Couple days ago had a go with my scope. Just below M30, a bit to right from it found this ..... see image.
Conditions: Typical Sydney light polluted sky ( if lucky can see 4-6 stars). No UHC filter used.
Telescope N250 F4.8 + CANON EOS M ( unmodified i.e. IR filter in) at prime focus. FOV estimated 40 arc.min
Spectral capability: Sensor is CANON specifically developed for astrophotography ( same as on 6D camera). Photo-diodes are sensitive to any frequency from MHz to 300 GHz. Metallized mirror in the scope reflects any frequency, naturally this includes Xray and ?????
Picture is snipped (around 5 arc.min) from full frame. Any astrophysicists there with an idea ..... what the hell is it ?????
Regards Kris
Would probably have been easier to analyse a higher resolution image. My guess would be that the one on the right is a result of an internal reflection of the sharper image on the left, and that it was probably a point source of light that left that pattern on the sensor as it was moving relative the the camera (that could also mean telescope shaking too). How long was the exposure and are other objects in the image sharp?
As for CMOS sensitivity to EM spectrum, I would not think it was possible to pick much of anything outside of the visible spectrum, in particular that IR filter cuts frequencies below red light. Not sure about X-Rays though, I believe that sensitivity of CMOS used in DSLRs approaches zero below 300nm?
Thanks guys for ideas. Reflection ???? wonder how this is possible. Scope is one of SYNTA things, inside tube if unreflective coated. Who will fly drones after midnight ???
No cables ..... only guiding motors which are well below scope.
There was several shots ... all of them more/less same thing.
Exposure 6 sec. ISO 800. I guess full res photo will help to solve the mystery.
Thanks for the larger image. Coatings limit reflections, but do not eliminate them entirely.
One reason for this pattern could be marks/stains/water somewhere in the optical train. Try shooting again, with camera and everything aligned in the same way as before, and see if you get a similar pattern in the same part of the image.
My guess, they are stars oscillating with bad tracking. There are no other stars present in your images to indicate good tracking, and the shapes of each are identical, again indicating that they are still and your scope movement is the cause of the motion. I wouldn't be surprised if it was a wind gust.
My guess, they are stars oscillating with bad tracking. There are no other stars present in your images to indicate good tracking, and the shapes of each are identical, again indicating that they are still and your scope movement is the cause of the motion. I wouldn't be surprised if it was a wind gust.
That would explain the differences in colour in both patterns - nicely done. And once disturbed, the scope would take time (a few seconds?) to settle making stars oscillate in the image.
First ..... Tracking error - theoretical 0.0625 arc/sec
See image and zoom, how many galaxies are there??? and this is in Sydney "sky" and you have an idea about tracking stability. Area shown is somewhere around M30. https://goo.gl/photos/zVdLH11BB8rJjLwJ7
Telescope N250 F4.8 Canon EOS M, exposure times 5-8 sec, ISO 800
Pointing to target: RA 21:42:54 DE -23:11:31 FOV ~40"x1.1 deg ..... at least this is what was told the scope to go to.
When Moon is out of the way later tonight I may try video ... it will be like 150-250 images so some kind of stacker can be used.
To be honest, your first image has strongly elongated stars in only a 5-8 second exposure, indicating poor guiding. Definitely not 0.0625 arcseconds per...?
It might also be something in the sensor itself, since this object is sharp in relation to the background.
More images could potentially help in identifying the cause.
At 5-8 seconds there should be some or even a considerably number of stars present in the images. I don't think it is a tracking error for some of those just because nothing but those things is showing. This makes me really think it is an internal reflection, possibly on the glass plate or silicon surface?
My guess, they are stars oscillating with bad tracking. There are no other stars present in your images to indicate good tracking, and the shapes of each are identical, again indicating that they are still and your scope movement is the cause of the motion. I wouldn't be surprised if it was a wind gust.
To be honest, your first image has strongly elongated stars in only a 5-8 second exposure, indicating poor guiding. Definitely not 0.0625 arcseconds per...?
It might also be something in the sensor itself, since this object is sharp in relation to the background.
More images could potentially help in identifying the cause.
Lets keep the investigation going
There are links to more images taken few days later.
I am talking about long term tracking, positional update is 1 per 1 time second and this is with accuracy +/- 0.065 arcsec.per update. Mechanical "back lash" becomes stable after a couple of seconds.
There are links to more images taken few days later.
I am talking about long term tracking, positional update is 1 per 1 time second and this is with accuracy +/- 0.065 arcsec.per update. Mechanical "back lash" becomes stable after a couple of seconds.
Regards K.
If you don't want to listen to the answer that people give you, then don't post asking. I am telling you, they are stars. Quoting some tracking figure like 0.065 arc seconds means absolutely nothing. I will tell you right now that if you think your tracking is that good, you are wrong. If they are indeed some form of nebulous discovery, then kindly explain why these two images appear to be the same objects, but spread out slightly differently.
The answer is, they are stars, and your tracking is variable.
If you don't want to listen to the answer that people give you, then don't post asking. I am telling you, they are stars. Quoting some tracking figure like 0.065 arc seconds means absolutely nothing. I will tell you right now that if you think your tracking is that good, you are wrong. If they are indeed some form of nebulous discovery, then kindly explain why these two images appear to be the same objects, but spread out slightly differently.
The answer is, they are stars, and your tracking is variable.
feel free to add a drop box link of the actual original raw and unaltered file ... till then nothing can be added to what has generously been said.
i suspect there is nothing wrong with the equipment but its application and that is something we may be able to help you with - more details to that effect would aid in achieving this.
feel free to add a drop box link of the actual original raw and unaltered file ... till then nothing can be added to what has generously been said.
i suspect there is nothing wrong with the equipment but its application and that is something we may be able to help you with - more details to that effect would aid in achieving this.
regards
Ha .... so far no one was talking about seeing. I thing this is most likely suspect.
Should you have Pix-Insight software and willing to analyze images you may find more likable answers. I used only uraf .... may be buying one day Pix_Insight but with sky quality in Sydeny it is rather pointless.
And one image giving an idea about my optical instruments .... pretty good. https://goo.gl/photos/dsQneEbTEKKbYqX5A
naturally one needs to consider seeing at time of observation. Sydney is almost constantly in "earth quake" see geophysical survey for area .... amplitue much higher than photons vibration amplitude and 0,4 arc.sec optics resolution, largely ignored by amateur astronomers.
Thanks for trying to have professional look at my query.
1. each image shown is grossly out of focus
2. the "good" image showing stars has very poor tracking - there is elongation across the entire field. Stars should look like round points of light.
3. there IS internal reflection to some degree evident in some of the images
4. the "odd object" not only duplicates itself once, but in another shot, it is shown 4 times, in varying degrees of fade.
5. Possibly it would seem the scope is also out of collimation to some extent
I shoot my images from extreme light pollution and have no appreciable problems. Also, MANY MANY imagers in Sydney do not seem to suffer from any geological instability!!!
Next we will be seeing insects on the moon again... aye carumba!
I would seriously suggest LISTENING to what is being suggested and generously offered and not quoting erroneous figures and pseudo-science factoids.
