3and 4 minute exposures, no LP filter needed then?

[smr]

Hi all,

I got guiding for the first time last night so I was interested to see what my subs looked like at long exposures, bearing in mind I slewed over to M44 for these though - I think targets lower to the horizon may be different in terms of LP.

But, going on these two images alone - would there be any need for an LP filter ? I was firmly of the opinion that I wouldn't be able to image without one once I got into guiding but the histogram hasn't gone past half way on either exposure.

I bought a 2" OVL LP Filter just for that reason but it turns out I can't add it to the optical train as I thought I could and that I'd be be better off with a clip filter instead, but now I'm wondering if I need an LP filter at all - if I'm not going to guide for longer than 4 minutes.

 

[SteveNickolls]

Be guided by what you practically get. ? Last night there was a decent Moon shining so on a darker evening you would get the histogram more to the left as well.

Cheers,
Steve

[serbiadarksky]

How dark is your sky? This particular image was taken from my backyard withouth any filter..tell us more about your LP.

[smr]

This is what it looks like from my back garden. the light you can see on the left is neighbours kitchen light reflecting off their garage. In the middle the light from the back of someones house - they dont seem to have curtains or blinds lol. As you can see it's quite dark really, in terms of visible lights. It's a bortle 6 sky, in a village, around 10-15 mins drive from city centre. We have LED lighting but as you can probably see it seems quite well directed. Maybe my LP isn't as bad as I thought it was. I did just try 5 minute exposure on Rosette Nebula (I'm testing guiding as only just got going with it) and the Moon is directly above at 70 percent, but even so the histogram still got to half way and no more. So under new moon I think 5 minute exposures without a light pollution filter would be very feasible?