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Forum: Pentax SLR Lens Discussion 03-12-2017, 12:41 PM  
DA* 300mm F4 vs Pentax-F* 300mm F4.5 autofocus
Posted By snostorm
Replies: 14
Views: 911
The DA* 300 is both larger and heavier than either the F* or FA* 300/4.5. When the DA* was introduced, I tested one side by side with my standby, the FA* 300/4.5 and found the new lens a hair sharper, but decided to pass because of the extra bulk and the fact that there were no TCs available at the time that would AF adequately with the new lens. The only one that does is the HD AW 1.4x that was introduced later.

I shoot my FA*300/4.5 mostly handheld, with or w/o TCs extensively so the lack of a tripod foot on the lens is irrelevant to me, and I like the longer lens shade on the FA*, even if the hood is a little fussy to mount. I can use my Tamron 1.4x, Sigma 1.4x, or Pentax 1.7x AFA with my FA* 300/4.5 with AF, but the DA* will only AF reliably with the Pentax 1.4x HD AW (which is pretty pricey) and the AFA.

Personally, I'd consider either a CLA of the lens you have, or look for an FA* to take its place.

Scott
Forum: Pentax SLR Lens Discussion 09-02-2016, 02:20 PM  
Choosing a Pentax Long Telephoto
Posted By snostorm
Replies: 21
Views: 1,711
Hi dakotapix,

For me, a decision between the four lenses listed is pretty much a no brainer, but that's me. Although the A* 600/5.6 and DA* 560 are realistically usable from a portability standpoint for me, the MFD of @ 15 feet makes them unusable for what I like to shoot. The FA* 600/4 is obviously an exemplary lens, as is the FA* 250-600/5.6, but the 13+ lb weight would not be manageable for me, and the 600's 13 foot MFD would be an additional deal breaker. I like to shoot handheld and usually from 8-15 feet optimally. . .

The DFA 150-450, though a bit short, is light (4.4 lbs) enough to handhold effectively and focuses down to @ 6 feet. It's sharp even wide open and fast focusing. It's not my favorite, which remains and FA* 300/4.5 + F 1.7x AFA, which gives me 2+ lb 510mm f7.7 with built in focus limiter and very quick AF lock (albeit with some AF limitations), but the DFA 150-450 gives me a quality WR alternative if conditions dictate.

Scott
Forum: Pentax SLR Lens Discussion 08-08-2016, 04:20 PM  
Replacement for my 55-300?
Posted By snostorm
Replies: 25
Views: 1,938
Hi AggieDad,

Maybe thinking a bit outside the box might be in order. Since you mentioned birds, and have a 150-500, I'm assuming that you are looking for a solution that gives you less hunting for this purpose.

I've been shooting birds with my Pentax DSLRs for over 10 years, and my main solution for this has been the F 1.7x Auto Focusing Adaptor. The 1.7x AFA was introduced with the first Pentax AF bodies to give AF capability to the faster MF lenses. Because of the physical length of the adapter to give it the AF capability, it also acts as a 1.7x TC.

At "normal" FLs like with a 50mm f2 lens, all you need to do is prefocus the lens to infinity and the lens becomes an 85mm f3.4 AF lens throughout the focusing range of the lens. All AF is done within the AFA, and any AF capablility of the lens itself is lost if you mount it on the AFA. Auto Exposure works with any "A" capable lens, and the AFA even automatically calculates the f stop that's recorded in Exif to correct for the TC effect.

With telephoto lenses, the range of distances where the AFA will obtain critical focus gets narrower, so the lens needs to be manually prefocused to within the range of the AFA. This essentially makes the AFA a focus limiter in addition to being a very competent 1.7x TC with AF capability with any K mount lens. There is no free lunch, so as with any TC, you also lose max aperture in proportion to the magnification factor, so you need faster (faster than f4.5 in my experience) max aperture lenses for reasonable AF reliability and speed in most daylight conditions.

What this does is cut down the hunting to only the range of the AFA's AF range, which is relatively short at closer distances with tele lenses. Also, because the focusing lens groups within the AFA are small and light compared to those in most lenses, screwdrive AF is very snappy with the AFA.

What does this mean for you? You can add an AFA to your kit for probably between $200-300, but you'll have to find a used one since they aren't made anymore. There are usually some available in the marketplace on this site. Even though your current DA 55-300 has a max aperture of f5.8 at 300mm, it's about f4.5 at 200mm, so by limiting the zoom, you should be able to use it with the AFA to get 340mm f7.7, and this should give you reasonably fast and accurate AF in most daylight conditions. You'll not be adding much size or weight to your kit, and in bright daylight, you might be able to get reasonable AF performance at even the longer FLs pst 200mm.

For future consideration, if you choose to seek better IQ or longer reach, it will allow you to consider MF lens alternatives that might be less costly. A good example might be a K 300 f4. You can probably find one for maybe 250-350 used. This will give you a sub 3 lb 510mm f6.8 AF lens. Better yet, get an A*300 f4 and get better optics and lighter weight, but it'll cost maybe $200 more. I use an FA*300 f4.5 + AFA most of the time as my main birding lens which gives me 510mm f7.7. It's smaller and lighter than any of the similar alternatives and adds ED optics which control CA/PF much better than the older lenses, and focuses to @ 6 ft. I've seen these available for $600-900 as well as the F*300 f4.5 which is optically identical. The F* and FA* 300/4.5 lenses are also Internal Focusing lenses so they stay the same compact size in use, unlike the Sigma zooms which get pretty long when zoomed out to 500mm. The fractional f stop slower is really of no consequence with the higher ISO capabilities of the newer Pentax DSLRs.

I could go on, but will stop here. . . just something els to consider. . .

Scott
Forum: Pentax Camera and Field Accessories 08-01-2016, 10:13 PM  
Tripod head
Posted By snostorm
Replies: 22
Views: 1,519
Hi Liz,

Excuse me if I'm telling you something that you already know, but any head will be infinitely easier to position and hold if you can balance the camera/lens on the head. This is most easily done by using an Arca Swiss compatible clamp and a suitable plate for your camera or lens. It's possible that the heads you already have might be at least adequate if you can balance the load, but better quality heads usually offer quicker and easier adjustments as well as better construction and more positive locking.

I always seek to balance my camera/lens on any tripod head I'm using, which include ball heads and gimbals.

Scott
Forum: Pentax K-1 07-08-2016, 07:40 PM  
Pentax K-1 Continuous AutoFocus Performance
Posted By snostorm
Replies: 135
Views: 14,032
Hi Quark,

Two other tips that could improve your keeper rate in addition to the settings suggested by Adam:

1. Always wait for the AF system to get an initial focus lock before starting your burst. Turning on the beep for focus lock might be useful. The difference this makes in percentage of keepers in AF C is significant.

2. To increase the speed of gaining an initial focus lock, start with the lens focused farther than the subject distance rather than closer. Pentax bodies seem to acquire focus lock easier moving in rather than going away.

These may not totally negate the disadvantages of Pentax AF C compared to better performing AF systems, but they should at least give it a fighting chance.

Scott
Forum: Pentax K-1 06-22-2016, 11:36 AM  
Sharpness inconsistency
Posted By snostorm
Replies: 12
Views: 981
Which implies either a mechanical problem with the lens or a calibration problem with the body/lens combination. Another cause at this shutter speed could be AF technique, which I think is what Quartermaster James was implying. Pentax DSLRs, with their relatively large AF sensors need more help from the shooter than some other AF systems with smaller and more discreet AF sensors.

Photographers who take the time to understand how an AF system works and learn how to work around their particular camera's AF system's quirks can get much more consistent AF performance regardless of which system is being used.

Scott
Forum: Pentax DSLR Discussion 06-17-2016, 06:11 PM  
K1 or K3-II when mostly tele?
Posted By snostorm
Replies: 56
Views: 5,236
Yes, these are in crop mode. The K-1 exif shows APS-C equivalent FL only when the shot is taken in crop mode, so it's easy to tell which mode the camera was in.

Scott
Forum: Pentax DSLR Discussion 06-17-2016, 01:40 PM  
K1 or K3-II when mostly tele?
Posted By snostorm
Replies: 56
Views: 5,236
Hi Norm,

I've also dealt with the AF limitations of all of my Pentax bodies since the DS over 10 years ago, and have upgraded bodies just to get the incremental improvements in AF performance that each has offered. When the K-1 was announced, I placed myself in the "probably won't get one" category as I assumed about $2500 in price, and there really isn't any "full frame advantage" for what I shoot (birds mostly). My "local" (70 mi away) B&M dealer knows what I shoot, and suggested I make the trip to try the K-1 despite my misgivings.

I made the trip, bringing my goto birding lens kit --FA*300/4.5 + F1.7x AFA (I have two of ea of these), my DFA 150-450, and my Tamron 28-75/2.8, FA50/1.4, and FA77 Ltd.

He let me use his own personal K-1 body, let me set it up however I liked, and let me shoot as much as I wanted in the store and outside in the parking lot. I brought my Asus Zen 15" laptop so I could play with the files there onsite. I alternated shooting with my K-3 and the K-1 with the FA*300+AFA and was surprised at how well the f7.7 max combo locked focus especially indoors compared to the K-3. Just chimping on the LCD, I could see that the K-1 was giving me better AF accuracy.

I was allowed to use an empty desk to play with the files on my laptop. Examining the images on the 4K laptop screen, I was pleased to see that critical AF lock was consistently more accurate with the K-1, especially in the lower light situations. I was shooting single shots, refocusing with AF each shot, even if I was shooting the same subject, as this is how usually I shoot when out in the field. The lower light AF performance is important to me because birds don't always choose the best lit branches to sit on, and often I'm shooting deep in the woods or in very shaded areas. I shoot opportunistically, so I need to be able to shoot in any lighting conditions that present themselves, and with an f7.7 max aperture, need all the help I can get from AF.

Also, with such a slow max aperture, high ISO comes into play more often than for most. With the K-3 I try to keep it under ISO 1000. With the K-1, I'm finding that 4000 takes about the same amount of work in PP to give me very good final images, and 5000-6400 might work as I'm still experimenting with some different techniques in PP.

I must admit that I don't shoot a lot of bursts, as I mostly shoot perching songbirds. I do always set up my shutter in Continuous High in case I want a burst, but burst speed is not a high priority for me, and 6.3fps in crop mode is easily good enough for my use -- and even 4fps in FF mode would not decrease my keeper rate.

Bottom line, the higher ISO capabilities plus the more versatile (lower light capable) consistently critically accurate AF made the difference, and I wrote a check and walked out with a brand new K-1. Another factor was the wider FOV VF, and the ability to change from FF to crop mode and back with a click of the dial. I've had enough situations where using a prime was a bit of a problem because I was too close, and stepping back wasn't an option because my subjects would spook.

Body weight difference is also not much of a problem for me though my aging joints do complain. I find myself picking spots that are easier to get to, so this is really not an issue. Also I'm not counting cost as an issue, though I realize that this is a high priority for many.

Bottom line, I'm getting more keepers than with previous bodies. I'm surprised at the higher percentage (maybe 20-30% better) of shots with acceptable or better feather detail because of the AF-S improvements in lower light and its decisiveness. I'm now able to get better IQ because I can shoot at higher ISO for faster shutter speeds and I can even stop the lens down for better resolution if I want.

I don't crop much for extra "reach". I generally shoot pretty close, which is why I prefer the 300mm+AFA which will mostly focus to @ 6ft as opposed to longer optics which typically have 10-13ft MFDs. I do shoot the K-1 in crop mode a lot because there's little sense to shooting in FF mode and capturing 20 or so MP that I'm going to crop out anyway. When I crop, 90% of the time it's very slightly for composition.

I'll include a few samples, but I've yet to develop a downsizing to 1400 pixels on the longside workflow that do the images much justice. Note that the first is at ISO 2500.

You've asked for samples showing IQ improvements in a number of posts, and I can understand this, but I would ask that you actually shoot a K-1 and compare it directly to what you currently shoot before stating that there would be no reason for a tele shooter to upgrade. It's fine to argue specs and try to imagine the differences in shooting experience and results, but it may be quite different in the actual shooting.

I'm very happy with my decision to get a K-1, and think you might actually be impressed if you tried one.

Scott
Forum: Pentax DSLR Discussion 06-05-2016, 11:11 AM  
Benefits of using K-1 with DA lens over K-3II?
Posted By snostorm
Replies: 20
Views: 2,114
For my purposes, the K-1 holds up as a legitimate upgrade for any Pentax DSLR (read APS-C) shooter, with the exception of those who will greatly benefit from the 24MP resolution alone in the K-3 series bodies or can't work with a bigger heavier body. Over the past 12 or so years, I've continued to upgrade my Pentax bodies to get either better high ISO performance or better AF performance (or both). Considered as an APS-C body, the K-1 gives me a similar step up in ISO and AF S performance as I got going from the K-7 to the K-5, and at the time of the intro of the K-5, this was considered very significant. I doubt if too many here would spend much time considering between these two models if all things were equal.

As a shooter who is very satisfied with APS-C format (I shoot long tele for the most part), I look at using the "full frame" sensor more as another option that I can bring into play if I want, and it's a very significant option. I'm sure that many will see this as a stupid perspective, but it was worth it to me to become an early adopter of the K-5, and for a couple of hundred dollars more, about 6 years later, it's been very worthwhile for me to become an early adopter of the K-1.

I don't crop much to gain "reach", so the extra resolution of the K-3 has not really reflected much in the number of usable images I can get over a 15-16 MP body. Though my cameras are always set up in "burst high" for those few times I want a sequence, the slower burst rate of the K-1 is not a handicap for the way I shoot. I hold high ISO IQ and low light AF speed and accuracy as higher priorities for my shooting than these specs. Although I own competent lenses in the 28-70 and 80-200 f2.8 constant 35mm format classes, I much prefer carrying and shooting my DA* 16-50 and DA* 50-135 to get the same FOV ranges in fast zooms, and for me, extra resolution doesn't offer nearly as much advantage as the ability to go to higher ISO and get fast and accurate focus in lower light. My fast 50's serve dual duty as fast normal and short tele (portrait) in crop mode. My FA 77 Ltd gives me another portrait option with much greater resolution if I want it. If I need to go wider, then my DA 12-24 covers the 35mm frame from @ 18 - 24mm and that's wide enough for me in a rectilinear lens. I also have a DA 10-17 FE to play with wide.

I look at a new body and ask if this one will expand my ability to capture images that I want. A lot of the esoteric arguments for the larger format (thinner DOF, higher ultimate res, using legacy lenses "as they were designed", etc) aren't very relevant for me. I realize that I don't look at this from the same perspective as most will, but it certainly is working for me.

Scott
Forum: Pentax K-1 05-30-2016, 04:10 PM  
Likes and Dislikes of the K-1
Posted By snostorm
Replies: 66
Views: 5,810
I am primarily a bird shooter and use this to go back and forth between crop and FF quite a few times per session. I shoot with a 510mm lens combo that focuses to 6 ft and being able to go from crop to FF allows me to "step back" a few feet without having to move if a bird moves to a closer branch. This is one of the first things I tried, and is almost my default function for this wheel so far.

Scott
Forum: Pentax K-1 05-28-2016, 02:07 AM  
SHooting Modes
Posted By snostorm
Replies: 10
Views: 721
Hi dakight,

Is this a problem with the K1?

With mine, the body came with the rotating lock lever for the mode dial in the locked position, so I had to push the button on top to rotate the dial. It was set to AV, which is how I normally shoot, so I didn't change it. I just tried rotating the dial, and in all of the mode positions except M, the rear LCD showed AV -- except the small indicators for U1 through U5 did show. In other words, I couldn't get it to show TV, SV, or TAV, Bulb, X synch, or Program. I unlocked the lever, rotated the dial, and now all the modes showed on the LCD when the dial was rotated. I relocked the lever, and everything still worked fine. Maybe there's some contact that gets stuck in relation to the locking collar or button. Worth tryng. . .

Scott
Forum: Pentax DSLR Discussion 05-27-2016, 08:22 PM  
Shoudl I buy a K 1, K 3ii, or invest in a lens
Posted By snostorm
Replies: 117
Views: 7,329
Hi Norm,

I won't say that the K1 is the answer for birding, but after three weeks shooting in crop mode almost exclusively, with an FA* 300/4.5 + F1.7x AFA (a lens combo I've been shooting with with various bodies for over a decade, The K1 in crop mode works well for me.

This lens combo is very slow (max aperture of f7.7) and though AF has worked well with all bodies, including the DS, it really works a lot better with the latest versions of SAFOX, and it's noticeably better for me in lower light which is all too common. The K1 allows me to shoot at higher ISO, so I can choose faster shutter speeds, stop the lens down a bit, or both. The wider FOV allows me quicker acquisition of my subject in the VF, and being able to instantly change from FF to Crop mode or back gives me some framing versatility if the subject gets "too close". and I can't move back. I normally shoot at under 15 feet, so this can be more common than some might think, and the FA*+ 1.7x AFA combo will focus to @ 6 ft, so it's easily possible. AF-S is quicker to lock, with fewer or no micro adjustments while it's focusing depending on the light. For me, the quicker acquisition and more positive lock helps offset my age induced slower reaction times, and the AFA, though quick to lock critical focus, needs to be prefocused manually (as you know), so if the camera is quicker, I'm capable of getting more shots.

I would limit my K5 to ISO 1280, and only use the upper reaches if absolutely necessary. The K3, I limited to ISO 1000. With the K1, I let ISO go up to 4000-5000, but try to keep it below 2000. This extra stop is very valuable because (in addition to what I feel is better SR performance) feather detail is destroyed by very minor camera shake, and I shoot almost exclusively handheld. I'm finding that I get a significantly higher percentage of acceptable shots per shoot, and that works for me.

I have the luxury of having two of each FA* 300/4.5 and F 1.7x AFA, so I was able to shoot both a K5 and a K3 directly against the K1, and though I'm not immune to the novelty of using a new toy, I find myself grabbing the K1 when I go to shoot some birds.

I also picked up a DFA 150-450 (so it's been an expensive spring!) and it's a great lens, but over twice as heavy as my 510mm combo. It's WR and a bit faster, so it has a place, but my main birding lens kit will remain the same.

Here are a couple of shots that show some of the advantages. They may not be up to your standards, but they're pretty good, especially considering the conditions some were shot at.

Chipmunk -- note ISO is 2000 -- conditions overcast with little or no shadow

Brown Headed Cowbird -- also ISO 2000 by mistake, but it really didn't hurt the shot, and it showed me some possibilities if I need really high shutter speeds -- Both of these were with the 150-450 @ 450mm

House Finch -- ISO 500 so I could get 1/250 FA*300 + AFA

Scarlet Tanager -- ISO 400 so I could get 1/250. I used EV-1 and still blew out the red channel a bit, but I was able to stop down the lens 1 stop. FA* 300 + AFA

I'm not recommending this as the best body for birding for most people, but as a Pentaxian birder, it's working for me.

Scott
Forum: Pentax DSLR Discussion 05-26-2016, 03:21 PM  
How many APSC shooters will truly upgrade to K1
Posted By snostorm
Replies: 347
Views: 23,719
I'm primarily a birder and had thought that there couldn't be any advantage to going with a full 35mm format. I was wrong, and that's why just relying on numbers on a spec sheet can be so misleading. I see a lot of post where people assume that the 15MP crop mode of the K1 will be essentially the same as the 16MP K5II, and that just doesn't take into account advancements in sensors and the in-camera processing engine. For my purposes, the K1 in crop mode is almost as big a step forward from the K5II/K3 in high ISO performance as was the K5 from the K7. AF-S is noticeably quicker and more positive to lock focus, the center focus point seems to be a bit smaller and more discreet, and fine focus lock seems to be more consistent. This includes performance at lower light levels -- faster and more accurated. Add the wider FOV in the VF which helps me acquire my subject faster with ultra and super tele lenses, this is simply a better body for what I do. Being able to quickly change from 35mm to APS-C has also helped in a few instances where I was actually too close. I shoot with primes primarily, so being able to "step back" without actually moving has improved my ability to get the whole bird in frame in such instances.

I also have a Sony A7S for indoor candids without flash. The K1 is proving to be close enough in performance at ridiculously high ISO (12800 and up) that I can use it in most cases where I'd normally use the A7S. Since I already had a good Tamron 28-75/2.8, I can use the K1 for these situations unless I want completely silent operation, and that's really the main reason why I plan on keeping the Sony. The K1's shutter is pretty inconspicuous though, but the Sony can be shot totally silent. I've also found that my DA 12-24 covers the full frame from @ 18mm to 24mm, so if I need something wider, I have it.

I'm finding that I get a significantly higher percentage of shots with good to excellent feather detail. This is due to a number of things.

1. My main birding lens kit is an FA* 300/4.5 + F1.7x AFA, so it's slow (510mm f7.7 wide open). With significantly higher ISO (about 2 stops), I have both the luxury of higher shutter speeds or being able to stop down the lens for a little more sharpness.

2. Faster subject acquisition and faster AF lock gives me a fraction of a second advantage to get a shot off, and that's even more important as age slows down my reaction time.

3. I feel that the SR is more effective, and this definitely helps because I mostly shoot handheld, and a tiny bit of camera shake just destroys fine feather detail.

4. I could be wrong, but the jpegs seem to show a bit more shadow deinition than previous sensors, so it seems that the jpeg processing in the camera has been improved a bit.

5. The files seem to be a bit more flexible in PP, even though I shoot mainly jpeg.

Bottom line, even just shooting in crop mode, the K1 is a significant step up for me, and I've upgraded bodies at almost every generation -- DS, K100DS, K10, K20, K7, K5, K5II, K3, and now K1 so I am aware of just about all of the incremental upgrades Pentax has made with their bodies.

Scott
Forum: Pentax SLR Lens Discussion 05-19-2016, 01:39 PM  
DA *300 F4 without autofocus
Posted By snostorm
Replies: 22
Views: 1,100
Personally, I'd prefer a screwdrive converted DA*300 over one with SDM because that would open up the possibility of using existing Sigma and Tamron 1.4x TCs instead of being forced to get a Pentax AW 1.4 at significantly higher cost with only relatively minor optical advantage (IMO). I rarely shoot my many 300mm lenses without a TC since I'm primarily a birder, and I've stuck with my FA* 300/4.5 for a number of reasons even though the DA*300 is slightly faster and slightly better in optical performance. I saw the downsides to the DA* that it's larger and heavier (I mostly shoot handheld) and it's only really functionally compatible with the HD AW 1.4x (which was introduced long after I'd made this decision).

I'd probably pay as much as $500 for a SDM failed DA* 300 as this is really about the minimum you'd end up paying for a lens in this class.

Scott
Forum: Pentax K-1 05-19-2016, 12:46 PM  
K-1 Shutter Button
Posted By snostorm
Replies: 18
Views: 1,396
I agree with monochrome. My first thoughts were that the shutter felt more "tuned" like a custom trigger job on a firearm. I have not found that I accidentally take multiple shots if I only want one in burst mode. This, however did happen quite often with the K5, K5II, and K3, but even then, I really didn't find this anything more than a minor annoyance.

I guess I can understand that some might consider this a detraction, but it's certainly something that is easy enough to get used to. It's just another "cup half full/half empty" esoteric point for people to nitpick about.

Scott
Forum: Pentax SLR Lens Discussion 04-10-2016, 10:12 AM  
Pentax F1.7x AF compared to HD PENTAX-DA1.4x AF
Posted By snostorm
Replies: 26
Views: 1,568
Hi Norm,

f 4.5 is probably a good estimation for the upper limit of max aperture for using the 1.7x AFA. it gives an effective max aperture of f7.7, which on paper is very slow, but my experience is that the FA* 300/4.5 + the AFA will AF effectively in everything down to moderate overcast daylight conditions -- so it's very useful for me, and this is my goto everyday birding lens combo. It's only a half stop slower than most xx-500 zooms and the size/weight advantages are significant. I'll use a 300/2.8 + 1.4x and the 1.7x AFA to get more reach (714mm f6.7). With these lens combos, I really don't want/need anything longer in a super tele prime, mainly because I shoot close for the most part -- 10-15 ft, and the longer prices usually have a minimum focus distance of 13 ft or more. I passed on a very nice deal on a rare Sigma MF 500/4.5 from Kerrick James for this very reason.

With an F5.6 lens, it takes pretty bright direct sunlight, and even then AF not very reliable, so I don't even try any more. My rule of thumb for AF with TCs with Pentax bodies is that the effective max aperture needs to be faster than f8 for AF to be anywhere close to actually useful for me.

As Pentax has evolved it's AF sensor sensitivity, the absolute limit for any AF capability has moved beyond f8, but for AF to be actually useful for me, I still consider faster than f8 as my guideline for the effective max aperture (max aperture of the lens * the magnification of the TC) for TC use with AF.

Scott
Forum: Pentax SLR Lens Discussion 04-09-2016, 10:39 AM  
Pentax F1.7x AF compared to HD PENTAX-DA1.4x AF
Posted By snostorm
Replies: 26
Views: 1,568
Having an AF mechanism of its own can also be an advantage. I use the F 1.7x AFA quite a bit with AF lenses -- because of the limited range of focus and the speed of locking focus within that range. For me, the AFA works as the most effective focus limiter I've used (much easier to use than the one on the FA* 300/2.8, for ex). I can use AF to make tiny focus adjustments for static subjects (like perching birds) without having to worry that the lens might go into a long lock to lock focus hunt. Even if it does lose fine focus and hunt, the process with the limited focus range only takes a fraction of a second, and I'm back on track.

I even use the AFA with my dedicated macro lenses so I can use AF shooting macro, which is usually thought of as impractical. The focus range with the AFA at macro distances is tiny, and even a lock to lock focus hunt only moves the focus point a few mm, if even that. The added magnification is a bonus.

Also, the AFA does convert f-stop in the camera for exif, and because it does not pass a FL from the lens, it requires that you set FL up when mounted (and holds this FL info from the last time I used the AFA), so FL to match SR is not the problem it is with a 3rd party TC. If you use a lot of different lenses with it, then you must manually change the FL for SR, if you use the same lens, it's essentially automatic.

I guess advantages/disadvantages pretty much depends on one's perspective.

Scott
Forum: Pentax DSLR Discussion 03-17-2016, 05:55 PM  
Are Teleconvertors of no use on APS-C bodies?
Posted By snostorm
Replies: 17
Views: 1,445
Hi stemked,

Personal experience tells me this proposition does not hold up. I've been shooting birds with Pentax bodies, premium ultra tele primes, and a variety of quality TCs for over 10 years. During this time, the bodies I've used have increased from 6, to 10, then 14, 16, and finally 24 MP, and my results have gotten progressively better, not worse as would be expected if this principle of more pixel density + TC use were true. I'd have expected that a 4x difference in pixel density would really show up, but I actually get consistently better detail and images with my 16 and 24 pixel bodies than I ever did with the 6 and 10 MP bodies.

But why even take my word for it. Mount one of your super teles and a TC on a sturdy tripod and take a series of shots of the same subject in good light (and a nice high shutter speed) with your K5 and K3, then pick the best from each body. If this principle is true, then the 1.5x difference in pixel density should show you consistently degraded images with the K3. If not, then believe your eyes, not some guy making what might seem like a logical argument on the internet.

Scott
Forum: Digital Processing, Software, and Printing 03-11-2016, 02:48 PM  
Compressing a photo?
Posted By snostorm
Replies: 12
Views: 803
Hi alamo5000,

I'd suggest that you look into Jpeg Mini. It's a program that was developed to give you much smaller jpeg files without much loss of IQ. You can get their free version which allows you to process up to 20 images per day, or buy their full version. With this, you can develop your RAW files, and downsize them appropriately for website display at whatever specified pixel count dimensions, convert this to lowest compression (highest quality) jpegs, then recompress them with jpeg mini to reduce the file size further to save bandwidth without sacrificing much IQ. I've recently discovered this and am impressed. When an algorithm is developed for maximum compression with the least IQ loss, some amazing things can be done.

JPEGmini - Your Photos on a Diet!

Scott
Forum: Pentax SLR Lens Discussion 03-11-2016, 11:36 AM  
Stories behind lens purchases
Posted By snostorm
Replies: 33
Views: 2,097
I have a couple of pretty good ones:

I placed a low bid (under $200 USD) on a Tamron Adaptall 2 SP 180 f2.5 LD IF that was being offered and described as having a foggy internal element. Nobody else place a bid, and I won it. When I received it, all that was wrong was the rear element was VERY dusty as the lens had probably been stored front element down with no rear cap for quite some time. After a careful cleaning, the optics turned out to be in excellent condition, so I got this excellent lens for a song.

I had been in the market for one of the Pentax 200mm f4 Macros for quite a while (a couple of years actually), but had pretty much given up on getting one for a reasonable price, decided to settle for a Sigma EX 180 f3.5 Macro just as Sigma decided to discontinue this model in K mount. The new stock at dealers had vanished quickly once the word had gotten out, but I saw an "opened box" example offered by Adorama with the full warranty for $600 USD, and jumped on it, probably the last "new" one in the US. By this time, used ones were already being offered at $1000 or more. When I received the lens, it was obvious that only the lens had been unwrapped, everything else in the box looked untouched. When I took some test shots, I was disappointed to see that most of the shots were overexposed. Taking the time to really examine the lens, I found the aperture lever had been bent inward and was rubbing on the side of the slot. Two seconds with a small needle nose repositioned the lever, and the lens now worked as it should.

I'm a big fan of the F 1.7x Auto Focusing Adapter, and use them virtually every day for birding and macro shooting. I used to search the internet for obscure used camera dealers who might offer the occasional Pentax goodie for sale. I found a listing for a 1.7x AFA from a Minnesota dealer in a small town. It was listed at $75, at a time when used ones averaged about $275, and a batch of "new" ones had appeared and were being offered for $325 and up from a dealer in Asia. I called the guy, and he confirmed the $75 price, so I gave him my CC#. I already had two of these, but couldn't pass on this one, so now I have 3, and paid an average of $125 each for them.

I've been pretty lucky in the past buying used Pentax lenses, so have gotten many that I consider really good deals, but these were probably the best.

Scott
Forum: Pentax DSLR Discussion 03-11-2016, 10:39 AM  
Poll: OK, given what we know, how many will buy a K-1?
Posted By snostorm
Replies: 124
Views: 5,761
This is pretty much where I'm at.

I chose #7 though I tend to view the purchase of a K1 as more of an addition to my photographic arsenal than an upgrade from the K3, which I'm anticipating will likely continue to be my goto body.

My K-3 works for most common situations for me (mainly long tele or macro shooting). I've added an A7S with a couple of FE lenses for low light work and situations where the EVF and/or totally silent operation are advantages, but I've had 12 years of LBA where I've added quite a few K mount lenses that work adequately with a 36x24 format body, and though they do work with the A7S with an adapter, I generally prefer an OVF, AF, and the Pentax user interface that I'm so used to. The K1 will give me more FOV versatility with lenses I already have, higher ISO capability, and I have some ideas about how shooting in the crop mode might give me some advantages, especially if the AF is as improved as some have claimed (but I've heard this all before, so I'm not holding my breath, but I am hopeful. ..).

I'll wait for the first adopters to weigh in before I buy one, but I doubt that I'll wait for any significant price drop before picking one up.

Scott
Forum: Pentax Camera and Field Accessories 11-23-2015, 05:03 PM  
Wireless Flash Question - How to Make Main Flash Not Part of Exposure?
Posted By snostorm
Replies: 26
Views: 1,987
The easiest thing to do is take some exposed/developed film leader (the black part before the first exposure) and tape it over your on-camera "master". It will block most of the visible light, but let enough IR through to trigger your off-camera flash and the P-TTL preflashes for metering. I went to my local B&M camera shop and they gave me some of these leader sections from their film developing service at no charge.

Also, there are a few IR bypass filters that clip onto the pop up flash to block the visible light, but let the IR signals through. Metz makes one and bundles it with it's wireless P-TTL macro flash, but I don't know if it can be obtained separately.

Scott
Forum: Pentax SLR Lens Discussion 11-22-2015, 02:26 PM  
It's final: Teleconverters Suck
Posted By snostorm
Replies: 49
Views: 3,415
I'll add my 2 to this thread. I haven't read all of the posts, and am not sure whether there is any tongue-in-cheek involved, but my experience with premium prime ultra-teles + TC(s) have allowed me to come to the conclusion that I don't really need more than 300mm in a premium grade lens as I get very acceptable results for my taste by adding TC(s) if I need more reach.

I have and use the following:
FA* 300/4.5
Canon FD 300/4 L converted to K mount
FA* 300/2.8
Sigma EX 300/2.8 APO
Tamron SP 300/2.8 Mod 60B Adaptall 2

Tamron F 1.4x MC4 PZ AF
Sigma EX 1.4x APO AF
Pentax F 1.7x AFA

I'll also use a Tamron SP 70-200/2.8 Adaptall 2 or a Sigma EX 100-300/4 APO DG with TCs, but no other zooms I have are suitable to use with TCs from an IQ standpoint in my experience, except for bird ID purposes.

I pretty much summed up with examples in this post : https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/234080-help...ml#post2483889

Some more in this reply: https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/235233-what...ml#post2489475

Bottom line, I'd rather carry two 300mm lenses (an f4/4.5 and an f2.8) + three TCs and Q body with adapters to get usable 300mm, 420mm, 510mm, 600mm and 714mm (and well beyond with the Q) than deal with the extra weight, size, and MUCH longer MFDs of longer lenses like the DA 560, Sigma EX 500/4.5, FA* 600/4, and FA* 250-600/5.6. Sure, there are some slight compromises in IQ, but at 65 yo, with a weak heart, it's just not in the cards for me to carry my convenient goto 300s PLUS anything longer in a super tele prime or zoom.

Of course, YMMV. . . most do :hmm:

Scott
Forum: Pentax SLR Lens Discussion 11-15-2015, 02:23 PM  
Pentax 150-450 Questions
Posted By snostorm
Replies: 6
Views: 1,150
Hi stemked,

I don't have the lens, but what you need in a plate is one that is long enough so you can balance your camera/lens combo on the head, and one with at least one slot so you can use both attachment points. There are countless sources for A/S compatible plates at this time as the mounting system is adopted by more head mfgs, so you can pretty much choose your source once you determine the length you need. My goto sources for A/S plates have been Hejnar and Sunwayfoto as they both offer pretty full lines of plates and clamps, but I've had just about everything I need for my support system for quite a few years, so I may not be aware of other good suppliers that have appeared in the meantime.

Hejnar Photo - Design Manufacture Delivered

http://www.sunwayfoto.com/e_index.aspx

Hejnar will also make custom plates to the user's specs.

I'm sure you can find bargain priced plates from a number of sources, but you just paid a premium for a pro level super tele zoom and I assume you also have a top end body. IMO it deserves a top quality plate, but YMMV. . .

Scott
Forum: Pentax Q 10-26-2015, 10:09 AM  
Turn the LCD into an EVF
Posted By snostorm
Replies: 5
Views: 1,006
Hi Denny,

This is an interesting idea, but would probably need an ultra high res LCD to be of any practical use, and the Q series cameras have pretty low res LCDs compared to what's available in other camera models. A really low res EVF as you propose might be enough for framing, but I think it would be relatively useless for MF with adapted lenses, where a true EVF would really make a difference.

Scott
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