All Forum Comments
Comment by johnriley posted on Just another old fogey... at 11/07/2014 - 17:33
This is what I concluded for the EPZ test, which doesn't really contradict was you are saying about Photozone, but it does explain why there is this division of perception:
Quote:
At 18mm, the lens puts in its strongest performance. The MTF50 chart shows good levels of detail, albeit it falling off in the corners. The MTF20 chart reveals a contrasty lens that has a high visual sharpness. This contributes to the good overall perception of the images. In terms of chromatic aberration, the centre of the field is very well controlled but this falls off dramatically towards the edges. It is in the area of distortion that things have been really let go, and we have quite high levels of barrel distortion that would easily be noticeable in architectural shots.
By 35mm the distortion and CA are coming under better control, and the high contrast is well maintained across the frame. The fine detail as shown by the MTF50 chart is not there in the corners, but is reasonable to about half way across the field. Images still look good because the coarser details are reproduced very well.
This pattern is maintained through the 70mm and 135mm charts. High central resolution falling over very severely towards the corners, good even contrast across the frame and good central control of CA being allowed to drift considerably toward the outer field and especially the corners. Distortion is quite visible throughout as it varies from wide angle barrel to telephoto pincushion.
However, we do not routinely buy lenses to take pictures of test charts and in the real world this is a very attractive lens that produces really good images. This is clearly because high visual sharpness is achieved through an excellent MTF20 result, where coarser detail is reproduced well across the frame.
Verdict
There is a lot to like about this lens and in a practical sense it gives a good account of itself. There are design compromises that have led to drawbacks, but often it is a matter of matching a lens design with the desired application.
If a lens for architecture and copying of documents is wanted, then this is not it. If it is wanted for general shooting of pictorial subjects and portraits then the lens produces excellent, visually appealing images that have a very attractive character about them. When we add to this the ability to keep shooting in the rain and cold, then we do have an extremely versatile option for Pentax users. In terms of handling the lens is an absolute joy to use.
At 18mm, the lens puts in its strongest performance. The MTF50 chart shows good levels of detail, albeit it falling off in the corners. The MTF20 chart reveals a contrasty lens that has a high visual sharpness. This contributes to the good overall perception of the images. In terms of chromatic aberration, the centre of the field is very well controlled but this falls off dramatically towards the edges. It is in the area of distortion that things have been really let go, and we have quite high levels of barrel distortion that would easily be noticeable in architectural shots.
By 35mm the distortion and CA are coming under better control, and the high contrast is well maintained across the frame. The fine detail as shown by the MTF50 chart is not there in the corners, but is reasonable to about half way across the field. Images still look good because the coarser details are reproduced very well.
This pattern is maintained through the 70mm and 135mm charts. High central resolution falling over very severely towards the corners, good even contrast across the frame and good central control of CA being allowed to drift considerably toward the outer field and especially the corners. Distortion is quite visible throughout as it varies from wide angle barrel to telephoto pincushion.
However, we do not routinely buy lenses to take pictures of test charts and in the real world this is a very attractive lens that produces really good images. This is clearly because high visual sharpness is achieved through an excellent MTF20 result, where coarser detail is reproduced well across the frame.
Verdict
There is a lot to like about this lens and in a practical sense it gives a good account of itself. There are design compromises that have led to drawbacks, but often it is a matter of matching a lens design with the desired application.
If a lens for architecture and copying of documents is wanted, then this is not it. If it is wanted for general shooting of pictorial subjects and portraits then the lens produces excellent, visually appealing images that have a very attractive character about them. When we add to this the ability to keep shooting in the rain and cold, then we do have an extremely versatile option for Pentax users. In terms of handling the lens is an absolute joy to use.
Comment by johnriley posted on 18-135mm or 18-55mm ? at 11/07/2014 - 13:15
It sounds like a misunderstanding about warranty rather than regular servicing.
If you download the special form from the menus above, I think it's under the Shop tab, and send it with the equipment you should get the discount.
That's how it worked when I had my K10D repaired.
If you download the special form from the menus above, I think it's under the Shop tab, and send it with the equipment you should get the discount.
That's how it worked when I had my K10D repaired.
Comment by johnriley posted on PU+ and JPSS discount at 11/07/2014 - 12:36
Please remember PU is for Pentax images only. I won't remove it but for the future, please bear it in mind. many thanks.
Comment by johnriley posted on latest stuff from walks and danders at 11/07/2014 - 09:26
The second one for me, very nice black and white tones and a hint of potential menace.
Comment by johnriley posted on latest stuff from walks and danders at 11/07/2014 - 08:05
Please don't get into a "bumping competition"...that's likely to irritate your buyers rather than help. Thanks.
Comment by johnriley posted on FS. Pentax DA 12-24 & 17-70 SDM lenses at 10/07/2014 - 08:43
Please don't bump these en masse or daily, your potential buyers might even be put off by that. Thanks.
Comment by johnriley posted on FS - Pentax-F 50mm f1,7 (1156009) at 10/07/2014 - 08:41
It was a captive bird, at the Rutland Owl and Falconry Centre. The beauty of this place is that many of the birds are out in the open in natural woodland. They are tethered, but with care this can be made less obvious.
It was in quite a dark situation so I kept the image dark. What sort of owl it is I'm afraid I don't know.
It was in quite a dark situation so I kept the image dark. What sort of owl it is I'm afraid I don't know.
Comment by johnriley posted on My Favourite Owl at 09/07/2014 - 17:46
The tecnology in the K10D is a few years old now, so not the best for sports action using AF.
The alternative is pre-focsing on an area and waiting for the action to arrive there. This works well for some wildlife and motor sports, etc.
The alternative is pre-focsing on an area and waiting for the action to arrive there. This works well for some wildlife and motor sports, etc.
Comment by johnriley posted on New toy for me at 09/07/2014 - 11:27
You could pay more for a K-5 or K-3, but unless you need the extra features, you don't have to in order to make great images.