alacant

For such a cheap telescope, we thought the detail was good. Stars rubbish! @Mr Thingy are your stars worse? Could you post an example? We don't know what to expect from the 72ed. Cheers

Hi Here's our version, also with a 72ed. But yeah, the halos around bright stars are awful compared to that obtained with our reflectors. Cheers

Hi Excellent shot. Loadsa detail. StartTools 1.7. Gave me the chance to get the secondary point spread thingy right:)

+1 An astro camera with a sensor anywhere near the size of the aps-c of your 1300 is going to cost €silly. Modern software and processing techniques produce excellent images with data from a DSLR. Cheers

Hi Yeah. I'm sure you'll like it. Here's the owl with the f5 version of your gso. For added detail, stick a UHC filter on the end of the cc but also note that if you do, you'll lose most of the galaxy:( If it's not holding collimation, try compressing the springs a little more by turning the adjusters clockwise a turn or so.

Ah, the owl. Lovely shot.

Yeah, we use the GPU cc too. It's very good, but the small amount of false colour we do get had its source in the cc. Easily eliminated however and certainly no fattening of stars. Try with and without. You may get away with no cc.

Refractor lenses not focusing all wavelengths at the same point.

Hi No. No fat refractor stars:) Everything is focused at the same distance. The only refractive stuff is the coma corrector and filter. I think modern sensors cut off reasonably sharply either side of the visible. Cheers

Hi everyone Found another half decent lens. This time a €60 Takumar 200mm. 1970s I think. A few irregularities but I'm almost certain they're due to the filter. I'm thinking of a AP with old lenses sort of thread. I think it's a good way to start in AP. If there's enough interest, we could compile evidence as to their usefulness etc. LMK what you think about the old lens thread and thanks for looking. Do post yours too. Takumar 200mm on eos700d @ ISO800. 3 hours. UHC

Hi We also use the GPU cc on a 208mm f3.9 with and without front threaded filter. No rings, but a few thoughts... My bet would be on the filter causing the rings. You should have enough space in your allocated 55mm to put the filter at the camera side. Easily tested by taking a flat frame without the filter. IIRC, the light panel reduces its brightness by varying the refresh rate. Anything less that 1s exposure on our panel and we get bands appearing on the flat frames. Maybe try that too? A sheet of white card works well. One last thought. as @vlaiv surmises, with the 533, you may get lucky and not need the cc. Cheers

Yes. If you are sure that the 5d sensor is orthogonal, loosen the m48 collar inside the adapter then with the telescope vertical and with light pressure pushing down on the rear of the camera, tighten the grub screws gradually. If not, get a m48 tilt adjuster. I think there's a dedicated one for the cat. HTH

Try EKOS' latest SEP multistar with GPG for RA. A pleasant surprise if ever there was one in AP:) Oh, and yeah. definitely a dither after each frame. Somewhere around 8 px is good we find. Cheers

Lovely shot. Don't know the lens, but it looks very good. We find that for the 450d, ISO400 with a dither between frames works well. Coincidence: I've a remote session in progress with a Takumar 200mm at the moment. Almost the same framing ...

The screw nearest the telescope tube adjusts the tension of the focuser, the other locks the focuser in position. Loosen the latter fully until you have reached focus with a tension sufficient to hold your camera but at the same time being able to focus with a little resistence. HTH

? You set the coma corrector at 58mm (which you have already done) from the sensor and leave it screwed tightly into your t-adapter. Then you leave it. Focus is always by using the knobs. The coma corrector makes no difference to the method of focusing. Cheers

Hi everyone Pushing the zeiss to an aperture of a whopping -erm- 35mm. Still holding up. Here with the UHC which seems to control the stars well. Strange how the latter resembles more a mirror when viewed even slightly non-orthogonally. One of the few old lenses which seems half decent. Thanks for looking and do post your old lens shots too. 700d @ ISO800

Anecdote and link. Left by a visitor some time ago. It bears no distinguishing markings which would lead to easy identification. A nice surprise to find out what it was. Works great even with rubbish refractors e.g. a 72ed: corner to corner over aps-c @ 132mm spacing. Use the official spacings at your peril. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p10307_TS-Optics-REFRAKTOR-1-0x-Flattener-Bildfeldkorrektor---2--Anschluss.html HTH

No. It's easy. Once you've the bits and bobs, it takes around 20 minutes, if that. (I updated the post. Please check the other stuff you'll need to do).

Hi The camera is tilted quite badly left to right and therefore you may have missed focus: Send an example of each of the frames you used if you like. If not we can only be general. Otherwise, it's good. Maybe just make sure your flat frames are taken correctly and lose the filter? Cheers

Yes. You need to replace the primary mirror springs, fit a proper dovetail plate and tie the top of the rings with a stiff rail. GSO are renowned for bendy cells and tubes;) Details, here.

Looking good. Firstly, make sure that the dioptre adjuster on the camera viewfinder allows you to focus the camera using a conventional lens. Now starting from that -fully inward- position and aimed at something like a tv antenna or distant building, slowly wind out the focuser whilst looking through the camera viewfinder. Stop when you can see an image and tighten the locking screw on the focuser. Now again looking through the viewfinder, find Capella, Rigel or Sirius. Next... ... WITHOUT moving the telescope, set APT live view with an exposure at 30s and look for the star. The actual infinity focus position is slightly toward the main tube (inwards) from the position you set terrestrially. To help nail the focus, you may want to get one of these. You're nearly there now:)

It needs to be 58mm from the shoulder of the m48 thread. Baader supply an adapter m48-m42 with the corrector which will get you close. See the diagram.

This is why you can't reach focus. Remove the extension tube and place the coma corrector directly into the focuser.

Hi Your first two images are out of focus and with the telescope out of collimation. The last image shows only hot pixels. Maybe start by collimating the telescope; the secondary mirror is not centred either in the tube nor in the focuser. (It is however normal to see distortion of out of focus stars when using a coma corrector.) Afterwards, make sure that you are focused on a bright star in live view. Then you should see some stars in a 30s exposure. Stick to ISO800. Cheers and HTH