For a while, motes had been appearing in my photos. At first I thought it was dust on either side of the objective (using refractors), but then it also appeared in Newt photos, so it had to be the sensor.
I tried the camera software vibration clean but that did nothing - obviously adherant crud (I suspect from when I accidentally scrapped the side of the drawtube with the camera nosepiece, chipping the black paint). I flipped open the flip mirror (properly of course) on the 5D MkII and CAREFULLY wiped over it with Bintel's UHTC cleaning fluid. IT improved it SOMEWHAT, but still some mote artifacts in photos (NOT apparent during day shots - only extreme contrast shots).
So, go at it again with thefluid, or is there a better way? I am VERY reluctant cleaning the sensor platen /IR filter...
Opinions and suggestions HIGHLY appreciated,as I am tired of having to stamp out the motes in photoshop
Not much - lessen them, but not remove them. Not visible until you stretch and start playing with contrast etc.
I use COMPLETE sets of darks, flats and biases.
It's hard to keep an imaging train 100% clean. Good flat fielding and dithering is the answer to your problem. Flat fielding if done correctly will get rid of all dust motes. Remember to shoot flats at the same time you shoot your lights. Each time.
I do - that's the thing. Minimum of 6, usually 10. I really think the sensor face MUST be cleaned, as I can even see bi-axial diffraction spikes on some bright stars near the field edge (where there is a smallish mote that seems to split the light somewhat like a hair would)
I have used my camera mini-vac in there a few times, and used the UHTC cleaning fluid - as I said, some improvement, but still apparent. The objective front and rear on my FL102 is perfectly clean, and there are NO other glass elements in the train after the objective (rarely if ever use a flattener with this scope)
I do - that's the thing. Minimum of 6, usually 10. I really think the sensor face MUST be cleaned, as I can even see bi-axial diffraction spikes on some bright stars near the field edge (where there is a smallish mote that seems to split the light somewhat like a hair would)
I have used my camera mini-vac in there a few times, and used the UHTC cleaning fluid - as I said, some improvement, but still apparent. The objective front and rear on my FL102 is perfectly clean, and there are NO other glass elements in the train after the objective (rarely if ever use a flattener with this scope)
Can you post a typical flat to have a peek at the dust?
Is this the full sensor? Flat fielding should take care of that no problem.
How do you make your master flat? Do you bias subtract prior to calibrate your light subs?
I let DSS make masters - well, at least that is what I believe it does? Should I be doing it manually???
The master dark for that flat series is very dark and uniform, which I guess is a good thing, and I assumed that DSS was creating them by dark and bias subtracting from the combined flats.
Or am I doing it all wrong? I have read 14,000 different iterations of how we should make darks, flats, biases, flat darks etc
Is this the full sensor? Flat fielding should take care of that no problem.
How do you make your master flat? Do you bias subtract prior to calibrate your light subs?
I let DSS make masters - well, at least that is what I believe it does? Should I be doing it manually???
The master dark for that flat series is very dark and uniform, which I guess is a good thing, and I assumed that DSS was creating them by dark and bias subtracting from the combined flats.
Or am I doing it all wrong? I have read 14,000 different iterations of how we should make darks, flats, biases, flat darks etc
I don't use DSS but for a flat to divide correctly into a light sub you need to have subtracted the bias from it or it won't scale correctly. This means you'll over or under correct your subs and you'll still see ghosts of dust motes.
The flats also need to be taken at the exact same focus you took your subs. Otherwise you'll still see ringing around where the dust spots used to be.
It is worth doing a little reading about it and try to do it manually. I mentioned dithering because obviously if a big/thick dust mote is on top of a star you'll never get that star light.
This is the thing - I don't like DSS, and always get BETTER results in MaxIM without doubt, but many times, for unknown reasons, MaxIM seems to reject my D,F,and B's and won't calibrate or use them. I have NO IDEA why, apart from maybe me shooting RAW (CR2), and MaxIM uses FIT?
When I have got MaxIM to use them (cannot remember how!) the images were 100% better than anything DSS ever did.
For a while, motes had been appearing in my photos. At first I thought it was dust on either side of the objective (using refractors), but then it also appeared in Newt photos, so it had to be the sensor.
I tried the camera software vibration clean but that did nothing - obviously adherant crud (I suspect from when I accidentally scrapped the side of the drawtube with the camera nosepiece, chipping the black paint). I flipped open the flip mirror (properly of course) on the 5D MkII and CAREFULLY wiped over it with Bintel's UHTC cleaning fluid. IT improved it SOMEWHAT, but still some mote artifacts in photos (NOT apparent during day shots - only extreme contrast shots).
So, go at it again with thefluid, or is there a better way? I am VERY reluctant cleaning the sensor platen /IR filter...
Opinions and suggestions HIGHLY appreciated,as I am tired of having to stamp out the motes in photoshop
I had a similar problem with my 450D. Only noticed it when imaging the Venus transit. There were a few "extra" sunspots. It took me a few goes with the fluid to clean the IR filter/sensor cover. I suspect that microscopic water droplets had got in at some stage and some mould spores had grown. I always try to avoid touching glass surfaces with anything ,but what else can you do?
