Mount Tracking with a DSLR

[Mr TamiyaCowboy]

i have yet to use my canon 350d mounted to my 114mm skywatcher scope. and yet to puchase a tracking motor.

i have been playing with scope over the last few days, trying to track High altitude jetliners through a 25mm eyepiece. took me a while but i am becoming a dab hand at tracking.

i have been taking static short exposures of M42 in orion with my canon 90-300mm at its lowest focal range (90mm). is it possible to track the same nebula, using a 25mm eyepiece and the slow mo controls on the telescope to up my exposure time.

without scope i have a max window of 5 seconds before i am seeing rugby ball shape stars/trailing, and this just is not long enough to capture the dust cloud in M42. i want to hold out on a motor and try get some discount when i get my 200p.

so is it possible to do long exposures, and track using the slow mo controls. if so how fast would i need to rotate the RA slow mo by hand to track an object , but not effect the picture with streaking/trailing ?

[Tinker1947]

I think your going to have to run some tests, there could be data on the mount how much it moves per rotation ect, but nothing like a hands on..

[brantuk]

You've chosen a difficult way to do it but manual tracking photos have been done before. If it were me I'd mount the camera at prime focus using an off axis guider and an illuminated reticle with dual cross hairs to track for best chances.

You'll still be very limited to short exposure times though, and there will inevitably be star trails (rugby ball shaped stars). Interesting project but personally I'd hang out for the 200P on an eq mount

[Mr TamiyaCowboy]

You've chosen a difficult way to do it but manual tracking photos have been done before. If it were me I'd mount the camera at prime focus using an off axis guider and an illuminated reticle with dual cross hairs to track for best chances.

You'll still be very limited to short exposure times though, and there will inevitably be star trails (rugby ball shaped stars). Interesting project but personally I'd hang out for the 200P on an eq mount

going 200p in dobson format. in an eq3-2 is is way above my price range. and i do not thing anyone would mount a 200p skyliner on a EQ1 mount. i worry with the 114 skyhawk on the eq1 let alone my canon and a 90-300mm lens.

think i will spend a few more days tracking jetliners, they are really fast, and soon go beyond my speed of tracking, but for about 5+ seconds i can keep one framed nearly dead centre.

glad it has been done shall do a few test runs on jets, then try orions belt triple / maybe jupiter something thats fairly easy to start with. i think getting the mount close to perfect polar alignment is key to.

[themos]

If you have a laptop, then get a webcam attached to the 114 and then you'll have a more relaxed position for controlling the slo-mo knobs as you watch the webcam output on the laptop. It will require a steady hand, I'm afraid, but it could be done.

[themos]

i think getting the mount close to perfect polar alignment is key to.

You might be interested in this then

http://stargazerslounge.com/diy-astronomer/108643-help-me-test-my-polar-alignment-procedure.html

[Mr TamiyaCowboy]

If you have a laptop, then get a webcam attached to the 114 and then you'll have a more relaxed position for controlling the slo-mo knobs as you watch the webcam output on the laptop. It will require a steady hand, I'm afraid, but it could be done.

thought about webcam, but i may have to get a new one. the MS 5000hd has some bad dust on the Cmos, tried a cotton bud and rocket blower to no avail, still bad dust and very ugly. and the brightness mixed with the gain control is ugly to and a pain to get just right.

i think hands on will be my style with a 25mm eyepiece or maybe a 10mm, and use the dslr screw mount on the sw mount rings. it means removing finderscope as this blocks the 90-300mm lens but no bother to me.