Startralin'

[Pegasus2]

So I saw some other members photos and decided to have a go at this myself. So I post these photos for your viewing pleasure All of these are shot at my university campus.

1st Attempt



2nd Attempt



3rd Attempt




Unfortunatly on the 3rd try I encountered the abominable lens mist monster and had to throw away well over half my shots. I heard of the idea of glueing square resisters in series to a rubber band to heat the lens. Going to make one of them next.

A bit of a question: If I go out when the dew point is lower than the ambent temperature will this prevent the lens from fogging?

Presumably the lens will acclimatise to the ambient and prevent dew from forming on it since the air isnt so saturated. I suspect it will but i'm not exactly sure how the dew point usually changes overnight, does the ambient temperature fall to meet it most nights?

I've been seeing humidity levels of about 85% a lot and it was 87% the night when the lens fogged over. I think a higher relative humidity, or more saturated air, leads to a higher dew point.

 

[VirtualAdept]

I'm always impressed by star trails, and yours are no exception. I have one tiny complaint, that the buildings at the bottom of shot 3 are just a little too bright for my liking. Other than that, fantastic photos.

 

[MWHCVT]

Sorry not really able to help of the fogging issue, there are a number of schools of thought on that issues, I've heard let your kit aclimatise, use hand warmers around the lens, or set up a little battery power fan to keep air moving over the lens to stop the fogging issue, to only advise I can give is stay down wind of your camera has I've found your body warmth can fog up your kit and avoid really humid areas such as near water

I'd like to see the foreground better exposed on the last one :shrug:

What were your individual expousure values for these ones?

Matt
MWHCVT

 

[Pegasus2]

Ordered a A2 canvas print of the one above.

Cheers for the advice. Unfortunatly letting your kit aclimatise is not the way forward. The air temp will meet the dew point and when the lens aclimatises to the air temp dew will form on it. It needs to be heated.

30" f/4 or 4.5 ISO 200/400 Usually. The forground was properly exposed to begin with on that one but the fogging started at the bottom and diffracted the light.

 

[mark4183]

the picture above is amazing.... im always amazed by these pictures also

 

[MWHCVT]

Cheers for the advice. Unfortunatly letting your kit aclimatise is not the way forward. The air temp will meet the dew point and when the lens aclimatises to the air temp dew will form on it. It needs to be heated.

30" f/4 or 4.5 ISO 200/400 Usually. The forground was properly exposed to begin with on that one but the fogging started at the bottom and diffracted the light.

With the best will in the world I've done a fair few star trails and acclimatisation is generally the way forward, I've done this a number of times including several occasions where conditions were well into the minus figures and not had an issue

Matt