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Forum: Pentax K-3 & K-3 II
03-20-2016, 08:39 AM
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Sorry, but this is incorrect relating to how the range of Sharpness, Fine Sharpness, and Extra (Fine) Sharpness work (on JPEGs only).
Whichever of the three ranges is selected, the sharpening or un-sharpening applies similarly across the entire image. Essentially it serves as a "radius" setting for the sharpening requested. Personally, I prefer adding a small amount of Fine Sharpening - +1 or +2. (I also prefer using Natural instead of Bright - for more realistic appearance and to avoid red blowout which is common in the Bright default setting.) As you go further down the line to Extra it tends to give you the appearance of greater contrast - such as micro-contrast or structure (a Capture One setting) - as opposed to coarser resolution sharpness at the wider radius. If you are depending on JPEGs for posting or printing (I use them only for reference unless a quick turnaround job is being requested), the best look will depend on the particular situation and lens selected.
This link will show you the visual effects (best to compare -4 and +4 on all three ranges to see the full difference):
Pentax K-5 Sharpness Settings | Neocamera |
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Forum: Pentax SLR Lens Discussion
10-21-2015, 05:43 PM
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A lot of Pentax bias in this thread. The majority of my manual focus lenses are Pentax, but most of the Samyang (Rokinon, Bower, Vivitar, etc.) lenses are superior to the their older Pentax counterparts. The 85 and 14 are especially fine FF lenses, as is the 8mm as a crop format lens.
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Forum: Pentax K-3 & K-3 II
07-06-2015, 08:57 PM
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A lot of this debate comes when looking at the images at the pixel level. Yes, the additional smoothing in the K-3 series will yield a less noisy look magnified, but we are talking about 50% more pixels and added softening on the K-5 series, so the comparison isn't exactly fair. The K-3 also demands a bit better exposure control than the 16 mp sensors, so an underexposure in low light is a problem for the K-3. Ultimately, for normal viewing, low light images properly exposed and processed to full potential goes to the K-3 - as all the tests have indicated (Here, Dxo, etc.). Admittedly, the K-3 demands a different processing technique stressing a bit more noise reduction, less general sharpening, and greater micro-contrast enhancement to get the most out of the 24mp sensor. Once that is figured out, the advantage is very apparent.
For anyone claiming superior low light performance on the K-3ii vs. K-3, you are going against what has been stated by Pentax and the apparent baseline for the essentially similar sensors. Some real-world comparisons would possibly add credence, otherwise it seems that such a claim is based on hopefulness.
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Forum: Pentax SLR Lens Discussion
11-10-2017, 10:52 AM
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Those are stunning photos. The FA 35 is very good overall, but at the close focusing on the cat, I don't think it could quite match the pop of that shot. At normal distances, the FA 35 is very good. Also agree, it tends to be just a bit warm - which might or might not be to your liking. Just as the macro has a reputation for good quality wide open, the FA is good at f/2 and excellent across the entire field by f2.2 - possibly the best lens I have at the aperture. Both lenses are capable of yielding a 3D quality. I don't think there is any question that both these lenses are considerably above average - especially for the price, but their strengths are somewhat different. As an absolute macro (1:2 or closer), I don't think 35mm is a preferable length - especially if you are planning on shooting critters. However, that isn't the main strength of that lens, IMHO, as it clearly performs extremely well as a "normal" lens.
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Forum: Pentax SLR Lens Discussion
11-05-2017, 10:55 AM
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I'm sure you meant that standing further away "increases" DoF - that is, it becomes less shallow with distance. Otherwise, the point is valid.
What folks tend to forget is that the smaller the sensor the greater the magnification needed. That's where you sense the loss of resolution. Of course, the image circle of a lens has nothing to do with that.
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Forum: Pentax SLR Lens Discussion
11-05-2017, 02:33 PM
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Interesting... I have the Tamron 28-75 lens in Canon mount where it was used both for crop and FF needs. Photozone indicates that the lens performs especially well on crop, but the edges and corners have too many issues for FF. I found that it was really fine at FF when stopped down to f/4, but not adequate wide open (no lens I've owned has dramatically improved so much in a single stop). I'm just the opposite in terms of my shooting needs. I really enjoy lenses that go from wide to mild telephoto - with "normal" roughly in the middle. Starting at normal feels very limiting to me.
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Forum: Pentax SLR Lens Discussion
09-19-2017, 07:13 PM
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Wow, I thought mine took the cake when it comes to turning a blind eye. Pretty sure I couldn't get away with flashing a 645z without a pointed question. And, if the question was, "What did that cost?" doubt that saying "less than half what the Hassy version costs" would get me out of that pickle.
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Forum: Pentax SLR Lens Discussion
08-30-2017, 07:23 PM
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It seems that the fast 85s are the Nirvana of challenging focus shift experience, but all lenses have some form of focus shift (no matter how minor). The main criticism of the Zeiss Planar, Nikon, and even the lowly Samyang 85 designs are entirely consistent - focus shift is a factor requiring (minor) compensation. Work within the limitation. Stop down to focus precisely accordingly. Use live view magnification for precision stopped down focusing for exacting results, and understand that a very limited range of apertures have a meaningful impact. From f/4 and beyond on a crop sensor (f/5.6 for FF), the DoF eliminates the need for absolute precision related to focus shift.
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Forum: Pentax SLR Lens Discussion
08-07-2017, 09:00 AM
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A common mistake shooting landscapes with an UWA (14mm and wider on crop, and 21mm or wider on FF) is that the lens designs tend to have considerable field curvature. Even moderate wides, such as the Tamron 17-50, can have extreme field curvature at the wide end. So, shooting at no less than f/11 will yield the sharpest results more evenly, and f/16 is often optimal.
Another major concern, especially when shooting faster lenses, is focus shift. The Samyang 85mm f/1.4 shows considerable focus shift in the f/2-3.6 range, so critical work demands focusing with the lens stopped down. Past about f/4 the DoF pretty much eliminates the issue.
Understanding the limitations of a lens and the situation is a big part of the process of getting the best images.
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Forum: Pentax SLR Lens Discussion
07-28-2017, 12:51 PM
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The Tamron and Sigma models you have are not digital era designs - so considerable CA issues are very evident, especially on the long end (Sigma has a newer APO design that is somewhat better). The Pentax 55-300 4-5.8 is definitely sharper than the third party offerings in the 250-300 range. However, the much lower CA is probably even more noteworthy because even the best RAW converters can't remove massive CA without resulting image degradation. While the non-PLM 55-300s are optically similar, the WR version has a better build more likely to hold together than earlier builds and HD coatings yield a very slightly higher contrast.
While the 60-250 is a very good optic, keep in mind that severe focus breathing reduces reach considerably even at medium distances (20-40 feet or closer). Focusing is very slow. The lens will not perform as well overall as the 55-300 when shooting wildlife, and is not adequate for shooting birds in most situations.
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Forum: Pentax SLR Lens Discussion
07-18-2017, 10:07 PM
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So, we have it... They share an awful lot in common regarding the optical groupings and diaphragm design. They are just slightly different because the FA has less light fall off, the front objective is larger, it is a half stop faster, resolution is more consistent edge-to-edge wide open, the coatings are different (by most reports), metal ring, physical aperture ring; the DA has less measured distortion, is considerably lighter, and has greater contrast (by most reports). Other than the several fairly significant physical and imaging differences, they are quite similar. Certainly more similar than the macro, but we have a pretty good idea that they are not essentially similar.
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Forum: Pentax SLR Lens Discussion
07-18-2017, 01:44 AM
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The front element is 3.5cm on the FA35, and just under 2.4cm on the rear.
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Forum: Pentax SLR Lens Discussion
07-14-2017, 10:16 AM
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hekr responded that the PLM works OK with the 1.4x if used on the KP/K3 modules that can handle lower light. Still, the combination of a consumer lens - that isn't really any sharper than the earlier 55-300 - with a DA converter designed to work with faster lenses, and yielding an effective f/9 wide open doesn't make much sense to me unless you are planning to use the combo in nothing but bright lighting.
The Tamron 70-200 is plenty sharp enough to handle a DA converter well, but the combined reach is only 280mm - so only picking up the stop of aperture and edge sharpness, but no gain in reach.
Perhaps the Tokina 400 prime is the best solution. I would advise against the Tokina 80-400, though. I found it unacceptably soft (shot on Canon).
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Forum: Pentax SLR Lens Discussion
07-12-2017, 03:57 PM
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I haven't owned either, but have often looked at photos taken with each. This would be my thought based on the aesthetics, and reinforced by the photos posted by LeRolls. Not sure I have seen anything from Sigma to indicate an ability to achieve that look, but that might be somewhat due to the processing abilities and desire to achieve that look.
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Forum: Pentax SLR Lens Discussion
05-03-2017, 07:44 PM
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Goudge makes a good point overall regarding nodal point and other variables, but the last point regarding the "advantage" of close up lenses offering brighter images is pretty much like saying the light from a nearby atomic bomb detonation is brighter than anything you've seen previously - or quite obviously ever again. The compromises of sticking a simple magnifying glass in front of a good lens are much greater than the other compromises related to adapting a non-macro lens.
Every lens design responds differently, based on issues related to diaphragm placement, nodal point, other overall optical design considerations, and coatings. For some lenses, reversing is a good option, but not often. Use of a quality TC is often a good compromise, especially for standard lenses in the 50 to 85mm range. Possibly the best overall "compromise" is the extending TC, such as the Vivitar 2x macro. I have the better green numerical version (confusingly designated P/K-A R-P/K but does not have the Ricoh pin problem): optically very good as a continuously variable extender - and not bad as a TC. Short of going for a dedicated macro lens, it probably qualifies as the most versatile and simple solution to yield good results.
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Forum: Pentax DSLR Discussion
04-08-2017, 08:44 AM
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That's interesting to see. In my days of reporting on and shooting sports facilities years ago, I was aware that MLB had been trying to get matching rules - and thought they would be there by now. I think 12 inches is a reasonable standard that allows for some discretion (although bringing the lens in it will be compact, but in use it might expand beyond 12 inches - very tough to enforce). As I had said in the earlier post, the FF rig gets to be pretty large and could cause distraction. The K-3 rig probably is the better choice. Shooting from the stands can be fun and interesting, but you just have to be satisfied that you won't be getting stunning close-in results. My best shots were always the environmental ones, wide angle showing life in the stands.
If you are shooting a night game, the best shots can come in the early innings when you get a nice combination of sun and ballpark lighting - softer shadows than midday and enough light overall. June and early July games give you that added light, especially in the northern states.
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Forum: Pentax SLR Lens Discussion
03-30-2017, 06:26 PM
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---------- Post added 03-30-2017 at 08:31 PM ----------
We have very similar views on the various lenses, but maybe not so much regarding the Tamron. The Tamron 28-75 is a fine lens - having shot it extensively (long ago) on Canon FF and crop - and it is a better IQ lens on crop, but I don't know if I'm as much of a fan regarding the equivalence - roughly normal perspective to 120mm on Canon crop at 1.6x. The lens simply isn't sharp enough until you stop down until at least f/3.5, and f/4 at the wide end. It is a lens I could get along with on FF, given its relatively small size, but the Sigma 17-50 is simply more capable on APS-c - at least when comparing old Canon (Tamron) to newer Pentax (Sigma) - probably pretty unfair, I guess.
As for the images posted by Denis (Tatouzou)... I haven't seen that quality wide open from the 18-135 in any images posted previously. Perhaps the colorful scenes and bright light contributed to the overall quality, but you certainly have found the sweet spot for that lens. I've seen a lot of middling images posted with that lens, but you obviously are very good at getting the most out of it, and realizing that you can't go too far toward the edges for your focal point.
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Forum: Pentax SLR Lens Discussion
03-24-2017, 10:32 PM
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It is a bit disappointing when the OP has a particular mindset, skeptical of all the likely options. It might not be worthwhile trying to explain better options if the mind is closed. It doesn't help to not list your priorities (such as lens speed, zoom range, need for WR, build quality, overall weight and handling, constant aperture, etc.).
The Tamron 17-50 can be a stunning lens in the right conditions. I've come close to buying it a few times, but the red flags help to explain its relatively low selling price. My brother bought one, and it fell apart on him. The extreme field curvature issues in the wide end explains most of the erratic focus problems.
The lens that finally got me is the Sigma 17-50 which is deeply discounted compared to its earlier selling price. This is a lens that performs very well in almost every situation. It takes a bit of time to understand how to get great shots out of it. I'm liking it more over time, as I find where it excels. Clearly it is adequate as an everyday lens because it really covers the key bases well, and at times you can get stunning shots. It will perform as well as a fast prime shot at close distances around f/3.5. The background blur can be very good in those situations. It isn't so great as a landscape lens, or generally in the mid-range apertures where the near out-of-focus can be quite busy. All zooms have their weaknesses, but even at its worst the Sigma qualifies as a more-than-adequate everyday lens. It really is considerably more versatile than the Tamron, and it is built to last. Some people feel it is a bit heavy, but that is true of all better built f/2.8 zooms.
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Forum: Pentax DSLR Discussion
03-22-2017, 10:30 PM
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That's a fair question that I swear was answered at some point, but not entirely sure of the value in trying to dig it up. Instead, I'll offer my perspective.
AF.S should yield the best focus for a single static shot.
AF.C will yield the best results for a sequence of shots, and especially so if your intended subject is moving.
In theory, AF.A will pick the best of the two modes by determining what the shooter (and body) is doing. In practice, I have found it not useful on the K-3 or older units; I'm yet to find skilled users who prefer it.
Three Custom Menu modes on the K-3 (#s 15-17) further determine how the camera responds regarding tolerance for out of focus shots, as opposed to continuous high-speed image capture regardless of focus. I am yet to find a situation when the K-3 (or other bodies) has tended to hesitate too much; I still get a fair share of not-quite-sharp images when using the highest focus-priority setting. From the standpoint of those of us who might be getting paid for our best shots, I don't see a reason to do anything other than focus priority.
#15. AF.S Setting - 1. Focus Priority.... (on occasion I might forget that the Quick Menu setting is in AF.S, so better safe than sorry regarding focus).
#16. First Frame Action in AF.C - 3. Focus Priority.... this one is pretty critical based on shooting style; generally I don't expect my first shot to be at the peak moment, and I expect myself to be prepared to start shooting before the maximum impact moment. Others might have a different shooting style, though, and want the first shot fired whether it is in good focus or not.
#17. Action in AF.C - 1. Focus Priority - Continuous Focus tracking takes priority.... Any alternative kind of reminds us of the terribly not-PC Stevie Wonder shooting a tennis match for Canon TV parody.
Almost as important is the direction to the camera on what AF sensor array will work best for any given situation, and the skilled shooter will want to understand the context in making the decision. Few threads have addressed the issue, and the manual is not at all helpful. The K-3 has a total of seven modes available, spot, four SEL (noted in bold) and two AUTO. Most of us probably pick single spot SEL and get good results in the vast majority of situations. However, for controlled action shooting (where moves can be fairly easily predicted) such as, um, this guy weaving on his bicycle through a sidewalk cafe (cough, cough) - SEL-9 is a great option; SEL-25 is better for action where you really don't know where the next move is likely to be (soccer is a good example). I am not a fan of using the two edge sensors in SEL-27 because they are not very accurate. As for the two corresponding AUTO settings (9, 25), they will not track, but will best guess (most often a defined object closest to the camera); not a really useful function in my experience.
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Forum: Pentax DSLR Discussion
03-17-2017, 08:15 AM
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Due to the relatively large barrel distortion of this lens design, actual focal length is probably closer to the 13-13.5 range. In fact, the rebadged Vivitar version lists the lens as 13mm. Users of the 15-30 have indicated that the difference in view at 15mm is substantial. My preference has been to designate the 12mm setting, as I would rather be conservative instead of over-correction. It's unfortunate that Pentax hasn't implemented the ability to manually enter an exact setting as was done on the Q bodies.
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Forum: Pentax SLR Lens Discussion
03-10-2017, 02:14 PM
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I pretty much use my zooms for situations when I need flexibility. If I have a situation where I'm controlling the environment (portrait session, landscape shooting, night club, etc.), or need a low profile such as street shooting, I'm using primes. Not that everyone thinks this way, but the utility factor should play some role.
For a long time, I thought issues with coloration and saturation always can be addressed. Even as processing software (and especially raw converters) have progressed, getting the look readily obtained from especially distinctive Pentax optics - especially lenses such as the DA40/xs, FA 35, or 35-105/3.5 - isn't easily recreated by some very fine lenses that rarely show a special pop. I have the very fine Sigma 17-50, and perhaps in time I will find ways to get the very best out of it, but the lens simply doesn't saturate as well as the better Pentax lenses.
By the way, the FA 35 is a far cry from the DA 35 - they really provide a different look no matter the relative similarity in optical formula. The DA 35 might be a tad sharper (at least in the center) with higher saturation, but the FA 35 is markedly superior in the corners and renders far-more naturally (at least to my eye).
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Forum: Pentax SLR Lens Discussion
01-07-2017, 04:17 PM
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I have never seen one of the f/5 lenses, and have no idea about their quality. I also would have to guess that it is older because I am very well aware of the Tokina RMC lenses from 1978 to 1984 - as we sold a lot of them (Brown, Black, then Ritz photo stores). Tokina went to smaller, variable aperture tele-zooms in the early 1980s. One touch was the rage in those years, but I think the two-stage designs are generally superior (and the lens makers slowly came back to that).
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Forum: Pentax SLR Lens Discussion
12-29-2016, 01:46 PM
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I think all the comments so far are fair. You really should make the decision based on your overall shooting needs, as opposed to the optical concerns on lenses that all measure up fine on IQ.
In differentiating the Sigma and Tamron 17-50s, I agree with Audiobomber overall - and have a couple other thoughts, as well. I purchased the Sigma once it got down to $400 or a bit below. The build is significantly better than the Tamron (my brother had that one); his loosened up a lot under less than heavy use, and Tamron did not see the problem as a warranty issue. I think that's the main issue. Also, the Tamron is known to have considerable field curvature at wide angle / wide aperture. It might not be great for landscape work unless stopped down considerably.
I haven't had the Sigma long enough to pass strong judgment yet. It does everything well, but I'm yet to get excited by a stellar image (my problem - haven't shot anything all that interesting with it yet). I'm still getting used to the overall bokeh, coloration, and saturation, and how best to process the RAWs compared to the Pentax look. Size and weight hasn't bothered me (but I tend to be OK with larger, heavier lenses). It balances fine, and isn't front heavy - at least on the K-3.
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Forum: Pentax K-3 & K-3 II
12-26-2016, 03:37 PM
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While I understand the concern about shooting low ISO if possible, I have found that the overall need for at least some margin of error in shooting the K-3 requires f/4-6.3 for the best results. So, shooting ISO 3200 is pretty much a necessary evil. I'm not fond of shooting below about 85mm because it becomes difficult to isolate. My favorite lens for basketball is the lowly Takumar 70-210 - which turns out to be rather capable even when shot wide open (up to about 180mm anyways). The lens is impressively responsive on the K-3. In general, with the K-3 having a very strong screw drive motor, I think screw drive will be at least a bit quicker than any of the fast electronic drive zooms.
The photos in the album linked below start with one DA 50mm shot (at f/2.5), and the rest of the shots are taken with the 70-210 at the middle-to-longer lengths (but not all the way out to 210).
Gophers vs. Northern Illinois - James Robins - Powered by Phanfare |
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Forum: Pentax SLR Lens Discussion
12-09-2016, 11:42 AM
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Please read my entire post, and pay attention both to my explanation that the K-1 pixel density is similar to the 16 mp crop (less dense), as well as the differences when considering comparison to FF. You have corrected me in such way that you are confirming what I originally stated.
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