Equipment: ♦ Bresser AR90S – 90/500 F/5.5 ♦ Skywatcher Star Adventurer Pro ♦ Zwo ASI 183MC Pro (cooled)
I attempted to grab some images of the Pleiades last evening, but have no idea what I've done wrong.
On first setup, the Bresser has nice pin-sharp images of the stars in the eyepiece. Then, after attaching the Zwo I adjusted Sharpcap settings to match those of other images found online: RGB24, Gain 120, Exposure 60s.
Nothing even faintly recognisable appeared onscreen. I then tried slight adjustments up/down for both gain and exp - all I ever get is a completely black or very pale image.
The camera is definitely working - as I tested it yesterday afternoon and images of tree branches some distance away were nice and clear.
I'm clearly missing something obvious here, but can't see what.
any help appreciated.
M45 Pleiades - Failure
Re: M45 Pleiades - Failure
Swapping the eyepiece for the camera can result in a shift of the image and potentially being off-target. I used to work that way but consider following the steps below. The example shows an Altair 183C and how a 90s exposure of M45 would look when captured as a FITS image.the Bresser has nice pin-sharp images of the stars in the eyepiece. Then, after attaching the Zwo I adjusted Sharpcap setting
The tower is about 1 mile away. The setup is carried out as the sun sets (for safety). These are my steps:
- Using the eyepiece, find the land based object and focus.
- Align the finder scope/red dot finder to point to some feature (in this example the top of the tower).
- Swap the eyepiece for the camera.
- Start SharpCap, connect the camera and turn on the reticule. At this point, the focus will be close but the object may have shifted.
- Centralise the object with the reticule and adjust the focus.
- Check/adjust the finder scope/red dot finder to align with the centre of the image.
This is an actual capture of M45.
The nebulosity of M45 will not be visible on a single frame. Some techniques to help check that the object is in the field of view:
- Turn up the gain to more than 50% to check the object.
- Use the Display Histogram Stretch to brighten the onscreen image (see the focus image above).
The above process leads to me reliably finding objects, especially with the wide field of the 183C.
Dave
Re: M45 Pleiades - Failure
thanks Dave. really helpful stuff.
will give it a go next time the skies clear.
will give it a go next time the skies clear.
Re: M45 Pleiades - Failure
Let us know how you get on. Your query is fairly common.
This was my last M45 (heavily cropped), a 66mm refractor under Bortle 6 skies.
Dave
This was my last M45 (heavily cropped), a 66mm refractor under Bortle 6 skies.
Dave
Re: M45 Pleiades - Failure
well the forecast here is overcast for the next few days. a real pity as the Mars/Pleiades conjunction occurs Weds & Thurs.
Re: M45 Pleiades - Failure
@ Brenski
Maybe stupid question but what you see, is that when you use SharpCap and make a 1 captures or a bunch of captures and then stack them?
If it is 1 capture, then you will only see (faint) stars. You can "enhance" that view by clicking the AutoStretch button on the right side (the little button with a lightning symbol at the little histogram. This will brighten the view as a kind of temporary brightness boost but on screen only.
Menno
Maybe stupid question but what you see, is that when you use SharpCap and make a 1 captures or a bunch of captures and then stack them?
If it is 1 capture, then you will only see (faint) stars. You can "enhance" that view by clicking the AutoStretch button on the right side (the little button with a lightning symbol at the little histogram. This will brighten the view as a kind of temporary brightness boost but on screen only.
Menno
Re: M45 Pleiades - Failure
@Menno thanks for the reply.
definitely nothing visible. with gain/exp slider adjusted significantly.
I've used sharpcap in the past for timelapse allsky stuff and it always worked fine - so I (kind of) know where gain/exposure-wise stars should start to appear. odd that nothing did with this.
definitely nothing visible. with gain/exp slider adjusted significantly.
I've used sharpcap in the past for timelapse allsky stuff and it always worked fine - so I (kind of) know where gain/exposure-wise stars should start to appear. odd that nothing did with this.