45 replies to this topic

[Jan_Fremerey]

opinion

Results
 

[Al Paslow]

 

Amp glow is of absolutely no relevance when you're only capturing an ROI of three to four hundred pixels from the middle of the sensor, particularly at frame rates of 100+ fps.

 

Of course, but both 224 and 662 cameras are sensitive enough for some DSO imaging the 662 is a more versatitle camera due to lack of amp glow regardless, should you wish to attempt such imaging.

 

It's an added bonus.

[TareqPhoto]

I bought that 662 for two reasons:

 

1. It has better price, nice discount by end of last year.

 

2. It is an upgrade of 462 color that ZWO discontinued, so i didn't have a choice but 662 itself.

 

Another reasons can vary such as the pixel size of it, but the main thing was QE maybe, at the end i have to choose something, i wanted a camera in color that can be an equivalent to my ASI290mm, i was planning to buy 290MC in the past but i couldn't, and the time was passing that 462 was available then discontinued, i hope i didn't make a mistake by choosing 662.

[Tulloch]

Results
 

Unverified, and not accepted by anyone else in the planetary imaging community. 

[RyzenAMD]

I bought my ASI662MC camera for double stacking F/6.3 reducer/correctors for DSO imaging in my C8 and C11 telescopes. I might even do some planetary imaging as well, but bought for the former not the latter.

[Jan_Fremerey]

Unverified, and not accepted by anyone else in the planetary imaging community. 

  ? ? ?

[Tulloch]

  ? ? ?

Your therory is unproven, unverified and at odds with the accepted advice from many others in the field over many years. Provide better, side-by-side proof of a barlowed vs unbarlowed measurement under the same atmospheric conditions and get it accepted by the semi-pros in the field.

 

Until there is a widespread acceptance of your theory, you need to stop confusing others as it's unhelpful to everyone.

[Jan_Fremerey]

Until there is a widespread acceptance of your theory, you need to stop confusing others as it's unhelpful to everyone.

I don't disseminate any theory and so need not defend any. I just present and compare results, even better than side-by-side, i.e. out of one and the same set of video data, see above. I'm aware that you don't like my results as they don't comply with rather conventional rules that you disseminate and defend with reference to well accepted large-aperture authors and other people's questionable theories. I think confusion may be dissolved on the basis of clear results and open discussion.

[Tulloch]

I don't disseminate any theory and so need not defend any.

Every time you advise someone to capture at half the recommended focal ratio you are disseminating your theory and dismissing the other. This leads to confusion to the newcomer who doesn't have any experience.

 

 I just present and compare results, even better than side-by-side, i.e. out of one and the same set of video data, see above.

Since you are promoting the theory that a barlow is not required when capturing, side-by-side measurements with and without a barlow are an absolute requirement. Until you do this measurement (and trust me, I will be doing it as soon as the planets come back again), your theory is untested and unvalidated. Who knows what's happening to the data taken at a higher focal ratio when you downsample it? The tests need to be done before any theory is accepted, this is how science works.

[Paradoxdb3]

Every time you advise someone to capture at half the recommended focal ratio you are disseminating your theory and dismissing the other. This leads to confusion to the newcomer who doesn't have any experience.

Since you are promoting the theory that a barlow is not required when capturing, side-by-side measurements with and without a barlow are an absolute requirement. Until you do this measurement (and trust me, I will be doing it as soon as the planets come back again), your theory is untested and unvalidated. Who knows what's happening to the data taken at a higher focal ratio when you downsample it? The tests need to be done before any theory is accepted, this is how science works.

Can you two hold off a bit... I need to make some popcorn, and I'm fresh out of soda. 😁

[TareqPhoto]

Also it is about 224 vs 662, i have 662 and i don't have 224, simple as that.

[Jan_Fremerey]

(1) you are disseminating your theory

(2) Who knows what's happening to the data taken at a higher focal ratio when you downsample it?

(1) Would you kindly accept that there is no theory. I just observe and compare: if I get the same result from less pixels then I probably had some superfluous pixels before.

(2) Downsampling an image by 1/2 definitely erases 75% of pixel content. This also happens when taking a 2x Barlow out from the optical train during image capture.

[Tulloch]

This conversation can serve no purpose anymore.

 

Just be aware that every time you promote your theory to a newcomer about the recommended focal ratio to image at, I will comment that the recommended focal ratio is 5x the pixel size of the camera. Until you produce images taken with and without a barlow under good to excellent seeing conditions showing no difference.

[TareqPhoto]

Let's put it in another way

 

Recommend or mention the best planetary camera that can be used with following scopes focal ratios, just mention without giving long speech, if it is about 5 * pixel size rule then mention the model please.

 

A. F = 10

 

B. F = 12

 

C. F = 15

 

D. F = 20

 

E. F = 24 or 25

 

F. F = 30

 

G. F = 35

 

H. F = 40

 

I will appreciate if you can put camera model next to each one above, this way i will know what it should be if i want to use any scope within those above.

 

Thank you

[RedLionNJ]

Since it appears I beat both Andrew and Jan to it, my answers below ... 

 

Note that 'best' may be somewhat subjective. These matches are simply based on pixel sizes. There may be larger format models available in some of the sizes, but a larger sensor is unnecessary when we're in the context of hi-res planetary imaging (we'd typically operate at a smaller ROI anyway).

 

Let's put it in another way

 

Recommend or mention the best planetary camera that can be used with following scopes focal ratios, just mention without giving long speech, if it is about 5 * pixel size rule then mention the model please.

 

A. F = 10        ASI678

 

B. F = 12        ASI183

 

C. F = 15       ASI290  (and several others, such as the ASI462, also with 2.9u pixels)

 

D. F = 20       ASI224

 

E. F = 24 or 25     ASI174

 

F. F = 30         ASI174

 

G. F = 35        We're getting into massive pixel territory here, I'm not sure such a CMOS camera exists (7 microns)

 

H. F = 40        I don't think there is an 8-micron CMOS camera

 

I will appreciate if you can put camera model next to each one above, this way i will know what it should be if i want to use any scope within those above.

 

Thank you

Note if you're imaging at lower elevations, an ADC is also recommended and unless you're about to drop $4,500 on a Gutekunst, you should be limited to F = 20 or higher.

[TareqPhoto]

Since it appears I beat both Andrew and Jan to it, my answers below ... 

 

Note that 'best' may be somewhat subjective. These matches are simply based on pixel sizes. There may be larger format models available in some of the sizes, but a larger sensor is unnecessary when we're in the context of hi-res planetary imaging (we'd typically operate at a smaller ROI anyway).

 

Note if you're imaging at lower elevations, an ADC is also recommended and unless you're about to drop $4,500 on a Gutekunst, you should be limited to F = 20 or higher.

Excellent

 

Let me add to this then.

 

I have two cameras from above [ASI290MM + ASI174MM]  and something else similar [ASI178MC + ASI385MC + ASI662MC], so some pixel sizes i covered already, and for larger focal ratios such as 30 or 35 there is a camera with big pixel size, which is ASI432 and equivalent, this camera has pixel size of 9um, and i bought it mainly for solar imaging, that is why i included F 35 and 40 here, even for planets i might decide to use F/7 scope with Powermate 5x i have, and with extensive i can go even above F/40, so i mentioned just in case.

 

Thank you very much! 

Edited by TareqPhoto, 05 April 2023 - 07:34 AM.

[Jan_Fremerey]

(and trust me, I will be doing it as soon as the planets come back again)

You need not wait for so long. Lunar details may serve as suitable targets as well ...

[Jan_Fremerey]

every time you promote your theory to a newcomer about the recommended focal ratio to image at ...

Newcomers will not be prohibited to have a look at my website ...

[Chorge1972]

Can someone who knows more about that stuff tell me, if I will be fine with:
ASKAR 103 (F7)
ASI622
Barlow 3x
Or will I get better results in the end with just a 2x Barlow?

[Ittaku]

Can someone who knows more about that stuff tell me, if I will be fine with:
ASKAR 103 (F7)
ASI622
Barlow 3x
Or will I get better results in the end with just a 2x Barlow?

The 662 will work much better with a 2x barlow with an F7 scope.

[Jan_Fremerey]

Or will I get better results in the end with just a 2x Barlow?

Following my practical experience in view of getting up shutter speed, frame rates, and field of view, I would rather go without Barlow.

 

CS Jan
 

Edited by Jan_Fremerey, 22 August 2024 - 04:10 AM.