I've had a brain wave regarding my imaging setup?

[Chris]

I'v got really into AP over the last 6 months or so and I'm currently using a ZS 66mm Apo on a mk1 HEQ5 mount with my Modded Canon 350D. Wanting to progress I found a bit of extra money to try and upgrade my kit and after much thought settled on trying to improve my little wide field apo with a field flattener reducer and placed an order for one. Unfortunately my orders gone a bit pear shaped and my money is in the process of being refunded, so I've been thinking if there is any better use for this money?

I had a bit of a brain wave after Olly Penrice commented on one of my images of M51, he said something along the lines of you did well considering your scope isn't best suited to galaxies, and he informed me that a longer focal length is better for imaging such objects but not to even consider it before I've got myself guiding because of the increased demand on tracking. I hadn't considered that different focal lengths favoured different objects before i.e short for widefield like m31 or the rosette neb, or long focal length for objects like M51 or planetary nebs etc.

So I got to thinking I've got myself a nice little widefield scope, maybe I should spend the money returned to me on a second OTA which would be better suited to smaller apparent sized DSO's?

The first type of scope that springs to mind is a reflector becasue the focal length is quite long e.g. a 1000mm for a 200p yet they are still very fast f/5. I had a brief play with the old blue tube 200p that came with my HEQ5 and I sold it pretty quickly after realising that personally it was to big for me to handle beings am quite light boned:) so I am now considering something like a 150p/pds which still has a focal length of 750mm @ f/5 which is double the focal length of my Apo so it should be suitably different to my existing scope?

The brain wave I've had is that I could possibly piggy-back my 66mm Apo on a 150p on my HEQ5 mount and use the 66APo for widefield and the 150p for tighter objects with the 66apo as a guide scope to compensate for the longer focal length. all I would need to do is the shoestring ST4 mod previously performed by QM and Stan26 amongst others and I'm away for not much money, just the price of a second hand 150p and a good webcam and ST4 mod.

So basically I'd like advice on whether the 150p would be different enough to my Apo to warrant doing this?, and are there any budget OTA's that I'm not considering which people think would be better for this purpose? or can anyone see any potential holes in my plan?

Any advice or opinions will be very much appreciated,

Starfox:icon_salut:

[johnrt]

Why don't you pop your camera and scope details in here Field of view Calculator<script src="title2.js"></script> it will give you a good idea about the fov you will get with different scopes.

Bearing in mind though if you move to something like a 150p you will also need a coma corrector.

[Chris]

Thanks John thats a great idea, I've had a play and a 150p will give roughly half the field of view and twice the resolution compared to my 66Apo, so it looks promising:)