ASI 1600 and Microlensing

[spillage]

No its on the sensor. Light bouncing off the sensor lenses causing the light to go into neighbouring ones from what I can remember.

[JamesF]

14 minutes ago, spillage said:

Your just up the road from me. So if at any point your really thinking about it give me a shout and you can you always give my 1600 a run one night on your kit. I find that the ed80 suffers more than the quattro or 130pds.

That's a very kind offer Mark, thank you.  Perhaps the 190MN would work out even if the 80ED didn't.  Do you use the reducer/flattener with your 80?

James

[spillage]

@JamesF Yes I use the skywatcher reducer. I have only seen it a couple times on really bright stars but maybe its always there and I just have not noticed.

[Adam J]

11 hours ago, newbie alert said:

Not sure that's the way, I've seen plenty of images with small aperture and focal length scopes with micro lensing effect..

Where they f6 or slower? You see it on everything it's just worse in those instances. 

[Kaliska]

Just to add this in here, I get the micro lensing effect at F5.8 on my TS100Q

 

[Rodd]

11 minutes ago, Kaliska said:

Just to add this in here, I get the micro lensing effect at F5.8 on my TS100Q

 

Well--that look like a halo--which is different than the microlensing effect.  Can't see the whole star though.  I'll take halos anyday over microlensing!

Rodd

[Laurin Dave]

1 minute ago, Rodd said:

Well--that look like a halo--which is different than the microlensing effect.  Can't see the whole star though.  I'll take halos anyday over microlensing!

Rodd

Looks like both to me although the microlensing is faint..  there are some arcs just inside the main halo and faint circles outside

[Rodd]

4 minutes ago, Laurin Dave said:

Looks like both to me although the microlensing is faint..  there are some arcs just inside the main halo and faint circles outside

I am not sure--there are variations in the background outside of the halo that look like they may correspond to what you see as dark spots in the halo.  Anyway--it looks way different than my microlensing artifiacts I have gotten.  The one I got for the above HH is the strangest one I have gotten--different than the ones I got with M13--probably due to the star being brighter.  I will post it later.

Rodd

[newbie alert]

17 hours ago, Adam J said:

Where they f6 or slower? You see it on everything it's just worse in those instances. 

I don't see f ratio as fast or slow, I see it as wider fov

But since you ask , yes a f5 frac was the last one I see

[newbie alert]

2 hours ago, Kaliska said:

Just to add this in here, I get the micro lensing effect at F5.8 on my TS100Q

 

I see that as a halo, not microlensing..

Are you using more than 1 filter ie a light pollution filter, is your filter as close to the sensor as it can be?

[Rodd]

23 minutes ago, newbie alert said:

I don't see f ratio as fast or slow, I see it as wider fov

But since you ask , yes a f5 frac was the last one I see

But it is not just a FOV thing. For example, you can use an F8 focal length then add a barlow to make it  F15 focal length and increase your sensor size to maintain the FOV (up to a point).  I know if I get a full frame sensor my F10 C11Edge will have a wider FOV than my F7 C11Efdge with the ASI 1600.  The image circle may be smaller, but still bigger than most sensors people use. 

[newbie alert]

23 minutes ago, Rodd said:

But it is not just a FOV thing. For example, you can use an F8 focal length then add a barlow to make it  F15 focal length and increase your sensor size to maintain the FOV (up to a point).  I know if I get a full frame sensor my F10 C11Edge will have a wider FOV than my F7 C11Efdge with the ASI 1600.  The image circle may be smaller, but still bigger than most sensors people use. 

Still quoting in f ratio, f8 is the focal ratio..you said f8 focal length??  And the add a Barlow to make it f15 focal length???

Full frame sensor will have a wider fov than a 1600

Your c11 edge will have a reducer to make it f7?

I personally feel if you scope has a bigger imaging circle the bigger the pixels you can use..

Edited October 17, 2019 by newbie alert
Added info

[Rodd]

Just now, newbie alert said:

Still quoting in f ratio, f8 is the focal ratio..you said f8 focal length?? 

Full frame sensor will have a wider fov than a 1600

Your c11 edge will have a reducer to make it f7?

I personally feel if you scope has a bigger imaging circle the bigger the pixels you can use..

Sorry--I meany focal ratio.  You are mixing points--I agree with that, but  my point is, an F5 scope will only have as wide a FOV as the sensor can accomodate.  So an f8 scope can produce a wider FOV image than an f5 scope if the F/8 scope has a larger sensor.  And, one can design a scope to have widely variable FOVs.  Not all f/5 scopes have the same FOV.  My point is focal ratio is not just a FOV thing as you suggested.  It is a speed thing as well.  But the important thing to remember is speed is more related to aperture than focal ratio.  I shoot at F3 with my FSQ at 4", and I see no appreciable speed over F5.  BUT-give it an extra couple inches of aperture--like teh Epsilon, and speed goes way up.

[Rodd]

Why am I even messing around with the ASI 1600--here is an image of the horsehead using the same scope (TOA 130 with reducer) and STT-8300.  8 hours of data....no comparison!  I should just go back to using this camera.  I had jamming issues with filter wheel--but SBIG and OPT could find no issues with it--so maybe its me?  I guess I should try the ASI 1600 with reducer first--but chances are....then again, teh STT-8300 and self guiding filter wheel will not work on teh FSQ with .6x reducer--takes up too much backfocus.   Back to the FSQ!

Edited October 17, 2019 by Rodd

[Allinthehead]

1 hour ago, Rodd said:

Why am I even messing around with the ASI 1600--here is an image of the horsehead using the same scope (TOA 130 with reducer) and STT-8300.  8 hours of data....no comparison!  I should just go back to using this camera.  I had jamming issues with filter wheel--but SBIG and OPT could find no issues with it--so maybe its me?  I guess I should try the ASI 1600 with reducer first--but chances are....then again, teh STT-8300 and self guiding filter wheel will not work on teh FSQ with .6x reducer--takes up too much backfocus.   Back to the FSQ!

I always thought your images were far superior with the Kaf sensor and looking at that one it's obvious. 

[newbie alert]

3 hours ago, Rodd said:

Sorry--I meany focal ratio.  You are mixing points--I agree with that, but  my point is, an F5 scope will only have as wide a FOV as the sensor can accomodate.  So an f8 scope can produce a wider FOV image than an f5 scope if the F/8 scope has a larger sensor.  And, one can design a scope to have widely variable FOVs.  Not all f/5 scopes have the same FOV.  My point is focal ratio is not just a FOV thing as you suggested.  It is a speed thing as well.  But the important thing to remember is speed is more related to aperture than focal ratio.  I shoot at F3 with my FSQ at 4", and I see no appreciable speed over F5.  BUT-give it an extra couple inches of aperture--like teh Epsilon, and speed goes way up.

3 hours ago, Rodd said:

Sorry--I meany focal ratio.  You are mixing points--I agree with that, but  my point is, an F5 scope will only have as wide a FOV as the sensor can accomodate.  So an f8 scope can produce a wider FOV image than an f5 scope if the F/8 scope has a larger sensor.  And, one can design a scope to have widely variable FOVs.  Not all f/5 scopes have the same FOV.  My point is focal ratio is not just a FOV thing as you suggested.  It is a speed thing as well.  But the important thing to remember is speed is more related to aperture than focal ratio.  I shoot at F3 with my FSQ at 4", and I see no appreciable speed over F5.  BUT-give it an extra couple inches of aperture--like teh Epsilon, and speed goes way 

Focal ratio is governed by focal length divided by aperture  end of.. so that's why f5 scopes don't have the same fov if either the fl or the aperture is different.. focal length gives you big the target will be, the aperture gives you the brightness as more photons are captured, if your imaging circle is bigger it can illuminate a bigger sensor.. 

Thought it was about microlensing anyway

 

[Rodd]

2 hours ago, newbie alert said:

Focal ratio is governed by focal length divided by aperture  end of.. so that's why f5 scopes don't have the same fov if either the fl or the aperture is different.. focal length gives you big the target will be, the aperture gives you the brightness as more photons are captured, if your imaging circle is bigger it can illuminate a bigger sensor.. 

Thought it was about microlensing anyway

 

You are right only if you are using a huge chip that covers the full FOV.  For most of us, FOV will be governed by teh sensor

[Rodd]

2 hours ago, Allinthehead said:

always thought your images were far superior with the Kaf sensor and looking at that one it's obvious. 

I wouldnt say that--some of the best of my images were taken with the ASiI1600 and TOA--but its probably more of a data quantity, "I am better at processing now" type thing.  We cant really compare the fSQ becuaseit was slightly miscolimated (soon to determine if it was fixed).  Its hard to say--I am a much better processor than I was.  But, I have decided--the STT-8300 with the tOA and the ASI 1600 with the DSQ and .6x reducer.  I got teh camera specifically for that scope and reducer as the STT-8300's self guiding filter wheel cant be used with it

[Rodd]

3 hours ago, newbie alert said:

Thought it was about microlensing anyway

The myth strikes again

[Rodd]

As promised-Here is my Alnitak--a deplorable mess!

[Merlin66]

Rodd,

interesting.....

I use the ASI 174 and the ASI 1600 for solar imaging. Obviously the solar disk is magnitudes (!) brighter than your stars....

Your results would indicate that the contrast with the ASI 1600 should be compromised due the micro lenses.

If, so I've never seen or been aware of it.

 

[Rodd]

25 minutes ago, Merlin66 said:

Rodd,

interesting.....

I use the ASI 174 and the ASI 1600 for solar imaging. Obviously the solar disk is magnitudes (!) brighter than your stars....

Your results would indicate that the contrast with the ASI 1600 should be compromised due the micro lenses.

If, so I've never seen or been aware of it.

 

It only happens with bright stars so I dont think overall contrast is reduced.  But who knows.  I am shooting atv.78 arcsec/pix, which probably robs me of signal (thats to high for a 5" scope, expecially in poor seeing

[Kaliska]

14 hours ago, newbie alert said:

I see that as a halo, not microlensing..

Are you using more than 1 filter ie a light pollution filter, is your filter as close to the sensor as it can be?

No secondary filters (LP) are used in my setup, nor any reducers as the TS100Q is a quadruplet. The ASI1600 is screwed straight into the back the ZWO filter wheel, so yes, its as close as it possibly can be. Once the images are stacked, it definately both halos and micro lensing.

[newbie alert]

5 hours ago, Kaliska said:

No secondary filters (LP) are used in my setup, nor any reducers as the TS100Q is a quadruplet. The ASI1600 is screwed straight into the back the ZWO filter wheel, so yes, its as close as it possibly can be. Once the images are stacked, it definately both halos and micro lensing.

I've seen this just last week with someone using a redcat  with a duallband filter, i know its a petzval design..not sure if that's anything like a quad

[Adam J]

12 hours ago, Rodd said:

As promised-Here is my Alnitak--a deplorable mess!

I would say that is as bad as I have ever seen it to be honest.....I dont get it that bad. You have clear separation of the pattern and two different sizes of reflection in the pattern indicating two surfaces in play. Which scope was this and what f-ratio?