I've been waiting too Jay. I posted this in the M thread but it fits better here. I especially like the K series lenses. They had a short production run and were phased out as cameras and lenses downsized in the late 1970s and early 80s. As nice as the M series is, and it is nice, I find the Ks a to be more substantial. In terms of build quality they are about as good as it gets in a K mount lens.
I've had the K 300 f 4 for quite a while and it is one of my favourite lenses. Below is a recent shot with this lens. I had a tripod collar made specifically for this lens. I find it works very well on a monopod or tripod. One needs steadier hands than mine to hand hold this puppy. It can be done but you will need a bright sunny day.
I took a few shots of the tripod collar I had made for this lens. I designed it with the help of a machinist friend who made it in his shop. As many have noted this lens is hefty, especially on the front end, and needs a collar. This one works well for me and makes the SMC 300 f4 more versatile. With the collar in place it ballances perfectly on monopod or tripod. The shake reduction of the K10 is just an added bonus.
If you have this lens consider getting a commercially made product or have a tripod collar made.
I also have the smc K 24mm 2.8, 135mm f 3.5, and my all time favourite lens the 200mm f 2.5. More shots to follow from this gang soon. School is almost out! Here are a few K family portraits:
Cheers
TG