|
Forum: Pentax K-3 & K-3 II
07-28-2014, 04:04 AM
|
| |
Both Pentax Q and K-3 which I own has similar behaviour. The Q actually replicates every frame 5 times, while the K-3 does 3. Pentax should modify the firmware so that the user could select the number of replication with the possibility to completely disable it. Yes, you can removed them in VirtualDub, but that is extra work. Smooth timelapse can only be achieved with no replicated frames. The user should also be able to select the resulting fps in my opinion, since this is only a matter of a single parameter value in the AVI file container.
|
|
Forum: Pentax SLR Lens Discussion
08-12-2013, 12:13 AM
|
| |
Just for the records: googling the issue with shorter max focal length than expected gained me the knowledge that zoom lenses (most of them) tend to become shorter (in focal length) the more narrow you focus: this is due to design issues. Primes do not in general have this behavior. So, zoom lenses in general have the stated focal length (+/- 5%) only when focussed at infinite. And here the Sigma 17-50/f2.8 seems to fit well (just a tiny more wide than the FA50/f1.4 at infinite). I'm quite happy with these findings. :D
b.r. Arne
|
|
Forum: Pentax SLR Lens Discussion
08-09-2013, 12:10 AM
|
| |
Thanks a lot! I found it is rather shorter in the long end than my FA50mm/f1.4, but I guess, this is normal, I was somewhat expecting it.
Took some test images last evening, and compared shots with both DA21/f3.2, FA50/f1.4, and kit lens DA18-55/f3.5-5.6WR. To be honest, the Sigma sharpness took my K-7 to new dimensions: the kit lens was left in the dust by the Sigma beast. It competes with the primes either on par or even better. Yes, I miss somewhat the ability to quick shift focus (while in AF, as DA21 and DA18-55 have), but I can live with that. The short throw of the manual focus I actually find ok, perhaps a plus, a long throw would have been much worse I think; no problem with focus ring dampening either. The lens weight and size I find balances well on the K-7 body, and it looks very nice, too.
b.r. Arne
|
|
Forum: Pentax SLR Lens Discussion
08-08-2013, 08:58 AM
|
| |
Actually, a local store had it on shelf with the amazing price of 2990,- NOK (should be around 499 USD). Did some testing with my K-7 and found it was backfocusing. Did AF adjustment in body at +5 and it seems to be spot on at whole range now, but I guess a little early still to fix that setting. It will be tried thoroghly in a wedding next weekend, so hopefully I am as excided also after that time. Thanks for all input to my questionare :) Will post some images if I am satisfied with them!
b.r. Arne
|
|
Forum: Pentax SLR Lens Discussion
08-07-2013, 12:17 AM
|
| |
Hi all,
Thanks for all answers to my request on Sigma normal zoom. Some final questions from me, if anybody can comment on them:
1. It seems that the 17-50/f2.8 for Pentax mount is having its OS capability in place, while in the 17-70 lens with Pentax mount it is removed. What are the pros and cons of this? (e.g., is it possible that the 17-70 without OS actually perform better resolution wise than the tested samples with Canon and Nikon mount?)
2. I see some complaints about the short manual focus movement in the 17-50 lens, and that its has low friction, making it difficult to focus manually. Is the 17-70 lens much better in this respect? And, is it true that the 17-70 lets you "quick-shift" the focus manually when AF switch is set to AF?
best regards
Arne
|
|
Forum: Pentax SLR Lens Discussion
08-07-2013, 12:08 AM
|
| |
Thanks a lot for these reviews, I did not find these myself. Yes, the corner resolution is really a different cathegory, I agree. Hm, perhaps I am reaching a decision here...:rolleyes:
|
|
Forum: Pentax SLR Lens Discussion
08-06-2013, 11:51 PM
|
| |
Yes, I am aware of the weight difference, and also size, I am a bit worried about 565 grams...
|
|
Forum: Pentax SLR Lens Discussion
08-06-2013, 01:56 PM
|
| |
Hi!
I'm looking for an upgrade of my DA 18-55 kit lens (WR); with my K-7 I use mostly the DA21/f3.2 since it is tack sharp and reasonable fast and wide enough to my likings, and, its small and light. I know going into the 17-50 or 17-70 zoom range, asking for fast and sharp glass, it will be much heavier than the kit lens or the DA21. Due to performance and price consideration, I have landed on the two Sigmas listed in the thread title. (I have read the nice reviews of the lenses in Pentaxforums, thanks, great review!) Actually, in Norway the 17-50/f2.8 is since July cheaper then the f2.8-4.0 lens, about 12% cheaper. I do not know if it will last, though. Since the 17-50/f2.8 introduction price, this is half the price!
What I want to ask the audience is which one is really the sharpest? According to the test results in DxOmark, the 17-50 lens drops in sharpness wide open in the midlle zoom range, while the opposite is the case for the 17-70 lens. Many users complains further on the loss of sharpness, or is it focus, of the 17-70 lens at 17mm, focused at infinity.
Questions:
* Is it true that the focus can be manually corrected with focus switch in AF position of the 17-70 lens, but not on the 17-50 lens?
* How os the weight balance of the two lenses on a K-7/K-5 body?
* Flare: is the flare really bad on the 17-50 lens compared to the 17-70?
* How is the built quality in comparison?
* If the 17-50 lens can be bought cheaper than the 17-70, is the situation perhaps a no-brainer?
I hope someone find the time to answer some of my questions.
best regards
/Arne
|
|
Forum: Pentax News and Rumors
01-24-2008, 10:29 AM
|
| |
1.6Mp images in 20fps is damn close to shooting 720p HD: 720p frames are about 1.0Mp at 25 or 30 fps. 1080p frames are about 2.0Mp. I hoped that Pentax would release HD shooting in K20D, but perhaps they have decided to wait until K30D...
|
