Startrails question - Logistics...

[thunder2]

Hi,

I have a few questions regarding star trails...

I’m planning on doing a star trail using a local church that’s lit up till 11pm at night as the foreground. I’m going to go for a dry, cloudless night when the moon’s not out, set my gear up and take a few shots with the church in focus when it’s still lit up. Then, after lights out on the church, I’ll amend the focus to infinity to start shooting the stars. I plan to leave it going for a couple of hours in order to get some length on the trails.

Questions: Having the church lit up and in focus for the first few shots, when I blend the photos together using Startrails.de, does this sound the best way to do this?

Also, it’s getting really cold now. Will my camera or lens suffer in the cold? Should I cover it up with a jacket or something? Does the lens mist up or anything like that?

When I’ve done star trails before, I tend to get the bright stars in but not many of the slightly dimmer stars. Am I correct in assuming the following: as wide a shot as possible (18mm), a low ISO (100), aperture f 3.5, 30 second shot for as long as I can stay awake.  Also, I plan on shooting in Raw and Jpeg.

Is there anything else I need to be aware of?

Any advice you can give me will be much appreciated.

[Sir-Henry]

This is just about at the absolute limit of my knowledge, but I would be inclined to take the first shot or several of the church as separate entities to the star trails with a low aperture so that the stars don't show up at all. Then I'd wait until the lights are extinguished for the rest so that the church lights don't swamp the relatively feeble glow of the brightest of stars. Then I could open up the aperture somewhat and use a much larger ISO number so that fainter stars will be recorded. Somehow I don't think that depth of field would be much of a problem    After that they can be stacked and processed. I'm pretty sure that there's more than one way to accomplish what you want to do, but I see this as the simplest method which has the advantage of not requiring very expensive equipment.

[hippie]

I'm am new to astro pics myself, I found some success with my canon 650D settings useing 18mm 135mm lens :- Aperture  F11, ISO speed 200, Shutter speed set to Bulb,  This will give you a continues shoot for as long as you like for star trails?.  If you find F11 to bright then go down to F8 or  F5.6,  Play around with your settings as conditions and differant cameras vary and have slightly differant settings for each of them!,  

Have fun in your project and we look forward to seeing your results!     

Hippie.

[hippie]

Oh forgot to say set your mode dial to manual then set your camera settings  up ?. 

[thunder2]

Thank you all for the advice.  I'm just waiting on the right weather now so as soon as I've done it, I'll post a pic, if it comes out alright.  @)

[glappkaeft]

Also, it’s getting really cold now. Will my camera or lens suffer in the cold? Should I cover it up with a jacket or something? Does the lens mist up or anything like that?

Is there anything else I need to be aware of?

A few hopefully helpful tips. 

The lens fogging up or frosting is just a matter of time unless the air is very dry. Covering the camera is not a bad idea but for the lens you need heat. If you have access to mains power or a substantial 12V battery (even a short dew heater strip is usually rated for at least 1A at 12V) the best best but more expensive solution is dew heater strips and a controller. The cheaper and more portable option is to go to your nearest "Outdoor" store and buy some chemical hand warmers and attach one or two to the lens with rubber bands. Don't wait for the dew to accumulate though, it takes a long time to remove it unless you use a hair dryer or infra heat gun. 

DSLRs continuously draw power when the shutter is open. So uninterrupted shooting drains the battery much faster than regular use and the cold weather just makes it worse. So an extra battery or two is probably a good idea. I drain at least two Canon 600D batteries a night. 

If you don't already have an intervallometer (programmable remote shutter) you can save yourself a lot of tedious manual shutter trigging by getting one of eBay (a Chinese copy of a name brand will cost around a tenner with postage).

[thunder2]

Hey Glappkaeft, really good idea with the hand warmers.  I like low cost diy solutions.  I've got a remote shutter so am good on that front.

Just out of interest, do you use a software app to tell you when the moon's not out, where North is and if it's cloudy, or is it just Google Weather?

[Sir-Henry]

If it's an accurate (or as accurate as possible) weather prediction then this site is about as good as it gets these days. OK, so it's a 'forecast', but they're so accurate I prefer the term prediction.

[sharkmelley]

Also, it’s getting really cold now. Will my camera or lens suffer in the cold? Should I cover it up with a jacket or something? Does the lens mist up or anything like that?

.

The camera and lens won't suffer in the cold but, yes, the lens is very likely to mist up.  Use a dewband if possible or, failing that, some kind of makeshift dew shield.

Mark

[glappkaeft]

Hey Glappkaeft, really good idea with the hand warmers.  I like low cost diy solutions.  I've got a remote shutter so am good on that front.

Just out of interest, do you use a software app to tell you when the moon's not out, where North is and if it's cloudy, or is it just Google Weather?

For the moon I usually keep track of it myself during the month, weather permitting. If I need specific times or positions I generate tables from the US Naval Observatory website or use the planetarium software Stellarium (for quick or easy stuff) or Cartes due Ciel (for more advanced stuff). I also have Stellarium on my iPhone. Heavensabove.com and especially Calsky.com are also good for more detailed and specific information on anything astronomy related (asteroids, satellites, Iridium Flares, etc.).

I'm an former boy scout and have been watching the skies since I was a kid so I usually have a good grasp of where north is. The more useful cues are Polaris at night (very accurate) and the sun during the day. If that is not good enough I use a compass, usually the one in my cell since that one automatically performs the true north correction.

As for weather forecasts I use several ones but I don't think any of them except Sat24.com (a good weather satellite site) covers the UK. My routine is to check several different sites (the Norwegian and Swedish Meteorological offices (Yr and SMHI), the Swedish public TV website (SVT) and the very detailed Polish Meteo.pl) and then evaluate them before heading out using the satellite images and my own experience. Still sometimes I'm barely more confident on this evaluation than I would have been by simply waving a dead chicken around.