Bought one of those. Cheap as, for 500mm. Because of the shallow depth of field, it is a job to use it handheld. I had difficulty even focussing it on a tripod as well. Still, for the price, good value and perhaps a good one to hold in your arsenal of lenses. I sold mine because I wondered just when I would use it. My photography is mainly action shots, hanheld.

Great photos. I see it was using a Kr. Now that I can see what can be done with the Kr, I have something to strive for. Thanks for sharing them with us.

I think focus issues, have become more pronounced since digital, especially for a lot of amateurs. In the days of film, you didnt take as many photos, and it took time from the end of the roll to the finished picture. It was accepted that some didnt "turn out". Nowadays, your finished product flashes before your eyes in a matter of seconds.

I had a rangefinder when I was a teenager, and dammed if I could get a sharp focus out of it. My Dad who was a professional photographer, tested it for me and said it didnt look like there were any problems, he just said squeeze dont push that button. You didnt argue with my father. But I still thought even his photos were a little soft.

Funny how disappointing results, put you off photography as a whole. Dont want to be in that situation now where less than satisfactory results, make you less than satisfied with your gear, and the art of photography.

I have been testing my Kr for bf and ff. I have found that at the upper zoom of the Pentax 55-300, 37-80, and 18-55, the AF is spot on. But at the bottom zoom level the focal point seem to be a little forward. Is an inherent problem with zoom lenses or is an issue with the KR only.

Also more difficult to focus correctly on an objects at the same distance with the lower zoom, than with the upper zoom. Is this natural, as you may have to get a lot closer with the lower zoom, to AF properly.

Probably photography 101, but it makes sense that at lower zooms, the same object loses its command of the focal point in favour of the closer surroundings, around the object. To put it another way, if you wish to use the single point AF, then you would have to get closer to effectively AF correctly on a single object.

Am I right, or is it my camera.

Tested the KR outside with some focus tests, using a row of bottles.

There are still some issues with (let me get this the right way around)the Kr focussing at a spot in front of the centre. Is that ff or bf? But only with the zooms at the lowest zoom level. But perfectly acceptable. Wouldnt like to AF fine adjust then would put the upper zoom out.

I think that you could correct if necessary for prime lenses. I cant test for that because I havent got any prime lenses.

There is a lesson here for me to learn. When taking photos dont use the zoom lenses at the bottom zoom if you can avoid it.

Any one else had these experiences or is it just my camera.

I would be interested to hear if the k5 has any issues like these, before my eventual upgrade one day.

I thought the 55-300 would be a versatile lens. But if I have focus issues at 55. The lens effectively is probably a 150-300.

My hands vary depending on what I am doing, where I am standing whether I am excited or calm, whether I have a longer lens on or not. So if I am having a good day, without rush, and a shorter lens, it probably would pay to turn off the SR. I think I will switch it off as a default and only put it on in extreme circumstances. Would prefer to rely on a faster shutter speed and higher ISO.

I have a "perfect-pixs" focus chart. So far only tried it under tungsten light. A bit useless. On the Pentax 55-300, it works really well at the 300mm. The focus is spot on with the depth of field extending on both sides about the same distance. On my Pentax 35-80, it works really well at the 80mm and again, the centre point is in focus and the depth of field extends about equally before and after.

But at the 55mm and the 35mm, the result is not good, not as well focussed and the depth of field is forward. I really couldnt get close enough to really get a good point to focus on. I think that this is the limitation of the focus chart. Unless you can get one in A1 size.

Will try again tomorrow with some bottles lined up in the sun, to see how it goes.

Yes using spot focus and very careful to focus on the light bulb. But I have a feeling that ff and bf issues which seem to arise with the Kr may have someting to do with the accuracy of the spot focus.

Will have to retest outside with a focus sheet and a tripod.

Always looking for the sharpest possible photo. Under the Custom settings No 21. Does the fine adjustment only affect the current lens, or any lens attached to the camera.

Taking pictures of a light bulb inside, with the built in flash using the 55-300 pentax lens. The bulb comes out sharp at the 300mm, but at 55mm it is not as sharp. Any ideas of what the cause would be.