducer and one of the problems I'm running into is that on distant targets, I'm running out of pixels to really bring out the image after a crop.

I'm loving the 2600MC for targets that are sub 30 ly but basically when I want to stretch my scope out on distant targets I end up using 10% of the overall image due to the apparent size of farther DSOs.

Would upgrading to the 6200MC help if my intention is to ultimately crop just the center field of the final image?

[Midnight Dan]

If by "increased resolution" you mean more pixels, it will do that.  

 

But in astrophotography, "resolution" usually means the image scale in arc-seconds per pixel - in other words, how much detail you can record.  Since the pixel size in both cameras is exactly the same, you will not get any more resolution (detail) in your images with the 6200 camera on the same scope.

 

The larger señor on the 6200 allows you to see a greater area in the sky - it increases your field of view.  But that assumes your scope is capable of filling that large sensor to the edges without showing aberrations.  Not always a good assumption.  And, if you plan to crop and just use the center, then you get absolutely no advantage with the 6200.

 

-Dan

[DFW Guy]

What I mean specifically, is that if I crop the same region wouldn't the additional pixel count help when cropped due to pixel density? 

 

 

If by "increased resolution" you mean more pixels, it will do that.  

 

But in astrophotography, "resolution" usually means the image scale in arc-seconds per pixel - in other words, how much detail you can record.  Since the pixel size in both cameras is exactly the same, you will not get any more resolution (detail) in your images with the 6200 camera on the same scope.

 

The larger señor on the 6200 allows you to see a greater area in the sky - it increases your field of view.  But that assumes your scope is capable of filling that large sensor to the edges without showing aberrations.  Not always a good assumption.  And, if you plan to crop and just use the center, then you get absolutely no advantage with the 6200.

 

-Dan

[unimatrix0]

 

What I mean specifically, is that if I crop the same region wouldn't the additional pixel count help when cropped due to pixel density?

 What you are looking for is pixel density, yes but these cameras have the same pixel density, but varying size of the sensor. A large sensor will not help you other than widening the field of view of the same target. Cropping in - you are still dealing with the same size pixels as many cameras. For example  if you would take 3 images with 3 different cameras:

 

533mc pro (3008x3008")   vs 2600 mc pro (4000x600)  vs 6200mc pro  (9576×6388) are all 3.76 micron pixel array. 

 

You crop either the 2600 and the 6200 to 3008x3008, you are still at the same resolution as the 533mc pro.   If you specifically bought the sensor for far away tiny objects, then you could have just bought the 533mc pro, it's the same resolution as the 6x more expensive 6200 mc pro, just smaller sensor. 

 

 

You might want to watch this video before you buy things.  

 

 

Huge Telescope. Tiny Sensor. Why?

https://youtu.be/c_G...aHhfYw4SvTVarEv

Edited by unimatrix0, 18 March 2025 - 02:51 PM.

[radon199]

What I mean specifically, is that if I crop the same region wouldn't the additional pixel count help when cropped due to pixel density?

No, the 533 the 2600 and the 6200 all have the same pixel density. A 6200 image cropped to the same region as a 2600 image will be exactly the same resolution and magnification. They would look identical.

The only advantage is you get more pixels around the edges.

[DFW Guy]

The video you linked is mostly about using short exposure times to bypass atmospheric distortions... AKA Lucky Imaging. Has nothing to do with increased camera resolution benefits or the limitations of increasing pixel count on my scope. 

 

Original post edited for more clarification that provided the solution 

 

 

 What you are looking for is pixel density. A large sensor will not help you other than widening the field of view of the same target. Cropping in - you are still dealing with the same size pixels as many cameras. For example  if you would take 3 images :

 

533mc pro (3008x3008")   vs 2600 mc pro (4000x600)  vs 6200mc pro  (9576×6388) are all 3.76 micron pixel array. 

 

You crop either the 2600 and the 6200 to 3008x3008, you are still at the same resolution as the 533mc pro.   If you specifically bought the sensor for far away tiny objects, then you could have just bought the 533mc pro, it's the same resolution as the 6x more expensive 6200 mc pro, just smaller sensor. 

 

 

You might want to watch this video before you buy things.  

 

 

Huge Telescope. Tiny Sensor. Why?

https://youtu.be/c_G...aHhfYw4SvTVarEv

Edited by DFW Guy, 18 March 2025 - 02:58 PM.

[DFW Guy]

Gotcha, I just ran it through Telescope simulator and yeah it's the same. So the only real benefit from going to the 2600MC to the 6200MC is the increased field of view? Are there any solutions out there that just increase pixel density to allow for tighter cropping of far away DSOs or is the only solution is to just increase the size of the scope?

 

 

No, the 533 the 2600 and the 6200 all have the same pixel density. A 6200 image cropped to the same region as a 2600 image will be exactly the same resolution and magnification. They would look identical.

The only advantage is you get more pixels around the edges.

[daveco2]

Those two sensors have the same resolution.  What's different is the field of view.  That means you could do more cropping of the large sensor, but that won't change the resolution of the image.

The key is image circle of the scope compared to sensor size.  If the image circle fits an aps-c size sensor, then there would be no reason to go to a larger full-frame sensor.

[DFW Guy]

Yeah, I was misunderstanding how the increased resolution was achieved. I assumed it was via increased pixel density rather than just increasing the size of the sensor itself. So it seems the only way to really increase the "resolution" and by that I mean the additional pixel density that would help with targets that are very far away is to find a camera that has more pixels with the same surface area as what I'm using now OR increase the size of my telescope.

 

 

Those two sensors have the same resolution.  What's different is the field of view.  That means you could do more cropping of the large sensor, but that won't change the resolution of the image.

The key is image circle of the scope compared to sensor size.  If the image circle fits an aps-c size sensor, then there would be no reason to go to a larger full-frame sensor.

[Jim Waters]

If you are considering the ASI6200 you need to 'make sure' the scope can deliver an image circle for that sensor.  Otherwise you are wasting your money and time.

[Spaceman 56]

Would upgrading to the 6200MC help if my intention is to ultimately crop just the center field of the final image?

No.  if you want more details in the cropped image, I believe you would need a camera with a smaller pixel size.

 

otherwise the cropped image would have the same resolution.

 

experts will know more. 

[MartinNI]

The sensor IMX715 and IMX183 have both smaller pixels, and cameras are affordable. Good for tiny objects. But have you consider a scope with more focal length ?

[unimatrix0]

Nobody mentioned it, but the CCD suitability calculator will tell  you the size of the pixels match the best with your telescope. 

 

Ultimately though, don't expect to change much about the image itself - as far as how much details revealed based on pixel size- , because you (and everyone else) is more seeing limited and diffraction limited. 

https://astronomy.to...ccd_suitability

 

 

What you would need to get more details of faint and small DSO"s is ultra dark skies and observatory level telescopes. 

Edited by unimatrix0, 18 March 2025 - 05:19 PM.

[Jared]

You are already at about 0.33 arc seconds per pixel. Even a camera with smaller pixels, thus higher pixel density, is unlikely to yield more resolution. You would need either exceptional seeing or very short exposures in order to see any improved resolution. Once you get to a 12” scope with pixels under 4 microns you are about at the limit of what typical seeing can support. Maybe if you find a place for your scope with exceptional seeing? Or if you are willing to try lucky imaging? That has limited benefits on galaxies, though, due to low surface brightness.

Honestly, the next step to better resolution is likely to do some work on data quality. Is your AF process fully optimized? Are you re-focusing frequently enough? How good is your guiding? Separate guide scope or OAG? How are you managing tube currents? Are you making sure luminance frames are captured through the lowest possible air mass? Collimation as close to perfect as you can arrange?

[Midnight Dan]

Gotcha, I just ran it through Telescope simulator and yeah it's the same. So the only real benefit from going to the 2600MC to the 6200MC is the increased field of view? Are there any solutions out there that just increase pixel density to allow for tighter cropping of far away DSOs or is the only solution is to just increase the size of the scope?

Correct - the only advantage is increased field of view.

 

The pixel density is a function of the sensor in the camera.  So one solution would be to buy a camera with smaller pixels.  However, like everything, there's a tradeoff.  Smaller pixels will collect fewer photons per unit time and therefore, given the same integration time, the signal to noise ratio will be worse with smaller pixels.

 

Increasing the size of the scope is the best solution.  A longer focal length will give you more resolution in the image, within the limits that your local seeing imposes.  And a larger aperture scope will collect more photons so it will give you better signal to noise ratio than a camera with smaller pixels.

 

-Dan

[Fegato]

+1 to Jared's post - that is the critical point in answer to your question

[Andros246]

For y’all wanting to know the 6200mc is just basically two 2600mc stiched together, I know someone who has one and can see the “seam” in his calibration

Edited by Andros246, 19 March 2025 - 11:17 AM.

[premk19]

For y’all wanting to know the 6200mc is just basically two 2600mc stiched together, I know someone who has one and can see the “seam” in his calibration

This is absolutely not the case.

[Jim Waters]

For y’all wanting to know the 6200mc is just basically two 2600mc stiched together, I know someone who has one and can see the “seam” in his calibration

I suggest you check your 'facts' first.

[Andros246]

This is absolutely not the case.

 

 

I suggest you check your 'facts' first.

What would y’all call this then a banding coincidence? 
 

sorry this is not my camera these were the only examples I have. 
 

uncalibrated and a overcorrection flats only image might make it a little more visible you have to stretch really far

 

Edited by Andros246, 19 March 2025 - 01:38 PM.

[Andros246]

You can call me crazy all you want we have no idea EXACTLY how these sensors are made from my quick 15 second google search.

And I know for fact quality ranges a ton some “brand new” 533/2600’s are pretty clean no/very little hot pixels others are all blemished up (once calibrated good as new), we have NO IDEA where zwo gets their sensors from they probably get dibs on Sony’s reject pile. So from my “uneducated lacking facts” comment anything is possible.

Edited by Andros246, 19 March 2025 - 02:13 PM.

[hyiger]

I suggest you check your 'facts' first.

The 6200 has an APS-C mode that turns off half of the sensor. I remember reading somewhere that the IMX455 is 2 IMX571's bonded together. Guy in my club has one and he can also see a seam running down the center when over-stretching. Regardless of whether true or not (the stitching part) the IMX533, IMX571 and IMX455 are the exact same sensor technology. 

Edited by hyiger, 19 March 2025 - 02:14 PM.

[NorthScope]

I had ASI2600MC, but wanted to test narrowband, so I purchased the ASI6200MM. That works great. I sometimes switch to APS-C (Easy if you use ASIAir).

 

The thing I did not thought about when upgrading from 2600 to 6200 was the file size gets much bigger… So, I needed to purchase a new laptop aswell to be able to process the stacking andd imaging in Pixinsight for a reasonable amount of time 😅

here is the full frame to aps-c switch;

[DFW Guy]

My 12" Meade wouldn't allow for a full sensor view with a 2" OAG-L?

 

 

If you are considering the ASI6200 you need to 'make sure' the scope can deliver an image circle for that sensor.  Otherwise you are wasting your money and time.

[Spaceman 56]

Honestly, the next step to better resolution is likely to do some work on data quality.

 

Is your AF process fully optimized? Are you re-focusing frequently enough? How good is your guiding? Separate guide scope or OAG? How are you managing tube currents? Are you making sure luminance frames are captured through the lowest possible air mass? Collimation as close to perfect as you can arrange?

 

 

Increasing the size of the scope is the best solution.  A longer focal length will give you more resolution in the image, within the limits that your local seeing imposes.  

 

And a larger aperture scope will collect more photons so it will give you better signal to noise ratio than a camera with smaller pixels.

 

-Dan

I agree with both these posts.

 

1. Larger aperture is good.  

 

2. Increased focal length is good.

 

3. Better data quality is Good. Probably the most important part.

 

Put all 3 together and you get the full benefit.