Very Long Focal Length Solar and Lunar

DSLR-Tripod Photography

 
 

I recently gave in to the temptation to buy a (very cheap) Tamron SP 01F teleconverter on QXL, so now I have two of the kind, primarily for my trusty old Tamron SP 350 mm f/5.6 Model 06B catadioptric mirror telephoto lens. This acquisition was specifically with lunar photogrraphy in mind, but as I had to wait for decent lunar weather,  I had to make do with the evening sun as it sank down through the evening clouds for my initial tests.

All images are un-cropped, ISO 100, 1/1000 sec, 1400 mm focal lenght, f/23:









Images are unprocessed JPG straight out of the box (apart from reduction in size).

YOU MUST OBSERVE:
The sun is not to be trifled with. It is not only dangerous to the camera but also for the eyes (and they cannot be replaced, as we should be aware). Images like the above can ONLY be made without special filters when the sunlight is SIGNIFICANTLY dimmed by mist and clouds.


 

Well, well - after having waited for days and finally settled for some solar photos for a test, the clouds actually spread a little around midnight on the very same day. Just a little, and not exactly clear skies, but OK for my very first 1400mm lunar test shots. Here is just a single example from my first test series:


 

Again we have a full, un-cropped picture taken with my Pentax K200D at 1/15 sec, ISO 400, 1400 mm, f/23. Post-processed using curves adding a little extra sharpness in PhotoImpact. As a first test image I should call it a fairly promising start ....

And yes, it IS 1/15 sec. at 1400 mm focal length with the camera on an ordinary, ficed tripod. The stubborn myth just doesn't hold true that the Moon should exhibit motion blur at these slow shutter speeds.

Next to show is a more thoroughly elaborated picture form a series of images taken a few days later:

8 images at 1/6 sec and 10 at 1/15 sec stacked in Registax. The colour contrast has been adjusted using a Camera Curve Profile in PhotoImpact. Using such long exposure times requires absolutely calm atmospheric conditions AND stacking is also a must.
 

I'm not saying that these are the the world's best moon photos; what I do say is that one can go quite far with relatively simple (and cheap) resources. The images shown above is both scaled and compressed for upload/ file size purposes, but you can get an idea of what can be achieved (and the limits to that) with the following 100% crops:

 




One may always argue whether this is "good enough", but you should notice how much detail can actually be seen at this long focal length. For DSLR CCD/CMOS sensors, the pixel size IS a limiting factor in respect of resolution when we use less than about 1200 mm focal length for lunar photograps.

 

 

 

AstroHome

 

Copyright 2010 - Steen G. Bruun