Quick questions

[Azure]

Hey all, just wondering;

How much difference visually is there between a 200 and a 250mm reflector? Are the views significantly better on the 250? (I'm looking at the Skywatcher Explorer series here)

Also, what sort of go-to mount will be able to handle OTA's of 200mm or more? Will the HEQ5 be able to hold a large reflector of that size easily, or is it worth looking at more expensive mounts? (Like the EQ6 and so on)

[John]

The views of deep sky objects will be improved in the 250 as it gathers more light and you can never have enough of that for the deep sky. On the moon and planets the difference will be less noticeable but still there under the best observing conditions.

I reckon you would need to think EQ6 for the 250. The 200 is OK on an EQ5 for visual observing but better still on an HEQ5.

[Qualia]

The 200mm - assuming you haven't got grave problems with your eyes - will give you a magnitude gain of about 7.2. The 250mm about 7.7. In other words, that's about how much more your given OTAs will add to your own seeing threshold. So, imagine you can see stars down to mag 4, the 200 will improve that to about 11.2 mag stars and the 250 to about 11.7.

This theoretical magnitude improvement of about 0.5 is a nice improvement, but I reckon a lot will depend on your own experience. For a relative novice like myself, I'm certain I wouldn't be able to notice that much difference, but for a seasoned stargazers that mag increase will be very nice.

You should also take into exit pupil when using EPs and your own atmospheric conditions such as turbulence, transparency and LP which will also play a big part in how much you'll be able to see at the eyepiece.

[Tinker1947]

If its affordable and you can move a EQ6 (preferred NEQ6) go for it, i have no trouble moving a NEQ6 and mounting the 250PDS on it, bigger is better.......

[onesmallstep]

Hi

As mentioned above the main difference will be light gathering with the 250 gulping 56% more light than the 200 which will help with resolving deep sky objects.

HTH!

[Carbon Brush]

An important (well I think so) consideration is OTA handling.

The tube size may not sound much bigger on paper. But in reality it can be a much bigger handful to take in/out of the house, put on rhe mount, etc.

I used to have 8" & 10" Orion Europa reflectors and did not think the extra light from the 10" justifed the handling issues.

Somewhere I should have a photo of the 8" and 10" dual mounted to give a size comparison. If I can turn it up I will send it on.

Of course, if you are permantently fixing the scope, things are very different.

Hope this helps. David.

[John]

On the plus side, my Orion Optics Europa 10" F/4.7 is the same weight as a Skywatcher 8" F/5

They cost a bit more though ....

[Carbon Brush]

Europa 8" F4, black.

Europa 10" F4.8, white.

[Azure]

Thanks for all the help guys!

I know it'll be a big setup, but the 250 seems more value for money than the 200, with the relative price difference not being that much. And I know it's better to invest in a more expensive mount than settle for a cheaper one that'll just about do the job.

The pictures were very helpful, gives a good size comparison! Looks like astronomy might end up becoming a form of exercise for me