SharpCap - free Astro Webcam Capture Software

[ngwillym]

55 minutes ago, DavM said:

I have tried PA using Sharpcap a couple of times. I have a question regarding the "moving" of the RA axis. Can this be rotated by disengaging the clutch and rotating, with the mount turned off, or with the mount turned on and "slewing" with the Hand Set, or doesn't it matter which!

Thanks in advance for replies.

Dave

Neither.

If you mean moving the RA axis for alignment - as opposed to rotating the scope to take the second image -  then  to move the RA axis you have to slightly loosen the bolts that hold your mount to the pier/tripod and and then use the azimuth and altitude adjusters to move the RA axis in the needed direction(s).

Regards

Neil

[rwg]

@DavM

Either way is fine - you can use the handset/EQMOD to program a 90 degree turn in RA or just loosen the clutch and spin the axis.

Robin

[JemC]

2 hours ago, rwg said:

Either way is fine - you can use the handset/EQMOD to program a 90 degree turn in RA or just loosen the clutch and spin the axis.

Robin

tried the polar alignment procedure tonight, 1st time using something like this, so just a quick query, how many steps are there in the alignment procedure as i got to step 3 and thsi is as close as i could get, is there a step 4? as i could not see anything to say process was complete,

 

[rwg]

@JemC, no, that's it - once you have the star in the box and the green and red crosses lined up you are done. If you look at the bottom of the screen you can see that your remaining polar error is estimated to be 6 *seconds* of arc... Normally anything less than 2 minutes is considered good and anything less than one minute is excellent.

I guess the reason that there is no 'you're done' stage is that everyone has their own idea of how close is close enough.

cheers,

Robin

[JemC]

2 hours ago, rwg said:

no, that's it

superb, thanks for that Robin

and a big thank you for such a wonderful piece of software that even a numpty like me can use it,

[rodrigol]

Hi,

I'm having issues with debayering images taken with SC 2.9.x and an ASI290MC. I've posted into:

 

I'm wondering if anyone can recommend a way around this issue?

Thanks a million!

R:) 

[rwg]

Looks like you have been capturing in RAW mode, which then needs debayering to give you a colour image. PIPP is a good tool for this - on the "Input Options" page check the 'Debayer Monochrome Frames' option and then play around with the settings below to get the right pattern option.

An even better option may be to capture a video into SER format, since SharpCap puts the bayer pattern information into the SER file, so when you play it back in SER Player, Registax, AS!2 etc, the debayer should happen automatically.

cheers,

Robin

[deepview]

Hi, we chatted at the IAShow the other day.

I've download the software and hope to test it soon as this cold flu goes.

I was wondering if it would work using your telescope using a webcam and 102 sky watcher F5 telescope?

My friend has a mount where the polar scope is hard to view as the adjustment screw is to close to the polar score.

I got an other 2 ideas if you want a project or two.

[DonBoy]

Just tried v2.9.2953 with Polar Align and kept chasing settings.  Went back to v2.9.2936 and all OK.  Went back and forth afew times between 2936 and 2956 and 2956 always indicates a few minutes of error where 2936 indicates a few seconds of error.  And why does the software ask you to press the Next button again before adjusting Alt/Az 

Don

[rwg]

@deepview

I'm pretty sure that the field of view with a 102/f5 refractor and a webcam is going to be too small. There's a field of view calculator in the tools section of this site I think and you could put your focal length and sensor size in to work out what FOV you will get. For that focal length you will need a larger sensor, or to use the webcam then you will need a shorter FL.

Hope that you get cold soon and get a chance to test

@DonBoy

The way the process is designed I hadn't envisaged the adjustments being made until you'd gone to the last step by pressing next. I wasn't at all convinced that the right alignment would be achieved by adjusting during stage 2 and I'd had some reports of alignment issues from people who were doing it that way. That's why I have forced the 'press next' in the latest 2.9.

But... I just tested this morning (I have a printout of the polar sky and point a camera with a 4mm lens at it - works a treat) and actually adjusting in stage 2 does seem to work. *BUT* it only works if the plate solver continues to work on each frame as you adjust, since the target point tends to move away from the moving star a bit if you adjust in stage 2. If you adjust in stage 3 then the target point doesn't move, so you get correct alignment even if the plate solving doesn't solve every frame.

I think the upshot is that I will keep the warning to move on before adjusting as that is the most robust way of working, but I will put the arrow back in stage 2 for those who prefer to work that way.

cheers,

Robin

[DonBoy]

Robin,

What is concerning is that v.2953 initial results is 5 or 6 minutes of error as compared to v.2936when it is aligned to under 10 sec of error.  I confirmed the differences several times.  I never could get v.2953 to settle out, I was constantly chasing the changes back and forth.  

[rwg]

Don,

so I have been back and re-checked and there are only 2 changes to the polar alignment between 2936 and 2953

1) The new message telling you to press the Next button and no arrow until you do

2) Duplicate frames are ignored - that is if the camera sends identical frames twice or more in a row, SharpCap will only calculate for the first one to avoid using all CPU time on some cameras.

Change 2 should only really apply to LX modified webcams - even with integrating cameras and frame grabbers, sequential frames will be different due to noise in the A->D conversion, so that leaves 1) as the only possible cause of any change in behaviour.

I'm going to try to put out a test version later for another user who has a different bug - I will send the link to you as well and re-enable the alignment adjustment in stage 2, so you will be able to test the 2 ways in the same version to see if they really do make a difference.

cheers,

Robin

[Demonperformer]

Apologies if this has been asked and answered in the previous 54 pages - mea culpa, I haven't checked them all.

I'm starting to do some imaging with just my 1600MM & a canon lens. Is there a setting on sharpcap that will enable me to select the aperture I want to use (the lenses I have don't have an aperture ring to be able to set it on the lens itself).

Thanks.

[rwg]

@Demonperformer

Sorry, no control over the aperture of a camera lens - that requires either a manual lever being moved by the camera body or an electrical supply to the lens via the comms pins and correctly coded signals (depending on lens design). The hardware of the ASI1600->Canon converter doesn't support either of these (the electrical contacts are just dummy).

cheers,

Robin

[Demonperformer]

Thanks, Robin.

I realise this (supplemental) question is not really sharpcap, but in case you can advise ...

Do you happen to know what aperture will be selected by the camera/lens in this situation? (My guess would be either maximum aperture or last-used aperture, but would be good to get a more informed answer).

Thanks.

[rwg]

It will be at maximum aperture - lenses only stop down to the desired aperture during exposures, the rest of the time (while the camera is idle or off) they are at maximum aperture.

cheers,

Robin

[Demonperformer]

Thanks, Robin.

[DavM]

Quote

@DavM

Either way is fine - you can use the handset/EQMOD to program a 90 degree turn in RA or just loosen the clutch and spin the axis.

Robin

 Like this

 

Sorry for the delay, but thanks for your reply Robin

regards Dave

[PeterCPC]

Robin

I have a query about focusing if I may. I am using 2.9 and last night I was trying to focus on Neptune using an ASI224. Now when I use Backyard EOS with a Bahtinov mask I get a very sharp image so it is easy to focus. However, when I use Sharpcap with a Bahtinov mask the image I get is like the one below which was a snapshot. Am I doing something wrong? I tried using the Bahtinov assist but the "rays" were moving about very fast. Any suggestions would be welcome.

Peter

[Stub Mandrel]

Were you using the mask on Neptune rather than a star?

If you use a planet it's not a point source so the pattern will not be 'sharp'.

Neil

[rwg]

Yep, I've never had success using a Bahtinov on the planet itself - you need to use it on a nearby bright star. The other problem is that at longer focal lengths the pattern can be smaller and less distinct, so it may not be as easy to use as it is for shorter focal length deep sky work.

cheers,

Robin

[PeterCPC]

 

16 hours ago, rwg said:

Yep, I've never had success using a Bahtinov on the planet itself - you need to use it on a nearby bright star. The other problem is that at longer focal lengths the pattern can be smaller and less distinct, so it may not be as easy to use as it is for shorter focal length deep sky work.

cheers,

Robin

No sorry I didn't make myself clear - I was using the mask on Capella prior to slewing. When I swapped the ASI224 for the Canon the pattern was perfect on Capella with very clear spikes.

I get this issue with the 224 and Sharpcap even at shorter focal lengths like the ED120.

Peter

[Stub Mandrel]

Ah different camera! Try reducing the exposure. I have no problems getting a sharp pattern with my lifecam and Sharpcap at 2400fl (using a barlow).

 

[rwg]

37 minutes ago, PeterCPC said:

 

No sorry I didn't make myself clear - I was using the mask on Capella prior to slewing. When I swapped the ASI224 for the Canon the pattern was perfect on Capella with very clear spikes.

I get this issue with the 224 and Sharpcap even at shorter focal lengths like the ED120.

Peter

Peter,

definitely make sure that you are using similar exposure lengths if you want to compare like-for-like with another camera - for instance if you were using a longer exposure (say 1s) with the DLSR then with the short exposure on the ASI290 you will be seeing a much dimmer version of the pattern and picking up on all the fluctuations in seeing that the longer exposure is hiding from you.

cheers,

Robin

[PeterCPC]

I thought that I was using a similar exposure length (can't find the data now) and I was using Sharpcap in LX mode - it just seems that I can never get sharp spikes when I use the ASI224 and Sharpcap. I will try again soon when I next get another opportunity. Thanks Robin.

Peter