Well I wasnt sure where to post this. But here goes!
During the week I was thinking if how will I be able to take a flat field shot when I am away in the field. Then it struck me - why not use a device to have a light on the inside to cover the front of the scope and take the flats that way. Well how do I do it?
I started with a 99 cent bucket (red) and I bought some osram button lights (they have 3 bright leds powered by 3 AAA batteries and are held in place by 3M tape. (see photos. I havent actually taken a shot at the moment to prove the madness but all indications are that it will work. All I need to do is ally an opaque barrier in the optical train, but what to choose? any suggestions welcome! . I also noted that on the ED80 the dust cover can be used for the same thing, the central cover is removes and with duck tape secure the light to the end.
good idea - dont know. I showed this idea to some esteemed and knowledgeable members of this site for their impressions. They suggested I wear it on my head whilest playing a theme from close encounters, to a quizzical what's it for! Personally I agree, but I think there is a practical use for this idea, for all those DSLR people out there in IIS land . i am open for input and bagging, but practical input is greatly cherished
Sorry, I don't understand what this thing is supposed to do. Lots of lights - looks like a bad thing for astronomy. Take away the "flats"? Or is this a joke I don't get?
Adds a new meaning to the term "light bucket"
I'll be interested to know but I suspect that it's going to be difficult to get the light diffused enough from what are relatively point sources.
Steve,
to explain further - when processing images after you take the dark frames and bias frames, taking flat frames helps to highlight the camera's different marks and quirks and that can be subtracted from the images you have taken in the processing of the final image. So dust motes and hairs, fly poo can all magically disappear in the final image
Adds a new meaning to the term "light bucket"
I'll be interested to know but I suspect that it's going to be difficult to get the light diffused enough from what are relatively point sources.
given the fact that you do not touch thecamrea at all nor the focus these should be out of focus and not show up as point sources, I have yet to test this theory. but I am looking at usibng a diffuser of some description.
There is method in my madness just have to prove it thats all
Why don't you place a square of diffuse plastic or similar over the end as well, that will elliminate any concentrating of the individual light sources, even the light out better.
Why don't you place a square of diffuse plastic or similar over the end as well, that will elliminate any concentrating of the individual light sources, even the light out better.
JohnG
Like of what John, plastic bag, opalescent?
Can you see this working? Do you know what I am trying to achieve?
I know exactly what you are trying to achieve, I have seen similar setups. I was thinking of something like a thin translucent plastic or somtheing like that, you have to make sure the light sourse is big enough to encompass the complete field of view of the camera and is even over that area.
I just use the sky with a white T-Shirt over the end of the tube.
Interesting Houghy...sounds way to technical for me...I do the same as John...simple white sheet over the scope and point it to the sky..preferably around 90 degrees away from the sun.
Looks like you had some fun...can't comment how it will work.
i am pretty sure the idea is to use this while taking the exposures, so no need to wait till daytime for it. I agree with john, use a white sheet houghy or pillow case or if you want to get teknickal try a piece of white acrylic, they use the white acrylic on still life photography and as a background light source for slides etc.... so why not flats.
Interesting Houghy...sounds way to technical for me...I do the same as John...simple white sheet over the scope and point it to the sky..preferably around 90 degrees away from the sun.
Looks like you had some fun...can't comment how it will work.
well my point is that when you are going to be taking several shots of different targets the orientation is not going to be the same all of the time, and maybe is something blew onto the corrector or the front lens between targets you will need new darks and flats. Does that make sense or am I just confirming i am a raving looney so you cant do that during the day!
Good luck, I can't see why it won't work so long as the area that is lit is even and full frame.
JohnG
I have seen that a while ago, thanks, but as for it being portable for field conditions I couldnt see thatwould work for me. however this one fails I will go to that scenario and work out away to make it work.
i am pretty sure the idea is to use this while taking the exposures, so no need to wait till daytime for it. I agree with john, use a white sheet houghy or pillow case or if you want to get teknickal try a piece of white acrylic, they use the white acrylic on still life photography and as a background light source for slides etc.... so why not flats.
Thats a very sensible suggestion Andrew (very different to last night Eh ) the sheet sound easy and good. i will raid the linen press, failing that and the wifes wrath, maybe the plastic
Maybe I am missing something here, but I can see one small problem if you are out in the field, what are you going to shine it on to, to get your flats? or, do you intend putting it over the end of the scope?
Maybe I am missing something here, but I can see one small problem if you are out in the field, what are you going to shine it on to, to get your flats? or, do you intend putting it over the end of the scope?
Gee, glad you told me that, would not have know otherwise. The impression I got was that you were going to shine it on the ceiling or some other flat, even surface. Would like to see a flat, looks way to bright to me if you intend using it over the tube..
Too complicated, I will stick with the white T-shirt over the tube, I know my flats are even then.
. I also noted that on the ED80 the dust cover can be used for the same thing, the central cover is removes and with duck tape secure the light to the end.
. i am open for input and bagging, but practical input is greatly cherished
just have to prove it thats all
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