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Forum: Pentax SLR Lens Discussion
08-02-2020, 09:04 AM
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Forum: Film SLRs and Compact Film Cameras
12-15-2016, 01:24 AM
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Well, i give a try to clean the sensor with alcohol.
The blue one on the bottom ofthe following picture.
And... it's definitely better. :)
Not perfect but decent for a film camera.
I may try a better clean to achieve a perfect focus.
Thanks, you rules ! :cool:
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Forum: Pentax SLR Lens Discussion
01-28-2016, 04:30 PM
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Forum: Pentax SLR Lens Discussion
05-15-2015, 10:35 PM
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I would agree with the opinion that claiming the f/1.9 aperture was likely a marketing ploy for Pentax. It`s something that was often done in the past and actual measured aperture may be less. Some variability would occur from manufacturing tolerances too and It may very well be really f/2 or so. A reasonable sampling of the lenses would have to be carefully tested out to check on this . Likewise, many times the measured focal length of lenses can be off as much as 5%. A telephoto often measured less focal length and a wide angle more.
I`m not sure if anyone has a need to meter so carefully anymore that they would notice something in the range of 1/4 stop or less.
So practically speaking there is no real difference between f/1.9 and f/2 for the modern DSLR user.
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Forum: Canon, Nikon, Sony, and Other Camera Brands
03-23-2015, 06:22 PM
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i suspect that people will make up their own minds about your complete lack of experience with the laea4, vs. an experienced shooter like Michael Reichmann :)
YOU posted the link to the phillip reeve review, not me.
now you are suddenly whining about the validity of your own reference? LMAO
his portfolio speaks for itself, and so does yours.
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Forum: Pentax SLR Lens Discussion
03-10-2015, 08:15 AM
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I found this interesting article by Mike Johnston (known mostly for his The Online Photographer blog), at the Luminous Landscape site:
My Favorite Lens - Luminous Landscape
It is interesting that he says that the design of the join in the glued 4th and 5th elements, influences bokeh and sharpness at infinity. He says (and I don't know how correct he would be) that the 50 1.4 concave/convex surfaces yield a much better bokeh than the flat surfaces used in the Pentax 50 1.7 designs, but that the flat surfaces make the lens a bit sharper at infinity. All in all, an interesting read, especially his observation that Takumars are the smoothest focusing lenses ever made - Leica not excepted.
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Forum: Pentax SLR Lens Discussion
03-07-2015, 07:50 AM
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This is what I've learned over the years - actual professionals who've been active since the 60's might amplify this summary.
The general historical explanation of the difference in design goals between the 55/1.8's and 50/1.7's, and the 50/1.4's, related to their different intended purposes.
As a general rule the 50/1.4's were thought to be designed intentionally with softer edges and a sharp center area in order to create a pleasing 3D effect for a centered subject. That was a desirable artistic, aesthetically preferable goal in the 60's - subjectively, a 'good' subject image.
The 55/1.8's and 50/1.7's were designed for 'flat work' or 'copy work', i.e. they were intentionally designed to be uniformly sharp corner to corner. At the time the printing industry required an actual photographic negative of a 'paste up' from a typesetting machine. A camera was mounted to a Copipod or camera stand (a device to hold a camera precisely vertical) so a flat sheet could be photographed on a photo table. A printing plate was made from the negative and mounted to the printing drum, etc. There was specialized equipment for this, but an SLR and accessories with a 'flat' lens could be used in small print shops.
Apparently, 1.7's and especially f/2.0's were marketed as 'consumer' lenses and often included as a kit lens - partially to allow increased margins on the less common 50/1.4's. A 50/2.0 of course starts nearer the naturally sharper part of the aperture range, so . . . . .
Today, with digital image viewing, our aesthetic tastes have evolved to value images that are sharp across the frame. When we compare legacy 1.2's and 1.4's to legacy 1.7's and 1.8's we are expressing our current aesthetics and forgetting the original design goals.
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Forum: Canon, Nikon, Sony, and Other Camera Brands
01-28-2015, 11:40 AM
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Indeed. Thankfully consumer computer technology is managing to keep up with the camera megapixel race.
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Forum: Site Suggestions and Help
11-17-2014, 01:51 PM
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I agree with the OP. Opening a link in a new browser window is bad user interface. It 'breaks' the back button.
A new browser window is an option that is best left to the site visitor. I prefer to make that decision myself. If I'm on a page that is a list of links to other pages and I know I will want to follow a number of them, I can exercise my option by right-clicking a link and selecting 'open in a new window/tab'. I do it frequently on this site. It's a great way to read a newspaper site..
I can understand that someone who likes this behaviour would find it convenient to have new windows auto-open when clicking a link, but I find it annoying.
The default behaviour in all web browsers is to open links in the same window. A web site that breaks that behaviour is bad UI. It's my computer--I want to be in charge of how the software on my computer behaves. Inconsistent behaviour depending on what site you visit is bad UI. There's a reason target="blank" was deprecated years ago.
from Top 10 Mistakes in Web Design |
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Forum: Troubleshooting and Beginner Help
06-23-2014, 09:15 PM
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Under some conditions smoke particles will preferentially scatter polarized light, so occasionally a polarizing filter is indeed helpful. Here's a nerdy paper that discusses using this property to measure smoke particle size:
http://fire.nist.gov/bfrlpubs/fire03/PDF/f03058.pdf |
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Forum: Pentax Price Watch
06-17-2014, 10:30 AM
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I looked it up, it's darn near 15 pounds. But those who have them love them.
This winter an FF guy was shooting an FF Nikon with a 600 F4. I was shooting my k-3 with A-400 5.6. He asked what I was shooting and I said 5.6. He said, "I don't shoot 5.6." With this lens I could have said "I only shoot 2.8"... bragging rights are at stake. If you think about it, $4000 is pretty cheap for bragging rights... especially since he probably paid $12000 for his 600mm ƒ4. Really, it's cheap.
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Forum: Pentax SLR Lens Discussion
05-14-2014, 10:38 AM
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Fast glasses are expensive, even in "dead" mounts like the Canon FD.
Before the release of good 4/3 cameras they were cheaper. Now you can adapt them to many cameras with a simple, very cheap, adapter ring.
There are so many wonderful optical designs in Canon FD, Olympus OM, Konica, Minolta MD. Then some really nice movie zooms and primes in C and D mounts...
I'm happy they're getting a new lease of life. It made me sad to see them relegated to film cameras, or just collector's items.
A 135mm with max aperture of f/1.8 or f/2 is VERY fast. Wide-open soft-ish rendition was a forced design choice, without ED glasses it's quite complicate to have a razor sharp tele at max aperture.
Probably 400 USD for the Canon f/2 isn't exactly cheap, but you must remember that prices are a RELATIVE, not an ABSOLUTE value.
I have seen Porst 135mm f/1.8 lenses being sold for at least two thirds that money, and it's just a Tomioka made lens with no special allure, which just happens to be usable (WITH SR) with modern Pentax DSLR bodies. Super fast lenses allow to take a kind of pictures which can't be shot with slower objectives. Period.
I did my one and only crazy purchase, buying a super fast prime. After waiting forever for a decently priced Pentax-A 50mm f/1.2, i gave up all of a sudden, and purchased a Revuenon 50mm f/1.2 (which doesn't even have electric contacts!.. something i promised i'd never do again ;) ), spending 250 euros + shipment! It's just a fast-but-no-frills lens, originally manufactured by Cosina.
Amateurs (and often even professionals) spend good money in special tools, whatever the field of their interests.
Resolution/contrast wide open, size/bulk, and price vs performance are NOT the only ways to define the value, and the worthiness, of a lens.
Fast lenses allow to take shots which can't be made with a slower lens, just because they are... faster! :)
Hence they allow for selective focusing, with reduced depth of focus. Often they also offer a kind of "optical signature", which can't be faked either.
Many fast lenses made in the sixties/seventies were designed that way, with slightly under-corrected spherical aberration.
You can't compare crash resistance between a Ferrari and a pickup.
Simply the Ferrari was made with other qualities in mind, and people who spend crazy money for a Ferrari know all too well about that :)
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Forum: Pentax SLR Lens Discussion
05-09-2014, 03:09 PM
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+1 for Just1More Dave. 43812 is the late (5 element?) version. 43802 has 4 elements. However, I suggest you test the lens before buying. In tests I ran, both the Vivitar M42 Komine 135 f2.8 (early 5 element - 8 blades) came out better than either Taks (unfortunately), and the 135mm f3.5 smct - stopped down a bit - matched them.
IMO, both 135 f2.5 are overrated.
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Forum: Pentax SLR Lens Discussion
05-09-2014, 09:11 PM
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43801 is the Super-Takumar and has 6 aperture blades and 5 elements. The distance scale says 30 15 10 7 in meters, 100 50 30 in feet.
43812 is Super-Multi-Coated, 8 blades, 6 elements. The distance scale says 35 15 10 7 in meters, 100 40 25 in feet.
The 43802 is supposed to be the same optical formula as 43801, so probably the distance scale on that one is the same as 43801.
I remember weighing these before selling, and the weights never quite matched the numbers I found on the internet. They would be close enough.
The Super-Takumar coating will look yellow-gold on the front and purple off the rear. That was easy to capture in my photos. Super-Multi-Coating looks a lot different, very similar to an M or K lens.
Someone could probably fake the good versions by swapping distance scales and the A-M switch, add some weight inside. I bought a parts-swapped Takumar 35mm f2 once. In retrospect not a great fake, but I didn't know until someone told me.
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Forum: Pentax SLR Lens Discussion
04-20-2014, 12:01 PM
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Hey Dave, welcome.
As one who now primarily shoots Canon after mostly shooting Pentax for many years prior, my advice to you is generally that Pentax prime lenses are a lot better than most of the Pentax zooms. You will not find the consistency of excellent quality zooms that Canon offers when choosing from the Pentax line. One exception is the DA* 50-135mm. When I picked up a 7D I immediately found the Tokina version of this lens and still enjoy its quality and flexibility. That said, it's still not quite as good as your old 70-200 f4 L, which is considered one of the best zooms ever made. On the Pentax side, I preferred the Tamron 17-50mm over the similar Pentax/Tokina offerings. I used the Tamron and DA* 50-135mm to cover corporate events for years, so it's good for people and happenings.
But the Pentax limited lenses you are considering are really excellent and a core Pentax differentiator. What works for you is a matter of personal requirements and context.
M
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Forum: Pentax SLR Lens Discussion
04-20-2014, 02:19 AM
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Lots of red herrings here.
The A35-105 is not the easiest lens to focus, the focus ring throw is a bit short, especially at the 105mm end. The lens is parfocal (focus does not change with zoom) at the normal setting but becomes varifocal (focus changes with focal length) at the macro setting.
First of all check that you can actually focus at infinity by using liveview. Don't worry if the infinity focus does not actually coincide with the infinity mark. If it can't, then set it at the infinity stop and take a shot of a road, pavement etc and see where it actually focuses. If it can't reach infinity then it was either taken to bits and not reassembled correctly at some point or the infinity stop needs moving. From what I remember it can be set in three positions simply by moving screwed-in tabs accessible under the rubber grip.
Next, check that focus does not vary with zoom (except when in macro). It is a known problem with this lens that the internal nylon bushes which guide the various bits wear and loosen. The effect is that focus will change with zoom in a strange 'backlash' like fashion. Not easy to fix without major disassembly.
I think that this lens is greatly over-rated.
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Forum: Pentax Price Watch
04-13-2014, 03:44 AM
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Forum: Pentax SLR Lens Discussion
03-21-2014, 06:48 AM
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Those are some good images in the DA Limited Zoom Club... so I'm not going to try and say it's a bad lens.... it's not.... but for me, it's a lens I can live without. Because I already have so many lenses covering that range. I think a lot of people don't need lenses in this focal length, it's been covered so many times. So when a new lens comes out, they're looking to be wowed. Like the Sigma 18-35 1.8. They want something they haven't seen before. If yu don't have lenses covering that range, i.e.. you're just starting out...maybe this is a lens you might want to look at as a compliment to your 18-55. So far, I have 2 18-55s, my 18-135, a Tamron 17-50, a 21 ltd, a DA 35 2.4 and a 40 xs. How many lenses do you need in the 20-40 focal length?
That for me is the cause of the disappointment. The Sigma 18-35 offers an ƒ1.8 fixed aperture, something I don't have in any other lens in that range... that's the kind of gimmickry it takes to get noticed these days. What does the 20-40 have that other lenses don't? Maybe it's a sleeper, maybe it's going to sneak up on us...maybe it's got characteristics that aren't obvious. But any lens released in that focal length is going to have some tough sledding to get a name for itself.
The question is not whether or not you can take great pictures with it. I expect to be able to do that with any $1000 lens. The question is, what of the lenses I currently have in my bag would I leave home for it? The 18-135 is still going to be the lens on my camera most of the time because of it's range, WR and excellent performance in the ranges around 24mm, that range extends both sides of 24mm, by the way, it isn't confined to just 24mm. So, this lens I think has a chance to make an impact with new shooters. I'm not sure it's ever going to be relevant to us old timers that already carry more lenses than we want to, and have more lenses we'd like to bring on every outing but can't carry everything we'd like to bring.
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Forum: Pentax SLR Lens Discussion
03-12-2014, 03:12 PM
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The Samyang/Rokinon/Vivitar 85mm F1.4 is the way to go. Premium glass at a bargain price :)
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Forum: Pentax SLR Lens Discussion
03-07-2014, 06:06 PM
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OMG! I just got this sweet new zoom lens! It's a SMC Pentax DA 18-135mm F3.5-5.6ED AL [IF] DC WR.
As soon as I pulled it out of the box, I just KNEW this thing was retina-slicing sharp. And it turned out to be true! Like a prime lens at every focal length, it's amazing (I know because I saw a picture from a prime lens posted on this forum last week)! The bokeh is oh-so-perfect and flawless, and the colour rendition... it's to die for. In fact, I already killed someone with it. It's THAT good!
The build quality is out of this world! All-metal construction, except for the plastic barrels, outer shell, focus ring and zoom ring. It came with an ultra-high quality front lens cap, and a pretty good rear cap. There's also a nice oddly-shaped plastic sleeve that fits around the zoom ring, I assume to protect the zoom ring during transport. How thoughtful!!! A zoom ring shield!!!
Since this lens is weather resistant, I figured I'd test it by submerging it in a large vat of diet Pepsi. It passed! But then the zoom ring became a little harder to turn. Probably just needs more breaking-in. Also, the buttons on the camera tend to stick now... typical Pentax quality control. When will they ever learn?
But that's not all! To further justify this lens' cost and convince myself and everyone else that I made a wise purchasing decision, this lens also auto focuses like greased lightning on ice, except it's completely silent! The SDM DC motor is perfection itself. There's nothing wrong with it, and never will be. Pentax clearly fixed all SDM issues. I can focus from my foot to the ceiling in less than one second flat.
After I gave myself whiplash by performing the above test repeatedly, I noticed that the lens also weighs relatively little compared to my friend's FA* 600mm F4. It's also a bit smaller than that lens, so that's a big plus. With the exception of overall sharpness, contrast and colour rendition, the image quality is EXACTLY THE SAME. I bet my friend gets real jealous when he sees this.
It's not all good and awesome, though. I did come across some problems. First and foremost, this range of focal length sucks. It's not at all what I needed. What I really needed was a 300mm F2.8 prime lens. Why isn't this lens like that? I'm deducting 2 points from its score because it's not the focal length I need. For that matter, the perfect lens would be a 10-600mm f1.2 zoom. With today's technology, this should be dead easy. But once again Pentax is behind the curve. Are you listening Pentax? Make a 10-600mm f1.2 macro lens that's weather-resistant, light as a feather, produces retina-slicing sharp pictures at all apertures, and has no aberrations or distortions whatsoever, and THEN I might start taking you seriously. Until then, Canon/Nikon/Casio will always have the upper hand!
Anyways, some samples to whet your appetite. Don't worry, I've got more coming!
My Dog
My TV (check out the bokeh!!!)
Macro Of My Dog
(I showed him one of these retina-slicing sharp pictures, that's why his eyes are bleeding)
You might need an optometrist to get your retinas un-sliced after looking at those pictures. Unfortunately, optometrists don't actually do surgery, so you'll have to live with deflated eyeballs for the rest of your life. Sorry.
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Forum: Pentax SLR Lens Discussion
02-20-2014, 07:37 PM
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My experience with 100mm and 135mm lenses are that they are one of those things that fall into a sweet spot in optical design such that most of them are good, fast and sharp.
The Takumar 135/2.5 k-mount is often considered the worst of the Pentax 135mm.
Usable of course, but the others are much better.
K135/2.5 (similar to ver2 of the S.Takumar 135/2.5 M42 )
DSC0317820140125ILCE-7 by jenkwang, on Flickr
S.Takumar 135/2.5 v1 M42
20130707-IMG_0262-50 mm-Pentax_K1 by jenkwang, on Flickr
The old lenses are MF, well built in metal and nicely damped for MF.
Beautiful rendering, colors and sharp.
The new DFA 100 macro WR has no aperture ring, and the nice thing is that it has rounded aperture blades for rounded OOF highlights.
Sharp of course.
I'd suggest getting the DFA100 macro WR, since its more convenient and no slouch against the 135mm lenses.
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Forum: Pentax DSLR Discussion
02-11-2014, 02:13 AM
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Quick update.
I continue to work on getting Debug mode activated. I think the camera checks for the presents of another file based on the original debug filename but ran through some obfuscation routines. I found the routine last night - I'll write an unobfuscator and tell you what happens.
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Forum: Pentax K-01
02-05-2014, 07:13 AM
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And here's my Stormtrooper (now at about 15k actuations), at little late to the party, but wearing its most extravagant hat. :o
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Forum: Pentax News and Rumors
10-04-2013, 10:54 PM
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Looking at the side view I see 7 things I will never use:
Popup flash button
Flash sync port
Headset jack
Mic jack
Usb port
HDMI port
DC in port
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