Advice on scaling sketches

[jdg600]

Can anyone offer any advice on how to correctly scale sketches relative to the field of view. I observed a few double stars last weekend but when I compare the separation of the stars in my sketches relative to the fov with the published separations I find my sketches are typically out by a factor of 2 or more

I'd be most grateful if anyone could offer any tips on how to get thing more in proportion.

[Moonshane]

I don't do anything as scientific as you. I just sketch what I feel I can see and then see if it roughly matches what I read in my doubles catalogue and other online images/sketches.

here's a few examples of mine. my method is white paper and black pens (different sizes from 0.1mm to 0.8mm tips) and I then invert in paint (very simple processing) and add coloured blobs of a size and shade as close as I can recall. putting stars around the field helps with scale I find as does using a narrower field like a plossl.

[jdg600]

Thanks for the reply Moonshane, those are lovely sketches you've done there. I, like you, just sketch what I think I see in the eyepiece but it just occurred to me when I looked at my rough sketch of Mintaka from Saturday that, in relation to the circle I'd drawn to represent the 15 arc-minute fov of my 6mm plossl the spacing of the stars is far too wide.

I guess I'll just have to work harder on trying to get things proportioned better.

[Moonshane]

I think sometimes you concentrate on the object to the point where you exaggerate the size. We all do it of course!

[Siriusmeg]

I try to sketch in the surrounding stars first so that I can then use these to plot my main subject accurately.  Finding patterns of lines/triangles helps me to get things approximately in the right places.

[Siriusmeg]

Though sometimes that brings its own problems - as when I tried to sketch Comet Jacques recently.  By the time I'd plotted in the background stars, it had shifted massively!  I drew its original position too, and added a third later in the evening.

[todd8137]

Give it what ever scale you want as long as it sort of accurate I usually centre the target on the page and then draw the dots of the stars in the fov ,if it's the moon or planets the scale again is what you see unless you wish to fill the page I did Kepler this year and started with the centre then it just took over the whole page in the end the second one as you can see I panned around the main focus as I wanted more of the group ,draw for your self and your own archive and not for others and each as there own style find yours and stick to it and always remember that the things your sketching are for you

Pat