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Comment by dcweather posted on Macro lenses: Sigma 105 vs Pentax 100? at 09/11/2011 - 18:56
Cheers Timothy.
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 08/11/2011 - 13:01
OK, thanks for the useful comments. It's helped me go through a logical thought process. Part of it is, I guess, the new SRS deal is so good compared to previous prices that the net difference after selling a fairly new K-r would only be about £250. I guess that differential will remain similar from now on so maybe a nice macro lens will remain next on the list - till next year! Now about that Skoda I'm thinking of getting .....
Dave
Dave
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 08/11/2011 - 10:50
I think you are right John. I seem to like these sort of questions! It's the continuous quest of new model after new model, be it cars or whatever that we seem to have these days. I'm just trying to be open minded and put maybe a slightly different angle on it. Only the individual can really answer it and as you say, does depend on the individual's needs.
Really challenging conditions aren't as common as they used to be.
I just wonder if I went in the garden with a K-r and K-5, put them on a tripod and took similar shots of birds on a feeder in reasonable light at say ISO 400, f8 with my DAL 55-300,cropped them say 50% and viewed them full screen on a 19" monitor, or printed them A4, if I or anyone would see any real difference in any particular aspect.
To me, apart from weight, the other advantages of the K-5 are clear cut.
Thanks for the interesting comments,
Dave
Really challenging conditions aren't as common as they used to be.
I just wonder if I went in the garden with a K-r and K-5, put them on a tripod and took similar shots of birds on a feeder in reasonable light at say ISO 400, f8 with my DAL 55-300,cropped them say 50% and viewed them full screen on a 19" monitor, or printed them A4, if I or anyone would see any real difference in any particular aspect.
To me, apart from weight, the other advantages of the K-5 are clear cut.
Thanks for the interesting comments,
Dave
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 07/11/2011 - 22:35
davex wrote:
Davex.
----------------Quote:
but a pro camera shot generally looks better
Probably because a pro is usually a better photographer, have never used a KR so cannot comment on that, but as is often repeated here the K5 is just fantastic, just go and buy one, you will not regret it.but a pro camera shot generally looks better
Davex.
Sorry Dave - like I said, worded badly , I don't mean taken by a pro, I mean taken with a "pro" rated camera.
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 07/11/2011 - 22:05
Badly phrased - you know what I mean mdc!! I'm not talking photography skill, artistic quality, here, I'm fully aware that some of the best shots I've ever seen haven't come from expensive cameras. The point I'm clearly failing to make is that if you line up a K-r and a K-5 side by side on a tripod and take the same pic, what are the salient differing technical improvements that will give the K-5 a higher quality image, if at all? i.e improved sensor, software or what because it ain't the weather sealing that's for sure. Interesting that as Bill says above, people are tempted to upgrade because of the listed improvements in spec,without thinking what will really change. I think he hit the nail on the head regarding at what point you decide to upgrade a lens as opposed to the camera.
Dave
Dave
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 07/11/2011 - 19:28
Thanks, but I'm not quite getting my point across very well! I'm fairly knowledgeable with regard to the specific differences, but a pro camera shot generally looks better. Now in this case is it the extra resolution, the sensor is better, the software is better or what? It's not because it's weather sealed, focuses faster or shoots at a higher frame rate etc! I wouldn't upgrade yet from my K-r unless there was something definitive improving the IQ.
Dave
Dave
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 07/11/2011 - 17:15
Clearly the K-5 has a number of more advanced features than the K-r. Many of these relate to things such as ease of use, faster performance, weather sealing etc. But what are the main factors (differences from K-r) that will make me look at an image and think - wow! that looks much better than my K-r image taken in the same circumstances?
Dave
Dave
Comment by dcweather posted on Image quality of a K-5 vs a K-r at 06/11/2011 - 23:42
When I look at the form there are boxes to tick for with lens and body only. Both are showing £90 cashback,
Dave
Dave
Comment by dcweather posted on Pentax K5 & Q Cashback! at 06/11/2011 - 21:15
ChrisA wrote:
The thing is, if you use a longer focal length lens (or a teleconverter, which amounts to the same thing), you get extra magnification at the same distance from the subject.
If you use extension tubes, the only reason you get extra magnification is because you move the camera closer to the subject. Focusing is the moving of the lens along its axis towards or away from where you want the image to be in focus. Extension tubes do nothing except help you move the lens further away.
It's the same with macro lenses - they're macro lenses because they allow close focusing, not because they have a different focal length than a non-macro lens.
You dial in more SR with longer focal length lenses because they magnify more than shorter focal length lenses. So for a given angular displacement of the camera (read shake), the image on the sensor moves more than with the shorter lens, and hence needs more correction.
The lens with an extension tube is not magnifying more in the same sense. The image is bigger only because you're closer - there's no extra magnification. So for a given angular displacement, the amount the image moves is the same, so needs the same correction.
---------------dcweather wrote:
But surely the SR requires a focal length input only to calculate the approx magnification and hence the shake? This would be more with extension tubes, teleconverters etc so why isn't more SR needed in the algorithm calculation when they are added?
For teleconverters, yes, more SR is needed, since they make the lens magnify more. For extension tubes, no, more is not needed, since they don't.But surely the SR requires a focal length input only to calculate the approx magnification and hence the shake? This would be more with extension tubes, teleconverters etc so why isn't more SR needed in the algorithm calculation when they are added?
The thing is, if you use a longer focal length lens (or a teleconverter, which amounts to the same thing), you get extra magnification at the same distance from the subject.
If you use extension tubes, the only reason you get extra magnification is because you move the camera closer to the subject. Focusing is the moving of the lens along its axis towards or away from where you want the image to be in focus. Extension tubes do nothing except help you move the lens further away.
It's the same with macro lenses - they're macro lenses because they allow close focusing, not because they have a different focal length than a non-macro lens.
You dial in more SR with longer focal length lenses because they magnify more than shorter focal length lenses. So for a given angular displacement of the camera (read shake), the image on the sensor moves more than with the shorter lens, and hence needs more correction.
The lens with an extension tube is not magnifying more in the same sense. The image is bigger only because you're closer - there's no extra magnification. So for a given angular displacement, the amount the image moves is the same, so needs the same correction.
Yes, that seems to make very good sense.
Dave
Comment by dcweather posted on Shake reduction and focal length at 04/10/2011 - 13:42
Makes my purchase of the Sigma 105 a while ago seem an absolute steal. Jessops in Norwich closing down sale, final reduction to clear - £126. Just happened to be passing and my wife persuaded me to go in. Wasn't even looking for a macro lens at the time. Though having said that, it's rarely been off my camera since................ until today when my DA* 50-135 arrived.