Howdy
After the bad weather surprisingly clearing, got some imaging done.
A little planetary nebula near Eta carina looked like it was worth trying for, especially as Star Atlas Pro reported it to be Mag 9.29 H beta, and sure enough it was surprisingly bright. I did 2x 10 mins ISO 400 with the UHCS filter.
Next object is the Red Spider Nebula NGC 3537 in Saggitarius. Oddly its fainter (mag 13) yet has an NGC designation whereas poor old HF39 does not.
2x 10 mins also, UHCS filtered
Both shots with 10 inch F5.6 scope, hand guided. Both images here are full resolution crops from the centre of much bigger images. Minimal processing done just the standard dark subtraction etc, in Iris and Photoshop. Taken with modded 350D camera
Scott
always interesting looking at planetaries with their many different characteristics. Was the spider taken at a higher ISO, just appears to be more grain in the image.
No, both were taken at the same ISO but the Red Spider image was stretched more to bring it out, as it is considerably fainter.
No 2 planetaries are exactly the same, thats why I like imaging them
Scott
Thanks.
Now that Ive found out how to best focus, the system can be unforgiving as the slightest guide errors show. I have to be careful in selecting guide stars as being an off axis guider they arent sharp points, but elongated. If I can get one where the elongation runs north-south its much easier as I can keep it aligned on a line on the illuminated recticle.
Scott
Thanks all
Pauls excellent Star Atlas pro software is indespensible http://www.skylab.com.au/
Heres custom made charts I prepared with Star Atlas pro, the rectangle in the middle of each shot is my field of view, others represent bright emission nebulae.
Scott
Howdy. My focusser here http://www.users.on.net/~josiah/focuser/IMG_9933.jpg
has 2 large knobs with knurling machined onto them for grip. I have a bit of wire attached over 1 of them them to act as a pointer, I will take a short image, and check star sizes using camera zoom function. I will then turn the focusser knob say, in 1 row of knurling on the knob by watching it move under my wire pointer. I will take another pic. If stars larger I turn knob opposite way twice as far (2 rows of knurling, approx 2 mm) then take another pic. Usually by 3 or 4 tries I have pretty good focus.
Scott
