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Forum: Post-Processing Articles
08-10-2017, 06:29 AM
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Thank you for the detailed description of this very interesting work. I think you clearly showed that one can tweak via profile to minimize differences between the two types of sensor. It does not appear, to me anyway, that CCD is inherently superior to CMOS in terms of color. I had a K10 but found that even a K-x was far better for my type of photography. However, I am still the limiting factor.
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Forum: Pentax SLR Lens Discussion
08-10-2017, 06:09 AM
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I have both and they were bought about the same time. The Sigma 17-50 was a replacement for a Tamron 17-50, which was kind of falling apart. Based on my experience, I rank the Sigma 17-50 better than the 16-85 in center sharpness. As a matter of fact, it is incredibly sharp and capable of very high resolution when used with pixel shift. The Pentax 16-85 is more even across the frame; it is definitely better at the corners. The Sigma is f/2.8 and quite usable at that; so the Sigma is better for certain conditions such as low light or better subject/background isolation. The Pentax is WR and has a wider, very useful zoom range. Both of them focus fast and quiet. Since I only shoot raw, color is a non-issue.
I honestly cannot say one is better than the other for all situations and that is the reason for having both.
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Forum: Pentax SLR Lens Discussion
07-19-2017, 12:30 PM
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I have 85 mm, 14 mm and 8 mm. They all have the "A" position on the aperture ring.
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Forum: Film Processing, Scanning, and Darkroom
07-19-2017, 05:36 AM
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I used to process B&W for about 20 years but stopped about some 20 years ago when I lost interest because I have other priorities. My experience with water quality has not been so fortunate as some of you. I was able to positively correlate problems with water sources. As a scientist, I eventually invested in constant temperature water baths, pH probe, and a RO system with ion exchange bed. When I switched to digital, I also switched to digital dark room. The only thing I kept was the RO water system.
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Forum: Film Processing, Scanning, and Darkroom
07-18-2017, 01:45 PM
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Quality of bottled water varies greatly from no treatment what-so-ever to distilled water. Given that you don't want to install purifier, I would opt for water that is labelled DISTILLED.
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Forum: Film Processing, Scanning, and Darkroom
07-18-2017, 10:37 AM
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Water quality can play a big role in the end result. Most if not all cities use chlorine to disinfect water. This treatment raises the acidity of the water. Most cities then use a lime bed treatment to neutralize the acid. This lime treatment, however, can increase the hardness of the water. Depending on the hardness of the water, it can leave behind a grainy layer of deposit. Film developer typically requires a high pH or alkaline condition, an acidic condition can therefore impede with the reaction. A stop bath is essentially a rinse in acidic condition.
The use of reverse osmosis (RO) water as TomB_tx suggested is a very good route to purify water. If you are still concerned with the acidity of the water, you can pass it through a mix ion exchange bed which will produce the most consistent quality of neutral water.
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Forum: Pentax SLR Lens Discussion
07-17-2017, 05:48 AM
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I have invested over the years on more lenses than I need. So right now I don't want (not need) to buy any more lenses just for the sake of spending money. As a matter of fact, I sold 5 lenses recently because I have not touched them for more than 5 years. I acquired a second system for travel.
On the other hand, if someone hands me 2 grand to spend on K-mount lenses, these are two: Pentax 15-30 (FF) and Sigma 18-35 (APS-C). They are totally redundant in my situation, however.
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Forum: Pentax K-1 & K-1 II
07-13-2017, 10:33 AM
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When I do use pixel shift, which is quite often, I tend to be very selective. That means I usually only have a few files to process. I have no problem using PDCU and I only use PDCU to process the raw files into TIFFs which are then imported into LR for additional adjustments.
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Forum: Pentax SLR Lens Discussion
07-05-2017, 10:08 AM
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I have both Pentax 16-85 and Sigma 17-50. I have no reservation as far as IQ is concerned for either lens. The Sigma is extremely sharp in the center while the Pentax is more even across the frame. And the Sigma is f/2.8 which has some advantages in some situations. You can get the Sigma at a lower price than the Pentax. But Pentax is WR, wider 16 mm, and longer FL.
I also had 18-135 that was replaced by the 16-85, my copy is significantly better than 18-135.
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Forum: Pentax SLR Lens Discussion
07-05-2017, 10:01 AM
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I had a copy of 18-135. While it is not bad overall, I never like it much other than the focal lengths. Was looking at 20-40 for the WR. The very limited range is not too useful as a zoom lens and 20mm is not wide enough for me. Moreover, reviews seem to suggest a split personality. I ended up replacing the 18-135 with 16-85. Have been very happy with the performance. The wider 16mm is a great as I don't need to change lens as often now. I just wish it were a constant f/4.0. I have taken quite a number of pictures with K-3II (w/ PS) and they can stand up to pixel peeping.
If you don't mind the limited zoom range, consider the Sigma 18-35.
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Forum: Film SLRs and Compact Film Cameras
05-05-2017, 05:20 AM
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Learning can be hard, objective criticisms are necessary part of learning. I would not mind being banned if I had intended that to be personal. Commenting on technique is fair game. Not expressing an honest opinion is at a minimum not helpful and lying in the worst case. All of the responses addressing me have been personal. If you can't take any criticism, find another hobby.
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Forum: Film SLRs and Compact Film Cameras
05-04-2017, 10:03 AM
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It is on the front page of this site. Anyone can see. Why do you feel so offended. It is an objective assessment. Not personal. If you cannot take it negative comment, tell this to site management.
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Forum: Film SLRs and Compact Film Cameras
05-04-2017, 07:25 AM
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Hate to spoil the party. Not likely to get me (or anyone else) excited about going back to film. Hopefully the actual images on film are better than these. I used to develop my own B&W film last century before converting to digital.
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Forum: Pentax News and Rumors
04-20-2017, 05:12 AM
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I hope K-3II behaves the same as K-3, which is listed.
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Forum: Pentax K-1 & K-1 II
04-12-2017, 11:38 AM
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An alternative is to buy a portable dvd burner. They are cheap.
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Forum: Pentax K-1 & K-1 II
04-11-2017, 05:27 PM
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I experienced a similar camera bag failure but the contents did not suffer at all. Inside the bag, I had a K-3II with Pentax 16-85 attached, Sigma 8-16 and Pentax 50-135. The bag was a Lowepro Sling. Very well padded inside. May be you need a better bag next time.
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Forum: Pentax K-1 & K-1 II
04-04-2017, 04:39 AM
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Very nice. Are they stitched?
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Forum: Pentax SLR Lens Discussion
03-24-2017, 08:53 AM
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I don't have the Pentax but love the Sigma 70. My totally baseless guess is Y=Sigma.
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Forum: Pentax SLR Lens Discussion
03-22-2017, 06:51 AM
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I have tested a Tamron 1.4X TC with a number of zoom lenses, the HD 55-300 and Sigma 100-300 f/4 were included. K-5IIs was used as the camera. Under very controlled condition, results were unexpectedly good based on my (fading) memory. The degradation in IQ was negligible with the Sigma 100-300 at all focal length; the 55-300 was only a touch worse at the long end. AF was much worse for both lenses. I have yet to used either combo in a real situation and doubt I would do that. I bought the TC because of LBA, not because of need. Besides, I am more interested in WA or UWA than tele.
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Forum: Pentax Camera and Field Accessories
03-18-2017, 11:50 AM
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I like to use the one that comes with the camera because I can use it as hand strap or neck strap. With a hand only strap, the flexibility does not exist.
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Forum: Pentax DSLR Discussion
03-16-2017, 07:15 AM
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Designing and developing high quality finished products take years! Getting the concept is relatively easy but fine tuning it is the time consuming part. Software development has shaved substantial amount of effort from lens design. It has leveled the playing field and the reason why Sigma and Tamron are both coming out with high quality optics.
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Forum: Pentax DSLR Discussion
03-16-2017, 06:56 AM
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I think it has a lot to do with patent coverage. The primary purpose of patent is to block competitions from using the technology. Chances are Nikon and Canon have extensive patents that block each other; consequently these patents also block Pentax. Pentax has to either find a niche in the crowded space or license it from competition. How likely can Pentax out fox competitions with limited fund? If Pentax goes the licensing path, Pentax is likely given technology that is 1 or 2 generations older.
Mirrorless are completely different since they don't use mirror and so they are completely outside of the patent space of Canon and Nikon. BTW, it does not mean mirrorless has to reinvent from scratch. In fact, mirrorless can use the same existing logic and technology already developed if these patents do not explicitly cover mirrorless. It is also a likely reason why both Nikon and Canon are slow to join the mirrorless because they are blocked out by Sony, Olympus, Panasonic, etc.
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Forum: Pentax K-70 & KF
03-14-2017, 06:12 PM
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I have K-3II as the main body and also e-pm2 when I need something small. e-pm2 is actually very good but cannot touch K-3II especially when pixel shift is used. The main reason for getting e-pm2 is size. The lens to go along is Panasonic 12-60, which is exactly equivalent to Pentax 16-85. So, the answer is it depends.
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Forum: General Photography
03-13-2017, 12:17 PM
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There is no question that the thief is either competitions conspiring together to stop Pentax from dominating the market or poor Pentax user lusting over the equipment :)
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Forum: Pentax DSLR Discussion
03-02-2017, 07:28 AM
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You may want to consider K-70 and Sigma 17-50 f/2.8. I don't have K-70 but do have K-3II. There are reports suggesting that K-70 has a slightly better sensor than K-3. K-70 has an articulating screen which K-3II does not. Sigma 17-50 has HSM drive which is fast and silent. IQ wise, the Sigma is better than Tamron. I had both at one point, but I kept the Sigma. I never have any concern with Pentax dSLR build quality. The only consideration is louder shutter/mirror mechanism on the K-70. I had a K-S2, but was not bordered by the noise. YMMV however. FWIW, I am considering a K-70 as a backup for the K-3II. K-P is also a candidate but I cannot justify the cost difference, not at this point anyway.
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