mono cameras

[brrttpaul]

So I was just wondering what would be the best way for a beginner to start with the use of filter wheels etc and LRGB with HA  SII and OII . What would be the best way to start offregardless of whatprogramme you are using, everything the same exposure length? dont touch the narrow band filters untill you get used to taking LRGB? stick to same binning, just use bias and flats? anything else?

[swag72]

My first question would be what exposure length can you achieve? NB will benefit from longer subs for sure. 

I'd start off with a nice simple mono Ha image, with subs as long as you can get. Then if you can get the OIII and SII, using the same length subs. I would say that at the moment keep it simple and use 1x1 bin for all the exposures.... definitely take bias, flats and darks too.

Cygnus is starting to come up at a decent time now, so there's going to be loads of NB targets about for you to practise on. Focusing is a little more tricky with NB ... do you use manual or auto focus?

[brrttpaul]

now thats interesting as I am all set up on a trial run (been building the obsy all done except waiting for the wheels to arrive so just moving it by hand ATM) . I would have thought just LRGB  and leave the narrow band alone (even though I,m dying to try out narrow band), I use manual focus but do use a BAT mask,  I dont want to mess about with darks atm and someone on here suggested just taking Bias so will go with that for the time being (along with flats). The last week I have been trying with PI but ended up with loads of folders and started losing where I was, I,m sure once I get a workflow going it will become much easier. I did do a test run last week mainly because I wanted to try out plate solving and get my guiding camera set up. I am hoping that tonight I get my alignment sorted my guide cam (PHD2) running smoothly) and the plate solving seen to. The plate solving is the most important ATM for me as when I used astrotortilla i picked a target and slewed it took a shot then reslewed so the target was dead centre, couldnt be easier but with SGPRO it works different and still trying to get around it

[steppenwolf]

If you are dying to give narrowband a try, there is no reason why you shouldn't and keep in mind that you can capture some great Ha data even under full moon conditions - I am currently in an imaging session taking 1800 second exposures in Cygnus despite the very bright Moon!

When the Moon has gone, you can then add some OIII and SII to your Ha data to produce a colour image.

Again, when the Moon is gone, you can also have a go at an LRGB image but as Sara has suggested, don't complicate matters by binning the RGB 2 x 2 - capture all the data binned 1 x 1.

[brrttpaul]

oh lucky you said that as I just set up a sequence that was Ha plus OII and SII, ATM i am messing with plate solving, its doing it both blind synch and solve and sync, but it just saya solved it dont reslew to lets say Vega as I am pointing at it now (well just off it) but with astrotortilla it would centre vega  EDIT scarp that last comment as vega was way to th right out of curiosity i right clicked and saw (centre scope here) HAPPY

[brrttpaul]

Well I was making good progress last night just couldnt image as it clouded over then eventually started raining, the plate solve Im resonably happy with but still wont centre bang in the middle ( its only off a few mm)  why I dont know but no biggy ATM. Once I get my drift alignment done with PHD I should be good to go, It will just be a matter of learning the different exposure times then and getting a good workflow going

[iapa]

3 hours ago, brrttpaul said:

Well I was making good progress last night just couldnt image as it clouded over then eventually started raining, the plate solve Im resonably happy with but still wont centre bang in the middle ( its only off a few mm)  why I dont know but no biggy ATM. Once I get my drift alignment done with PHD I should be good to go, It will just be a matter of learning the different exposure times then and getting a good workflow going

I had a 'problem' with SGPro slewing and centring to target. I would start the sequence, scope would slew, capture, plate solve but never get any closer than nnn pixels.

I finally tracked it down to the mount having moved whilst unused. Check PA and it was off by a goodly (badly) amount. Corrected that and entering was spot on again.

[brrttpaul]

could well be that then as all i done was plonk it back on its pier and tightened up the bolts, TBH I didnt think I would get as far as I did last night and now the scopes there permanent I will have more oppurtunities to get it bang on. I could never go back to the tripod after a permanent set up its just so much quicker and easier

[iapa]

21 minutes ago, brrttpaul said:

could well be that then as all i done was plonk it back on its pier and tightened up the bolts, TBH I didnt think I would get as far as I did last night and now the scopes there permanent I will have more oppurtunities to get it bang on. I could never go back to the tripod after a permanent set up its just so much quicker and easier

still planning where to put mine. Hope to have it in place tho' by October at the latest.

I hadn't expected the mount to move as it's about 100lb, but PA being off showed it had

In the mean time reading up on best exposure times for LRGB with a CMOS rather than CCD camera.

Some say more shorter exposures. But, when I see 1 min exposure as short, and 10m also short with 30m getting to be long, not sure where to try first

[brrttpaul]

I know exactly what you mean, im hoping to be all setup by middle of Aug thats my goal, the exposures I have been looking at on astrobin but they do tend to vary in range quite a lot. I,m pretty much good to go its the processing where I will come unstuck I think and thats why I will be only doing Bias and flats untill I get used to it. What I did notice in Maxim if I stack my LRGB the finished sub is in colour (I save this and then open it up in PI). But I want to try and do it in PI just when I stack them it still looks in B&W (I know its colour from the stretch screen just struggling to convert it to colour.

[ollypenrice]

I'm always amazed by the plethora of IT solutions in fashion. They are very good when they are set up and working but that, in itself, is a task to be mastered. Just for the record, I don't plate solve and I don't autofocus. (I don't take the camera on and off either and I only rotate it if I really have to.) I focus on my first alignment star using a B mask and then use a final tweak in FWHM once onto the target. I then give this a check every 90 minutes or so. For framing I use marker stars or just look at obvious star patterns around the edges of the picture. A lot of this software strikes me as being a solution in search of a problem.

I really liked Sara's answer to your question because it went against the orthodoxy and struck me as being dead right. The easiest way to take a first great image is to shoot an emission nebula in Ha. The hard parts are done for you by the filter. That's to say, all skyglow will be subdued, you'll get a pretty even background sky, and your stars will be small. You'll also get strong local contrasts.  In LRGB processing those are all the hard hard bits.

Olly

[brrttpaul]

well I am glad you cleared that up for me lol.  Sometimes  I do wonder.  I can lay 1000 bricks a day perfect  dont even bother with a level as i use profiles and gauge rods, I know what intrados and entrados are and voisoirs, english bond flemish bond, a stepped buttress and a flying buttress, and if anyone asked me how to build something or go about something I would gladly tell them how to go about it in laymans terms. its very easy when you know how its when you dont know it becomes difficult or confusing. I really am very sorry if it sounds blunt as its not meant to be but if someone asked me how to lay bricks I wouldnt say mixing the compo is the easy bit laying them is the hard bit I would tell them exactly what they need and how to go about it. now I will duck for cover .

[Davey-T]

I'm a bit in the Olly camp here, although I do use plate solving on one of three mounts, it's quite easy to find and frame the target yourself.

The FWHM / HFD in Maxim is fine for focusing especially if you stick to one filter.

If just starting out I think you should walk before you run, so just take single subs in Maxim rather than set up complicated autorun sequences which can be pretty confusing in themselves, apart from the fact in this wonderful UK climate one filter per night is generally enough.

Let Maxim grade and stack your best subs on a single filter including RGB etc if you take some then you can combine them in P'Shop or PI, no reason not to do an RGB stack in Maxim as well to see what it looks like as it only takes a short time.

Getting guiding working and taking 10 minute subs HA subs is quite enough at this time of year, by the time Autumn arrives you'll be a dab hand and ready for some all nighters.

After a few frosty nights you'll no doubt want to get fully automated and hide indoors although it's never appealed to me as I'm retired and don't have to be up early for work I'm happy staying out stargazing while the rig downloads the subs.

Dave

[brrttpaul]

I do agree, I do use Maxim for the stacking if I fail (which I did with PI) its just I wanted to try and keep everything to one or two programmes (in this case sgpro and PI). Heres where Im at my scope/camera/laptop is permanently set up, the roof comes off just not on wheels (waiting for them to arrive hopefully today). I did manage to do a polar alignment last night at last and I also used the sharpcap polar alignment tool to check and im pretty much spot on so alls good to go. I got eqmod running lovely plus sgpro and phd2 (though for some reason I dont think its talking to sgpro but I can live with that atm). I have also used the BAT mask for my focus so thats ok atm.  the processing on the other hand is  a different kettle of fish, tried making a master flat the other night cant remember exactly at what stage now but it asked for a master dark?? so what master dark would I use ? a 30 sec dark a 60 sec?, I wernt expecting that TBH. I cant do nothing untill I get a clear sky but did do a few master darks though only BIN 1x1 not 2x2 yet. Someone suggested on here dont use darks just flats and bias so I am going along with that for the moment (if I ever get the chance). as a side note if I do image in HA (which I am planning) do i take LUM also? or just the HA.

[alacant]

1 hour ago, brrttpaul said:

dont use darks just flats and bias

IIRC, that was for certain dslr sensors; it's certainly true for my 700d. HTH.

Good luck with the mono.  

[swag72]

I do all my calibration with Maxim... I think it works well. If you know how Maxim works then I'd stick with it for now. It won't affect your end image I'm sure.

[brrttpaul]

I just find Maxim so easy as everythings in one folder and it sorts them all out, I know I,m a pest and keep banging on but another thing I cant get my head around is gain etc, why once you connect your camera in sgpro cant you change it without first disconnecting the camera then going to settings change there then reconnecting?  would be a lot easier if you could change it without disconnecting it. Reason Im asking is I have seen some where the lum is one thing the RGB is another etc etc. just curious thats all its not a biggy

[ollypenrice]

9 hours ago, brrttpaul said:

well I am glad you cleared that up for me lol.  Sometimes  I do wonder.  I can lay 1000 bricks a day perfect  dont even bother with a level as i use profiles and gauge rods, I know what intrados and entrados are and voisoirs, english bond flemish bond, a stepped buttress and a flying buttress, and if anyone asked me how to build something or go about something I would gladly tell them how to go about it in laymans terms. its very easy when you know how its when you dont know it becomes difficult or confusing. I really am very sorry if it sounds blunt as its not meant to be but if someone asked me how to lay bricks I wouldnt say mixing the compo is the easy bit laying them is the hard bit I would tell them exactly what they need and how to go about it. now I will duck for cover .

Was this in response to my post? I'm not sure what point you're making.

I was agreeing with Sara that, assuming you're using a mono camera, you'll find it easier to get a good Ha image than an equally good image through any other filter. I tried to give an explanation of why that is. Sorry if it wasn't helpful.

I'd just pick bright Ha target, sort your guiding as best you can, then take a run of 10 to 15 minute Ha subs. If you can get the mount to dither between subs all the better. If not, don't worry. Shoot flats, darks and bias. I'd try stacking both with and without darks to see which gives the best result.

Olly

[steppenwolf]

3 hours ago, brrttpaul said:

tried making a master flat the other night cant remember exactly at what stage now but it asked for a master dark?? so what master dark would I use ? a 30 sec dark a 60 sec?, I wernt expecting that TBH.

MaxIm most likely asked you to do this because under the 'Advanced Tab' on the Set Calibration window you have ticked 'Dark Subtract Flats'. Unless your Flat files are long exposure (20 seconds or more) then you will not need to dark subtract them.

3 hours ago, brrttpaul said:

as a side note if I do image in HA (which I am planning) do i take LUM also? or just the HA.

Just Ha - Luminance is only a consideration if you are capturing RGB data and our (Olly, Sara and I) suggestion is that you start by capturing Ha data as that removes much of the complexity that LRGB introduces because of sky gradients so your first images will have a much greater chance of success.

[brrttpaul]

1 hour ago, ollypenrice said:

Was this in response to my post? I'm not sure what point you're making.

I was agreeing with Sara that, assuming you're using a mono camera, you'll find it easier to get a good Ha image than an equally good image through any other filter. I tried to give an explanation of why that is. Sorry if it wasn't helpful.

I'd just pick bright Ha target, sort your guiding as best you can, then take a run of 10 to 15 minute Ha subs. If you can get the mount to dither between subs all the better. If not, don't worry. Shoot flats, darks and bias. I'd try stacking both with and without darks to see which gives the best result.

Olly

It was a sort of half hearted frustrating type of response TBH, I was trying to make an analogy of what its like sometimes  and probably didnt do a good job on it. I do apologise if I have offended you in any way

[brrttpaul]

27 minutes ago, steppenwolf said:

MaxIm most likely asked you to do this because under the 'Advanced Tab' on the Set Calibration window you have ticked 'Dark Subtract Flats'. Unless your Flat files are long exposure (20 seconds or more) then you will not need to dark subtract them.

Just Ha - Luminance is only a consideration if you are capturing RGB data and our (Olly, Sara and I) suggestion is that you start by capturing Ha data as that removes much of the complexity that LRGB introduces because of sky gradients so your first images will have a much greater chance of success.

sorry I wernt specific this was in PI not Maxim, in maxim i get no problems its in PI I struggle but the biggest problem is lack of oppurtunities due to constant cloud cover . which is so frustrating sometimes

[Davey-T]

To be honest Paul if you know Maxim I'd stick with it until you get everything else working and produce some images, do you have P'Shop ? if not Gimp will do.

Plenty of top class images have been produced without a whiff of PI  it's not some magic bullet to make processing easy.

Once you achieve this you can experiment with the confusing PI interface.

Dave

[swag72]

2 minutes ago, Davey-T said:

To be honest Paul if you know Maxim I'd stick with it until you get everything else working and produce some images, do you have P'Shop ? if not Gimp will do.

Plenty of top class images have been produced without a whiff of PI  it's not some magic bullet to make processing easy.

Once you achieve this you can experiment with the confusing PI interface.

Dave

Well said Dave....... 

[brrttpaul]

Cheers dave, I think for the time being I will stack and calibrate with maxim and process the image with PI as once I have a colour photo I can get around pixinsight ok ( I found that quite easy tbh) the stumbling block was acctually preprocessing with PI, but yes totally agree with you I will stick with maxim to do my preprocessing and in the meantime practice with PI

[Davey-T]

Maxim does a good job of sorting and calibrating images, everything that is done to the image is recorded in the Fits file so it can see what has been done to the image previously and so can you which is very useful if you forget exactly what you've done to it 

Dave