camera dramarama

[TiffsAndAstro]

1 hour ago, PhilB61 said:

I see that Astronomiser UK still advertise astro modding the 600D for £95 which includes return postage. I don't have any experience of them or know if the site is still current but they certainly had good comments regarding their modding services as far back as 2014 on this forum, there contact details are on the website. Might be a good intermediate step whilst you gather more funds to get a cooled astro camera in the future?

im looking a the site atm, and £95 is a good deal, but it doesn't help with my rotation or uv/ir cut or nb filter swapping

i'd rather keep the £100+ (postage there/back) and put it towards a proper astro camera, rotator and filter drawer.

[TiffsAndAstro]

1 hour ago, Vroobel said:

 

I shouldn't do it... 🤫

My Canon 6D was modified there and I'm happy with it.

 

your results prove how good it is, but i have the filter issue and rotation issue to also deal with and a modded dslr won't help me with that

[TiffsAndAstro]

apologies for 4 pages on "i need help buying a cheap astro cam" i wasn't expecting to need this much help and advice on what i thought would be a relatively straightforward thing.

sv605cc uses the imx533 sensor and includes what im guessing is all the bits i need from the flattener back, to get back focus. 

https://www.svbony.com/sv605cc-camera/#F9198K

doesnt seem to include a power supply, of course it doesnt.

[TiffsAndAstro]

Is there a power extension lead I could attach to my mount power supply so it could still power my mount and then run up to sv605cc? Ideally via a second extension to that lead so I detach it from stuff more easily?

Would it be able to supply enough juice to both?

https://www.firstlightoptics.com/batteries-powerpacks/lynx-astro-12v-dc-5amp-low-noise-mains-power-supply.html

Some sort of t junction, then then one more shortish extension lead?

If not, I guess I could try the mount on rechargeable batteries

 

Edited June 12 by TiffsAndAstro

[Elp]

3 hours ago, TiffsAndAstro said:

Would it be able to supply enough juice to both?

Should do. I've got that one. It has powered my airs, then power to the mounts, cooled cameras etc perfectly fine. Just ensure they're protected from dew when it's cold (I cover them loosely with something like a sheet of cardboard) and leave them on top of another piece on the floor.

[TiffsAndAstro]

5 minutes ago, Elp said:

Should do. I've got that one. It has powered my airs, then power to the mounts, cooled cameras etc perfectly fine. Just ensure they're protected from dew when it's cold (I cover them loosely with something like a sheet of cardboard) and leave them on top of another piece on the floor.

cool ty ill look around for a t junction and stuff. would mean almost one less wire

[Elp]

If you want to future proof get a 10A one, or do what @Vroobel did with Xbox PSUs (some wire conversion is needed though I believe).

[TiffsAndAstro]

31 minutes ago, Elp said:

If you want to future proof get a 10A one, or do what @Vroobel did with Xbox PSUs (some wire conversion is needed though I believe).

not keen on eletrickery i guess ill see how i current one gets on powering both items if i can find a suitable t junction etc. 

and some cardboard i might even stretch it to premium cardboard.

[900SL]

The 533 is the best camera for starters.

Square sensor minimises effects of tilt, vignetting, field flatness etc. 

Low power requirements, low noise, 3.75 micron pixels have good SNR capture and more forgiving of tracking errors as usually undersampled a touch.

Sensor uses 1.25" filters and saves a packet in a mono rig

I have both 533MC and 533MM and no intention to change either.

 

[TiffsAndAstro]

3 hours ago, 900SL said:

The 533 is the best camera for starters.

Square sensor minimises effects of tilt, vignetting, field flatness etc. 

Low power requirements, low noise, 3.75 micron pixels have good SNR capture and more forgiving of tracking errors as usually undersampled a touch.

Sensor uses 1.25" filters and saves a packet in a mono rig

I have both 533MC and 533MM and no intention to change either.

 

So good you bought it twice? (Sort of). So far I haven't seen any bad comments and yours have just confirmed for me I should go for it over a 585 even with the added cost.

I had a really clear and great reply from Nina at svbony clearing almost everything up.

I just hope the svbony version compares reasonably well to the competitions version. Only one way to find out.

I'll let forum know how I get on

[TiffsAndAstro]

i think i'll skip svbony's solitary rotator offer as i think its for a specific telescope. m68 is pretty rare.

does anyone know if i get a  astro essentials one from flo it should still work with my gear and allow me to get back focus? seems a decent range of spacers included with the svbony?  ill email them and ask i guess. also a rotator doesn't seem as vital for a square sensor. 

https://www.svbony.com/sv605cc-camera/#F9198K-F9127A-W9184A

is there anything obvious i might have missed to check on? other adapters or anything?

another slight update, svbony been replying to a few questions to me this morning and im now very impressed with their answers and speed of response. they also told me not to buy today and wait until tomorrow when the price will drop further

im going to have to bite the bullet and see what happens, i think

Edited June 13 by TiffsAndAstro

[900SL]

Assume you are getting an uncooled version. Just be aware, that if you shoot dual narrowband on OSC, you might be exposing for several minutes per sub. Check out the thermal performance of the 533 chip if uncooled. You might find your subs quite noisy and difficult to calibrate with matching darks

[TiffsAndAstro]

56 minutes ago, 900SL said:

Assume you are getting an uncooled version. Just be aware, that if you shoot dual narrowband on OSC, you might be exposing for several minutes per sub. Check out the thermal performance of the 533 chip if uncooled. You might find your subs quite noisy and difficult to calibrate with matching darks

Nah I'm going for the tec cooled one. Seems a relative bargain if there is such a thing.

Will probably have to sort a rotator separately but like you said with a square sensor its less of an immediate issue. Getting the filter drawer and UV/ir cut filter with it.

https://www.svbony.com/sv605cc-camera/#F9198K-F9127A-W9184A

 

 

 

[Elp]

2 hours ago, 900SL said:

Assume you are getting an uncooled version. Just be aware, that if you shoot dual narrowband on OSC, you might be exposing for several minutes per sub. Check out the thermal performance of the 533 chip if uncooled. You might find your subs quite noisy and difficult to calibrate with matching darks

I normally do 60s with any camera, cooled or uncooled. Uncooled for DSO I've used 485/183/294, all work fine being uncooled (other than the 294 colour pattern issue).

[900SL]

4 hours ago, Elp said:

I normally do 60s with any camera, cooled or uncooled. Uncooled for DSO I've used 485/183/294, all work fine being uncooled (other than the 294 colour pattern issue).

60s using dual narrowband filters?  I had to shoot 3 to 5 minute subs with the IDAS NBZ / Antlia ALP-T

[TiffsAndAstro]

1 hour ago, 900SL said:

60s using dual narrowband filters?  I had to shoot 3 to 5 minute subs with the IDAS NBZ / Antlia ALP-T

Can I ask say why one 5 mins sub is better than five 1 min subs? This seems to be quite a topic on YouTube.

I would imagine longer means feinter details captured, but if stacking multiple images this might not be the case? Maybe if stacking was additive, but that would just result in blown out stacking results?

[happy-kat]

if I could do 5 minute subs I might get 3 or more plane trails

[Elp]

1 hour ago, 900SL said:

60s using dual narrowband filters?  I had to shoot 3 to 5 minute subs with the IDAS NBZ / Antlia ALP-T

Probably because most of the time I'm imaging F2-3. But I have also done 60s with a modded 600D and lextreme results of which are up earlier this thread, that was at F5.6. I've also done SHO narrowband with my Z61 60s too. Total time makes all the difference.

[Elp]

32 minutes ago, TiffsAndAstro said:

Can I ask say why one 5 mins sub is better than five 1 min subs?

I think it stems from the days of CCD imaging and people still think it applies to CMOS which is more sensitive I believe. The benefit is you get more pixel response up to the full well depth limit and you get less read noise in the stack if you're taking less longer subs Vs more read noise in more shorter subs if total imaging time is equal between them.

[900SL]

47 minutes ago, TiffsAndAstro said:

Can I ask say why one 5 mins sub is better than five 1 min subs? This seems to be quite a topic on YouTube.

I would imagine longer means feinter details captured, but if stacking multiple images this might not be the case? Maybe if stacking was additive, but that would just result in blown out stacking results?

 

[900SL]

20 minutes ago, Elp said:

I think it stems from the days of CCD imaging and people still think it applies to CMOS which is more sensitive I believe. The benefit is you get more pixel response up to the full well depth limit and you get less read noise in the stack if you're taking less longer subs Vs more read noise in more shorter subs if total imaging time is equal between them.

It's about signal. If you expose too short, you will bury the signal in the noise, and no amount of stacking will recover it. That TAIC youtube is quite interesting. It appears somewhat at odds with Dr Glovers method. 

I personally determine exposure by doing a test sub and checking mean background ADU. I've found that I need anything from three to six minutes with a dual narrowband / 533 MC to get a high enough ADU 

[Elp]

I always do a few previews prior to running a plan to determine a nice sub time. As you say, no point in taking images if you can't see the signal.

[TiffsAndAstro]

26 minutes ago, 900SL said:

It's about signal. If you expose too short, you will bury the signal in the noise, and no amount of stacking will recover it. That TAIC youtube is quite interesting. It appears somewhat at odds with Dr Glovers method. 

I personally determine exposure by doing a test sub and checking mean background ADU. I've found that I need anything from three to six minutes with a dual narrowband / 533 MC to get a high enough ADU 

still watching video it will take a while.

i did see a cuiv video using sharp cap info via nina to determine optimum exposure lengths and they came out at like 7 seconds or something silly. something about the only thing that really matters is swamping read noise. but im hoping your video explains this and related stuff really works and it looks like it will. many bullet points during intro

main thing i can't get my head around though is if wanted signal is directly proportional to exposure time, how would a longer exposure help as long as its long enough to make the wanted signal greater than signal that is not directly proportional to exposure time. i doubt im explaining that too well, sorry.  

back in at least 1hr 30mins

i lied. a better way to explain my question might be. even in bortal 9, the photons per sec from light pollution cannot be greater than the photons per second from a target source, else the target source could never be imaged. this i guess isn't true for the specific wavelengths used in narrow band (as light pollution is not strong in those wavelengths), but might be in broadband?

Edited June 13 by TiffsAndAstro

[TiffsAndAstro]

****after watching this excellent video*** this is such a good video in so many ways (but also horrible in its implications) 

i can see why you linked it. no pressure or expectations  on answering any/all the stuff i ask below. it would be asking a lot of anyone apart from maybe the guy in the video  

what temperature do you cool your 533 sensor to? because for me with bortle6 and f5.8 scope i should be able to set the imx533 to just say +2 (or even higher) centergrade and avoid ar glass window frosting if the svbony doesn't have a ar glass window heater (which is doubt it does) and swamp the read noise with just the light pollution? then i can have a single library of darks as its unlikely to be more than 32 centegrade at night in the nw uk

there is talk of future sensors being able to read whatever pixels you want whenever you want. there needs to be software that can recognise (for example) the pixels of a galactic core and read them out more often then those pixels in the wisps around the edge and can get best shot noise per pixel no matter if imaging a bright or much less bright area of a target? also the sensor's outer pixels could be used for guiding?

is there an equivalent or another name for "PSF signal weight" when stacking in siril because its options don't inlcude that phrase. maybe "wighted fwhm" or "noise"?

also thinking about dual narrowband and osc, i think (im definately not sure as i doubt i've compared  enough good images to really get a good understanding of what i personally like) i prefer broadband 'colour' over what appears to me to be a narrow range of reds for Ha and even smaller range of greenyblues for O and nit much else?. i don't mean stars i mean in nebulosity. its why i've asked here in the past if the colour in my one and a half 'decent' images is really just stretched noise resulting in colour. if its not, and its 'real' colour from the target, why don't other people seem to like it as i do? 

how is he measuring his diminishing returns in snr/number of subs as he continues to gather more data? is there a way in Nina?

not sure how this can be used for the broadband ill be doing, even if/when i get dnb filter. not sure if  lrgb directly equals osc. but then im not even sure i can combine osc with Ha + Oiii into one final result.

how many exposures are required for ground based images to rival the snr of hubble and reveal feinter detail?

its interesting that both lucamatico and cuiv both seemed to conclude that sub times don't really matter, but because their tests are in bortle 6/7 and bortle9 their tests wouldn't show much difference, but there would be in lower bortle areas. this is such a good video.

apologies in advance, but as you have a 533 colour sensor, soon after mine arrives (if i do get it) i'll be asking you what gain (101?) what offset (+70?) and stuff like that. sorry

so to sum up what is my ideal exposure length? (lol sorry couldn't resist) seems longer exposures won't hurt snr, but have disadvantages for planes, wind, blips in guiding. im not sure if there can ever be a correct answer for this question as only so many of the factors that influence it can be knowns. if i live near an airport, the likely hood of planes is higher which would suggest shorter exposures. but not too short

did the video guy turn this into an online tool to so others can more calculate all this? its really weird that i thought i got better results with my dslr at iso 200 (accidentally) than the recommended 800 but set it back to 800 because that had the best noise response. i was doing 180 sec subs. a while back. i think i'd have to do as guy says lower than unity gain balanced against the amount of bright/darker of the areas of my target and balance that with my gears ability to do longer exposures and aircraft frequency?

i like how the two 'presenters' towards the end clearly didn't understand the point the main guy was making lol

[TiffsAndAstro]

2 hours ago, 900SL said:

It's about signal. If you expose too short, you will bury the signal in the noise, and no amount of stacking will recover it. That TAIC youtube is quite interesting. It appears somewhat at odds with Dr Glovers method. 

I personally determine exposure by doing a test sub and checking mean background ADU. I've found that I need anything from three to six minutes with a dual narrowband / 533 MC to get a high enough ADU 

the lower your bortle,  the better it is to do longer exposures it seems. or at least lower bortle gets the most out of longer exposures?