Cameras without inherent Newton's Rings

[Macavity]

As the sun begins to clear the observatory walls finally! <ahem>
... a (this!) young man's fancy turns again to H-Alpha imaging?

Previously, I have been a devotee of ZWO (120MM) cameras,
but I get a tad tired of "drifting" the image and I'm not overly 
keen of introducing a significant dog-leg into the optical path! 

I seem to have got the idea that IMAGING SOURCE cameras
are inherently  FREE from Newtons Rings? Uhm, Is this true?????

IF SO, I note e.g. (Aside from FLO's excellent range) such
cameras (smaller pixels, larger chips) occasionally come up 
on EBAY for modest prices... OK they are used, but... 

AND if this were  to solve the rather BASIC problem...

[Davey-T]

Not that simple probably, if I  use my Quark and PGBfly + .5f/r it has no Newton rings, if I use it without the focal reducer it has Newton rings, if I use the PGBfly in the LS60DS it has no Newton rings.

Dave

[riklaunim]

Just use a camera that do not use a Micron/Aptina sensor (like ASI120). Old TIS cameras are old and rather not worth it - there are modern cameras with Sony IMX sensors

[Davey-T]

24 minutes ago, riklaunim said:

Just use a camera that do not use a Micron/Aptina sensor (like ASI120). Old TIS cameras are old and rather not worth it - there are modern cameras with Sony IMX sensors

My PGBfly Sony ICX sensor get NRs, don't know the difference from IMX sensor.

Dave

[Ibbo!]

My AS120 is terrible no ammount of tilt seems to help

My Blackfly IMX249 is fine - but know other people have problems

my DMK was fine without powermate- was happy with images just too small a chip

My DMK21 was also fine too small a chip

 

all with Lunt 60mm

[riklaunim]

The difference between Micron and other sensors is that in most cases for it - the Newton rings were causes by the sensor itself (it cover glass) in a way that tilting would not affect it. With other cameras it still can happen that you get them but it's not a problem with the sensor itself and in general - tilting it fixes the problem.

[Pete Presland]

I use nothing else, other than the DMK21AU618. Not really had any problems with the rings.

[Macavity]

17 hours ago, Davey-T said:

Not that simple probably...

Therein capturing the essential(s) of it, Eh Dave? 

I now know (with significant aid from fellow Solarites!) how
to produce a passable  full-disk sol image from my Lunt 50.

Ye cannae change the Laws of Physics,  Cap'n?  

It is clear that the source of NR's is internal to the CHIP?
And, of course, the specific "angles of incidence" etc. etc.
Also explaining why mere Barlowing changes things too!

Not UN-CONTENT(!) with continuing to "drift" etc. I still
hanker after "closer" images of solar features though.

The right Barlow, the right drift speed. Still determined.
(I am) grateful for the "cutting edge technology" etc.

Thanks (as ever) for some good ideas re. cameras!

[Davey-T]

35 minutes ago, Macavity said:

Therein capturing the essential(s) of it, Eh Dave? 

I now know (with significant aid from fellow Solarites!) how
to produce a passable  full-disk sol image from my Lunt 50.

Ye cannae change the Laws of Physics,  Cap'n?  

It is clear that the source of NR's is internal to the CHIP?
And, of course, the specific "angles of incidence" etc. etc.
Also explaining why mere Barlowing changes things too!

Not UN-CONTENT(!) with continuing to "drift" etc. I still
hanker after "closer" images of solar features though.

The right Barlow, the right drift speed. Still determined.
(I am) grateful for the "cutting edge technology" etc.

Thanks (as ever) for some good ideas re. cameras!

Have to buy a quark then 

Dave

[Ewan]

My DMK ""618 never suffered at all, ever, only reason I went with my IMX174 was more fov & way faster frame rate.

[Macavity]

On 2/16/2017 at 11:17, Davey-T said:

Have to buy a quark then 

Nice idea... And likely to remain so! lol. TBH the idea of a "Frankenscope" has always appealed.
Find an F7 scope and use my existing Etalon... Buy an ERF etc. My Lunt50 has a "600" BF, but
doesn't allow very much room for a BIG upgrade? I do understand about ERF's now though! 



Trouble with H-Alpha is that nothing is really an "upgrade"? You just pay the SAME again... 

[Zakalwe]

On 15/02/2017 at 17:09, riklaunim said:

Just use a camera that do not use a Micron/Aptina sensor (like ASI120). Old TIS cameras are old and rather not worth it - there are modern cameras with Sony IMX sensors

Its not as simple as that. Both my ASI 1600 Cool (Panasonic MN34230ALJ sensor) and ASI 174 (Sony Exmor sensor) exhibit NRs. I think that its more to do with CMOS sensors. It can be hit and miss and very dependant on the individual setup as some people using very similar setups to me do not appear to get them.

A tilt adapter sorts them though and does not appear to have any effect on focus. I wouldn't have a problem with recommending an adapter. Its certainly much easier than having to drift the image.

[riklaunim]

On 18.02.2017 at 11:45, Zakalwe said:

A tilt adapter sorts them though and does not appear to have any effect on focus. I wouldn't have a problem with recommending an adapter. Its certainly much easier than having to drift the image.

Newton rings can show up with ANY camera. What's specific about Micron sensors is that their Newton rings DO NOT vanish with tilting (if the sensor itself is giving them).

QHY even posted some R&D on this topic long time ago and they blamed the cover glass of the sensor.