Grimbles

I put a 3rd screw in mine, it worked well

I use a 150pds with a 500D and the Baader MPCC. If you want round stars anywhere away from the centre an MPCC is the way to go. The stock focuser on these scopes does suffer from a little sag with a DSLR hanging off it, so even with the MPCC there will still be a little tweaking to get good stars accross the image, also collimation has to be spot on.

I use a Baader CC on my 150pds, it makes a huge difference.

HSO for me. Great natural looking image

Hi Everyone I am posting this out of frustration in that like many on here I am trying to get this season started but have only had about 5 hours of clear sky in the last two months, and that was during an almost full moon on 7th Nov hence the Ha. Nothing like enough Ha data on this yet and will, if the weather gods allow, add RGB. 19 x 600s lights , 22 Flats, 22 Bias, Dithered in BYEOS / PHD so no Darks Modded 500D, 150PDS, Optolong 2" 7nm Ha Image is cropped as framing was a bit rushed (over excited by the clear sky). This is the Red Channel only. Thanks Martin

Another +1 for Juan

Plus 1 for the 450d or the 500d. I use a modded 500d now but originally the 450d, both very good and pretty cheap to pick up secondhand.

Hi I currently use a modded 500d with my 150pds example (not the best) below. I have also used a modded 450d. In terms of noise the best ISO for the 500D seems to be 1600 but for the 450D it was 800.

Hi Everyone, Been a little while since I posted an image, mostly due to poor weather etc. Managed to get out for a couple of hours on Saturday and had a little while on M51. 150PDS with modded EOS500D on HEQ5 Guided. Only 20 x 180s Lights ISO 1600 dithered with flats and bias. Processed DSS and PS CC I still have an issue on the left side of the image with elongated stars, I have pretty much tracked this down to just a fraction of sag in the focuser which I need to try to resolve. A slight crop and and close cropped version. Thanks Martin

I had the same problem with my 150pds and like you traced it to light leak around the primary. My solution was to use a bungy loop to hold a piece of black polythene over the back of the scope, this can easily be taken on/off for collimation and star tests etc. Martin

Hi Michael, I am afraid I can't help you with the measurements as the last camera I modded was a 450D which was relatively straight forward. However I have just had a 500d modded for a very reasonable price by Juan at https://cheapastrophotography.vpweb.co.uk/ I used Juan because I wasn't confident with retaining the autofocus / keeping the sensor square and he has a lot of experience along with very good reviews on here. I have had the camera back a few days now but not had the chance to test it on a scope yet due to weather, but with a normal lens it focuses great in auto and manual. I know this does not answer your question, but just a thought if you do have any reservations about going ahead yourself. Martin