Dew control for camera lenses?

Hi folks...

I got my Kendrick Digifire 7 (still awaiting the power supply stuff though) and the strip for the 11" SCT (Santa was good to me!!!!)..... happy days. However, as i will be mainly using my 350D piggybacked on the SCT for the immediate future using a variety of lenses ranging from 52mm to 82mm in aperature, and intend to use the lens hoods also for blocking stray light....... Would you recommend getting the 4 inch dew strip for these lenses?

If so, what would the positioning options be, considering that the lens hoods are rigid compare to the "wrap around" SCT one?

Any advice welcome...

Hey Steve
Just a quick message congratulating you on your recent wise purchase of the Kendrick Dew Control System, the Digifire series of controllers is second to none in my opinion and I am so glad I purchased a Digifire 10 unit last summer for my SCT. I think Mr. Michael O’ Connell has the same unit as me and Mr. Dave McDonald has the premier model and I am sure there are many other people here on the forum using Kendrick systems as well. Used in conjunction with a dew cap and its happy days, one less problem for the amateur astronomer to worry about, right!
I would like to give you technical advice on your question Steve but my knowledge would be insufficient to give you a worthwhile answer!

Clear skies
Mike

Thanks for that mike

Nice purchase Steve. I'm not sure about this though as I have never heard of anybody using a dew strip over a lens, although the dew would be kept away, one thing the may happen is that the strip will generate a thermal current inside the lens, thus distorting the image, especially on a mild night.

also, with temperature changes, your focus on infinity can shift during exposures...

Only one way to find out....

Keith..

I place the strip around the lenses as you suggect but like other say if you heat the lenses you could cause other thermal distortions.

I place the strip around the lenses as you suggect but like other say if you heat the lenses you could cause other thermal distortions.

I was thinking the same. Considering the autofocus motirs are so small and operate on very small stepper gears, you could cause disfunction through thermal expansion/contraction.

I'd go for a longer dewshield (makeshift or not) for the lens if the accompanying hood is not long enough.

Seanie.