|In this tutorial, we will be looking at how to take a one shot full disc image and turn it into a Chromosphere using a standard PST and Canon DSLR. The main problem when trying to image using a PST is the fact that there is not enough 'in' focus. To overcome this problem you need to use a barlow or powermate, this also has the added benefit that you get a larger image on the chip.|
|Sometimes this still does not give enough 'in' focus, so the only way to get that extra bit is to find a nose piece that has a very thin lip on it, as in the photo below.|
Or you can file/dremmel off the lip of a standard nose fitting to get the barlow/powermate to fit as flush to the t mount as you can. This then gives the extra needed to get focus.
For a full disc image I use a tele vue 2.5 x Powermate.
|As you can see from the photo, the powermate/barlow fits right up to the t-mount adapter. The 2.5x powermate give a nice crisp image and also a full disc. This setup gives a full disc and also allows you to keep the filter in place.|
|Using the zoom function, locate the rim or prom on the disc and get fine focus on this.|
Play with the exposure and ISO until you have a good image of the disc. (The sample here is on a poor seeing day with light cloud, but shows you the basics)
|After rotating and cropping the image, play with the brightness and contrast sliders in your editing software (I use Gimp as it's free and does a good job) until you get a nice even balance of colours.|