Beiträge von Peter M.

Dear All,

Can you please share if you have any opinion about these two cameras?

1. DSPro Deep Sky Pro 2600 (link: https://teleskop-austria.at/DSPro2600c#m )

2. OGMA AP26CC (link: https://www.skeyetek.space/bou…AP26CC-IMX571-p563383269/ )

Both are build to be the competitor of the ZWO ASI 2600 MC cam, with same Sony IMX571 sensor.

Im simply curious if these two are maybe still a great alternative vs ZWO, or miss something important.

The only difference i could find so far is that these cheaper versions may be not coming with Industrial grade sensors but consumer grade only (i.e. shorter shelf-life of the cam). The OGMA would add some additional filters to the cam though and the price is definitely looks super competitive.

Many thanks for your comments in advance!

Peter

Dear All,

Can you please share guidance on the most important selection criteria for autoguiding techniques for a 1500 mm focal length / 127 mm aperture MAK telescope?

I'm aware of the OAG and 'classical' technique in theory, but curious if there is maybe any rule of thumb that applies for long FL telescopes for instance.

Is there any exclusion criteria why not to go for OAG if it is cheaper and provides less load on the mount?

thank you in advance,

Peter

Dear Hartmut and Jochen,

many thanks again, you gave me new ideas and learnings. Few comments on your suggestions:

1. Which is better, using SynScan hand controller or direct PC - mount connection? -> to be honest, i am confused whether it is better to use hand controller or not. There are quite some videos out there how to polar align and star align with HC before imaging sessions (e.g.: https://www.youtube.com/watch?v=adKut0KPgHw
2. So far I used the HC only for star alignment and did not use the combo of APT + Plate solving, simply because APT was crashing when activating "live view". Now i got the latest release full version, and it seems to be OK. Regarding Plate solving, I  found this video, seems to be straight forward AND it is using the hand controller: https://www.youtube.com/watch?v=K8R0X-B6M7Y&t=29s    What is your opinion about this plate solving approach?
3. @ Jochen regarding question "Do you first connect the controller, do the alignment and then unplug it in order to connect to the laptop?". Well I used two techniques:
   1. With HC: I first did Polar alignment, then 2 star alignment, and then connected the mount via the HC to the laptop, and used Stellarium to slew. APT was used for photography only.
   2. Without HC:  I first did polar alignment, then I connected to PC directly (cable btw mount and PC), and used Stellarium and ASCOM EQ MOD to slew. I did star jumping, corrected the offset via using the "sync" option of Stellarium. APT again was used only for photography.

Although I do not use iOptron (thx for the idea, nice kit), I believe my polar alignment is good enough, as polaris remains in the target circle of the in-build polar scope when moving the RA. I totally agree that plate solving will help a lot more.

Can you please advise me if you suggest to do all the polar alignment, star alignment, plate solving WITH or WITHOUT Hand Controller (Skywatcher HEQ5 Pro mount) ?

thanks and best,

Peter

Dear All,

now it gets more interesting. I tested the mount (SkyWatcher HEQ5 Pro) with its SynScan hand control, which was then connected to PC. I did first a polar alignment using the internal polar scope, continued with a 2-star alignment with the hand controller, and subsequently executed a polar alignment using the hand controller. Last step included corrections in Elevation (Mel) and Azimuth (Maz) offsets. It went well, error was reduced to 0-2 arc secs. Then I connected to Stellarium, and slewing precision was great, found many objects by hopping.

Once I started imaging, using exposure time between 5 sec up to 30 sec, the same issue happened: the first few image seems to be fine and I see round stars. After few exposures, significant star-trailing appears, even at 5 second exposure. This is something new, did not have before, and such an EQ mount should be supporting nice 5 sec exposures.

I am afraid, I have a hardware issue.

Any comments, suggestions are much appreciated.

Kind regards, Peter

Dear Jochen, Hartmut,

would you have any suggestion for a guide scope and guide camera for the an imaging scope with 1500 mm focal length / 127 mm aperture and a main camera for:

1. Canon EOS 1100D, 22.2 x 14.8 mm sensor size, resolution: 4272 x 2848, pixel pitch = 5.18 um,

2. dedicated astrocamera, 23.48 x 15.67 mm sensor size, 6224 x 4168 resolution, pixel pitch=3.73 ?

Many thanks again,

Peter

Thanks again.

I thought the reason of the not round stars on that photo was that with slight temperature changes, i got out of focus during the session. My scope has manual focus and i did not refocus with Bathinov mask during the session after doing it at the beginning.

Best, Peter

Dear Jochen and Hartmut,

Thanks again, im very new to this forum and trully appreciate experts like you are commenting my issue already.

Some additional response to you.

1. Indeed, I am using APT to capture images but have a very old DSLR camera. The HEQ5Pro for sure not the best mount but was a recent invest for me and huge step forward vs. my old ALT-AZ GOTO mount from Levenhuk. :)
2. I will reset the ASCOM Pulse guide setting, did not know, thanks.
3. I do have a build-in polar scope in the mount.
4. Regarding guiding, i will invest into it in the future, but let me share the photo attached, which I made with the same mount/telescope/camera few month ago. Super amateur image but it is a stack of 178x individual subs from M81, 45 sec each. The trailing appeared around 60 sec exposure only. I had the same camera/mount/scope, except that I was using the SynScan hand controller and obviously the polar alignment was different then. 

Best Regards,

Peter

Dear Jochen,

sincere thanks for your response. When I was connecting the mount to the PC via the SynScan Hand Controller, I could easily go up to 70 sec of single exposures without any guiding camera. I assume the precision of my polar alignment was just the same. Even my old Alt-Az GOTO mount was better in keeping the objects in center. Probably my polar alignment is worng then.

Kind regards,

Peter

Dear All,

I kindly ask ideas, guidance regarding below issue.

My setup: SkyWatcher HEQ5 Pro EQ mount, 1500mm focal length/127mm aperture tube, no hand controller used, i.e. the mount is directly connected to PC, using stellarium and ASCOM EQ MOD for controlling the mount.

My step-by-step protocol: 1. levelling mount, 2. balancing RA and DA of the setup, 3. Polar alignment, 4. Direct connecting of mount to PC with Stellarium (via ASCOM), 5. Slewing and synchronising selected stars using Stellarium (Ver. 23.1), 6. start imaging session.

My issue: After star alignment described above, I could easily find and sync with my targeted deep-sky object. I started 60 sec exposures. The first 3-5 images are nice, object totally centered in field of view, no star trailing, round stars, etc. Then a small star trailing appears and it is worse and worse by each sub exposure. It looks like the tracking is simply getting worse and worse; or the tracking is simply not working, and the object falls outside after the 10th sub exposure. I checked, all clamps are tightened. The same issue occurs again if I redo the entire polar and star-alignment process. Please see some subs attached to show the issue better, and I attached my EQ MOD ASCOM settings too.

My questions:

1. Is it a polar / star alignment issue or rather a tracking issue?
2. Can you please tell me what should be the protocol for polar and star alignment in case the hand-controller is not used and the mount is directly connected to PC?
3. Can you please tell me what should be a good starting setup for tracking in Stellarium? 
4. In the ASCOM control panel, which tracking rate should I select? Sideral tracking maybe?
5. Is it simply more advised to keep on using the hand controller and do not connect the HEQ5 Pro mount with PC directly?

Please advise, what could go wrong!

Thanks a lot in advance,

Peter