Switch10

I follow the same workflow with linear stretching first followed by non linear but normally ended with pixel values of around 10 which just looked unnatural. Good to hear a value of 20 (roughly) come up twice, that did look way better on my last image.

Thanks - ive always winged it to some degree so that's helpful

Hi - I'm struggling to find the sweet spot for getting a consistent background value in my images that makes it look natural and not too dark (which to me looks over processed). Also if you put my images side by side the background sky values are always different so im after a consistent RGB pixel value to target. Does anyone have a target pixel value range for the background sky rhat they aim for when tonal stretching L + RGB images and if so, what is it? Or do you do it what looks good image by image? I recently processed M81 with a background sky RGB values of around 20-30 and it looked more natural than when ive had it around 10 on other images but wonder how others tackle this? Thanks

Great image, exceptional clarity on the surface details. Nice job.

Hi, this image was taken last night and is a composite of the best 600 frames of around 2100. Processed in registax and gimp to bring out sharpness and contrast. Shot through a f5 200mm reflector using an olympus camera. Hope you enjoy!

Thanks chaps - tried PA aligning last night rotating the RA axis so 0 was as the top (just so i was sure where to position Polaris) and it tracked nicely.

That's not a bad shout. I do a similar thing with some masking tape on the dovetail to mark where I should lock in the OTA on the mount so i know it will be balanced.

Thanks Ivor - will try that way next time I'm out. I agree it seems odd as to why they wouldn't just align the clockface reticule upright in the first place. It's an extra thing to fumble about in the dark with.

Hey everyone, i know this is a question that has probably been asked a million times but i need some help with it. When my scope is in the home position with DEC axis at 0° and perpendicular to the RA axis, the clockface reticule in the polarscope is twisted clockwise 2 hours too far i.e. showing 12oclock where 2oclock would be on an upright clockface and 6 oclock where 8oclock would normally be. My question is where should i position polaris using its hour angle for my long/lat/time to get proper PA? This is causing my grief as take this example- say i use my current clockface where 12 oclock is where 2oclock should be, if polaris hour angle was 8oclock say, I'd positon it at 8oclock on the clock face. If i rotated my RA axis so that 12oclock was at the 'top' and 6oclock at the 'bottom', that same alignment of 8oclock on the twisted reticule would mean polaris would be at 10oclock on the upright clockface - a difference of 2 hours. Should i position polaris using an upright clockface (i.e. rotating my RA axis slightly so 12 is at the top) or position it on the wonky clockface where 12 is at 2? I have already calibrated my polarscope so that objects stay centre if you rotate the RA axis. Hope someone can shed some light on this, thanks.

Welcome to SGL 😁

No i didn't know those were a thing, thanks for sharing! I'd seen metal cased solar filters but those were pushing the 100 quid mark. Might consider getting one if the sun livens up and after my handmade filter undoubtedly falls apart.

Agree with the others for using the moon if you can as it's a bright, easy target. I then usually fine tune mine using a star like Vega to get it spot on. Have to do this each obseving session as i always end up knocking it when carrying it outside...

It's a 200pds but had to make the filter 6" as single a4 film didn't cover the opening and i didn't want to fork out another 20 quid for an extra sheet...

A solid looking filter that. Mine looks okay from the front but was a dogs dinner at the back! It was safe at least 😂

Same here although today I learned my craft skills are woeful 😂