Sub length and ISO settings for moon, and also star trails?

[ianpwilliams]

I'm hoping to get a photo of the moon tonight, weather permitting. It's only going to be my 1100D on my unpowered HEQ5 mount. So could anyone recommend sub lengths (I'm guessing not very long!), and an ISO setting? I believe it's roughly a half moon at the moment.

Also, as I'm still unpowered for now, I may have a bash at star trails at some point. Would there be a recommended sub length for decent trails, and a recommended ISO?

[Knight of Clear Skies]

It will depend on the speed of your optics, but it's daytime on the Moon so think daylight settings. Low ISO and a short exposure.

[jgs001]

For the moon, it's pretty bright... ISO 100, and probably somewhere around 1/50s (depending on your scope). Use that as a start point, check your histogram on your camera and adjust as needed. Don't worry about the shutter speed being considered lower than would be sensible, even at 1200mm, 1/10s is plenty fast enough to avoid the moon blurring due to motion, as long as the scope is firmly mounted.

[Alien 13]

As above, the key to getting good luna images is to slightly under expose and make sure you use live view x10 to get the focus spot on.

Alan

[glowingturnip]

startrails I used 30s subs at ISO1600 for this one - http://stargazerslounge.com/topic/225679-startrail-pic/#entry2429707.  Lots of them, and I think something like a 5s or 10s gap between them

[ianpwilliams]

Ok thanks for the moon tips.

Regarding the star trails, I thought we would be talking about 10min subs or something, so the stars had a chance to form trails. So how come you would have 30s subs?

[glowingturnip]

take lots and lots of them with only small gaps between, then you can combine them with a program like Starstax or Startrails.  It applies a lighten merge, which makes a trail out of the stars as they move.

If you hold the shutter open for 10 minutes or so, you will get trails too, but it's likely to get lost in sky fog or light pollution and will be far less appealing.

[jgs001]

For startrails, I use 30s, ISO 800, St the camera to continuous shooting, and with a wired shutter release mock it to trigger the shutter immediately. Keep going until you run out of space on the card, your battery runs out, clouds stop play, or you've had enough

Sent from my GT-I9300 using Tapatalk

[ianpwilliams]

Thanks, will give that a try too at some point.

[ianpwilliams]

Got a shot of the moon in the end. Obviously quite small with it just being the camera on the mount, but still detail than the blurry handheld shot from a file ago. The pain is guessing whether it's in focus, and only finding out afterwards if review mode!

[Atreta]

You could try using the zoom feature in live view to help you with the focusing with moon.

it'll be a lot easier to focus that way.

[happy-kat]

With the moon being so bright just now try a cheat.

Camera dial to landscape mode now focus on moon now move the lens switch to manual focus now turn the camera dial to m mode and set you iso, aperature etc.

Worth a try that might get what you want, even using auto focus more then once locked switch over to manual focus on lens. Use the lens switch and modes to work for you.

[happy-kat]

Once auto focus is locked and then you use switch on the lens the lens focus is set don't touch it

[ianpwilliams]

Thanks I'll note those tips for next time.

I'm on the verge of buying the 200P Skyliner Dob with a 2x Barlow to do some visual, and then buying the ED80 Pro Outfit for imaging on my HEQ5 later on.

My question is, would it be possible to take images of the moon using the Dob (assuming I bought a camera adapter)? I know that generally speaking you need a tracking mount for imaging, but with the moon only needing such a short sub, would it be possible?

[Knight of Clear Skies]

Yes, certainly possible. Boosting the ISO and shortening the exposure may help with avoiding any blurring from movement. If you want to take multiple frames probably the best way is to let the Moon drift across the field of view. PIPP can be used to pre-align the frames, which makes stacking with Registax go more smoothly.

[ianpwilliams]

Great, in that case it looks like I'll be buying the 200P Dob with a 2x Barlow, and a camera adaptor.

[ianpwilliams]

I'm guessing that an image of the moon through a 200P would only cover part of the surface, so I wonder if it would be possible to photograph different areas and manually try to create a mosaic? I'm guessing it would be tricky without tracking etc, but I would have thought that the final image could be very impressive if it was achievable.

[Tinker1947]

There are Moon Mosaic's there posted just need to search a bit, there are also DSO's i remember a M31 that got rave reviews, just need to search for them...there here some place.....

[Knight of Clear Skies]

I'm guessing that an image of the moon through a 200P would only cover part of the surface, so I wonder if it would be possible to photograph different areas and manually try to create a mosaic?

It would probably fit in if you use your 1100D, the chip is big compared to a webcam giving a larger field of view. If not I've had some success using Microsoft ICE (free software) to stitch together mosaics.

[happy-kat]

Did you try again with what you have to image the Moon?

Blur should not be an issue once focus is right as the Moon is so bright I used ISO 100 and something like 1/250 shutter speed. So on a tripod that is no blur so any blur is focus or knocked the tripod or did not use a remote shutter release though could use the 10 second timer delay. The timer can be set to take 10 images as well from one shutter press.

[Tinker1947]

A £5 webcam with the LED's squashed 1 minute exposures with Sharpcap, then put the file through Registax the result no so bad for a Fiver scope was a 250 P-DS......

[ianpwilliams]

Haven't tried since, mainly because it's so small anyway with just the camera. Quite keen in getting the dob for viewing and moon shots, just got to book a day off work for delivery.

[ianpwilliams]

Very impressive! Don't have a laptop yet though so webcam isn't an option, will have to be the camera instead

[ianpwilliams]

Ok, assuming I can get Friday off work I'm definitely going to buy the 200P Dob, 2x Barlow and t-ring adaptor (for future moon images). I've also ordered "Turn Left at Orion". Is there anything else I should be buying? Maybe a collimation tool? In which case, which one(s)?

[happy-kat]

I just use the £4.95 collimation cap with my dob.