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Forum: Pentax Full Frame 8 Hours Ago  
A 6 year Guarantee in the EU
Posted By photoptimist
Replies: 4
Views: 325
The six year term may not mean much given this clause in the law:

Proving that an aging camera was actually defective upon delivery seems like quite a challenge. Moreover, it seems that the consumer has to pay to prove this by getting expert testimony of the defect.
Forum: Pentax K-70 9 Hours Ago  
manual mode: EV +/- , multi-exposure composite
Posted By photoptimist
Replies: 5
Views: 239
1) EV compensation is misnamed because what it really does is to adjust the meter's reading, not the shutter/aperture/ISO exposure itself. The camera then uses the compensated meter reading either to set the exposure in any of the auto-exposure modes (P, Av, Tv, TAv, or Sv) or to display the amount of over-exposure/under-exposure in M mode. In manual mode, EV compensation does work but it does so by adjusting the over-exposure/under-exposure indications.

2) the composite exposure feature is more useful for moving or change scenes rather than for unchanging ones. The HDR modes and bracketing modes are what you can to use to create a set of images at different exposures tailored from the brighter and darker elements of the scene.
Forum: Pentax Camera and Field Accessories 10 Hours Ago  
More Polarizing Filter Questions
Posted By photoptimist
Replies: 4
Views: 253
Circular polarizers contain two filter layers. The first is a linear polarizer and the second is a quarter-wave retardation plate that shifts part of the electromagnetic wave to create a circular-polarized light.

You can stack a linear polarizer in front of a circular polarizer to create a variable ND but the reverse stack won't work. You can also reverse a circular polarizer and stack it on the front of another linear or circular polarizer to create a variable ND.
Forum: Pentax SLR Lens Discussion 22 Hours Ago  
What's your favourite vintage / film-era manual focus lens, and why?
Posted By photoptimist
Replies: 44
Views: 1,048
The Pentax K 28/3.5 Shift lens is my favorite for five reasons:

1) it provides a real challenge in metering & operations;
2) it's fun to muck about with changing the perspective;
3) the 28mm focal length is quite useful on the K-1;
4) it's a damn sharp lens unshifted;
5) it's built like a tank.
Forum: General Photography 1 Day Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
Speaking of which, the iPhone also "killed" Big Phone. Nokia, Motorola, and Blackberry are all faint shells of their former glorious selves.
Forum: General Photography 2 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
The Flickr app was not preinstalled on any of the 3 iPhones or 4 iPads that we've gotten over the years.

Also note that a 2015 analysis of uploads at 500px had iPhones in 3 of the top 5 slots, too.
Forum: Pentax Q 2 Days Ago  
Pentax Q with long lens vs modern bridge camera?
Posted By photoptimist
Replies: 12
Views: 363
Nice image! ( But it is upside down! ;) )
Forum: General Photography 2 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
Indeed! And given that a picture is worth a thousand words, it's a popular way to send a message. Facebook sees about 110 billion image uploads per year.
Forum: General Photography 2 Days Ago  
Anyone experience any difficulties getting through Airport Security with camera gear?
Posted By photoptimist
Replies: 22
Views: 668
Don't sweat it. I've been through a number of airports in foreign countries with these kinds of rules. At worst, it's an inconvenient 30-seconds to put stuff in the bin and repack it at the other end.

If you are worried about theft (although with all the security surveillance at these check points, theft can't be too common), then let your wife go through first. Once she's been screened and is on the other side of the x-ray machine, then send all the camera stuff through.
Forum: General Photography 3 Days Ago  
From the Vintage Camera Collectors Facebook group yesterday
Posted By photoptimist
Replies: 3
Views: 361
One assumes their cameras only use troll film.
Forum: General Photography 4 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
^^^^^^^THIS!

The smartphone has not made the photography glass half empty. It's made the glass overflow with effervescent ideas and creativity like one of those mentos-in-a-soda-bottle fountains. All that imagery, so easily found can be inspiring. And the internet enables places like PF where it's so easy to connect to like-minded people and get answers to questions.

And then there's all the spill-over technology on the sensor front. The opportunity to sell a tens or hundreds of millions of sensors for the next generation of smartphones funds a lot R&D. The new ideas needed to make a tiny sensor produce an acceptable snapshot then feed into making big sensors with awesome DR and IQ. And the threat of smartphones pushes the traditional camera makers to up their game and provide better bodies and lenses.
Forum: General Photography 4 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
What Nokia (and Nikon, Canon, Sony, etc.) failed to understand was that taking a great picture isn't the hard part or even the most important part. The more important part is being able to do something with that picture like share it and do lots of other things with the phone/device.

Nokia did not understand the importance of third-party apps (Apple almost failed, too).

Apple may only have 20% marketshare but the people that buy iPhones use them much more intensively (more pictures, more apps, more spending, more time, etc.) than the average Android user. As normhead alluded to, the iPhone versus Android is like Pentax versus Sony in offering superior ergonomics that make Apple and Pentax more usable.
Forum: Pentax DSLR Discussion 4 Days Ago  
Photo Megabytes - Autofocus - Manual Focus
Posted By photoptimist
Replies: 25
Views: 733
Notice that the first image shows very little of the complex background and what is shown is very out of focus.

The second image shows a lot more background detail and that detail is more in focus, especially those high-contrast backlit leaves at the top of the frame.
Forum: General Talk 4 Days Ago  
Your latest acquisition
Posted By photoptimist
Replies: 13,138
Views: 891,706
Nice!

And nice surprise bonus card. I always check the card slot on garage sale cameras. Even the small cards have some value -- every camera bag I own now has a 1, 2, or 4 GB "emergency backup card" rattling around inside it.
Forum: General Photography 4 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
Great question!

Whatever kills the smartphone is going to need some way of inputting instructions -- Amazon's Echo/Alexa would sure love to replace the iPhone.

But whatever kills the smartphone is also going to need a visual interface. A smartspeaker seems like too limited an output device.

There are lots of people that like the idea of direct input to the eyes but Google Glasses didn't exactly take over the world.
Forum: General Photography 4 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
Quite true.

And digital music killed record stores.

And digital video killed video rental stores.
Forum: General Photography 4 Days Ago  
10 Years On: How the iPhone Killed Big Camera
Posted By photoptimist
Replies: 129
Views: 2,094
Indeed!

And remember when people had to buy a Sony Walkman for portable music?

And remember when people had to buy a pager to get instant messages?

And remember when people had to buy wrist watches to know what time it was?

The mobile phone and then the smartphone really killed a lot of devices.
Forum: Troubleshooting and Beginner Help 5 Days Ago  
How to prevent this pattern when taking dimly lit photos?
Posted By photoptimist
Replies: 9
Views: 503
That is quite possible. Some high-efficiency fluorescent lights and LED light use much higher frequencies that the powerline frequency. With a very short shutter speed, the scan of the mechanical shutter slit occurs over more than one cycle.
Forum: General Talk 5 Days Ago  
Autonomous vehicles
Posted By photoptimist
Replies: 274
Views: 3,777
Well, some of your neighbors do need a car at night. Some are going out for a night on the town. Some work the night shift. Some need to do some shopping. Some are going to their child's school play or baseball game. Some or going over to a friends house for dinner.

But you are quite right that the intensity of car use does drop at night. That makes night a great time for refueling/recharging, cleaning, and maintenance. And, yes, many of those autonomous cars will sit parked someplace although the amount of required parking for autonomous cars will be a fraction of the required parking for dumb cars in which every household must have at least one car that requires one parking spot for the entire night.

Cars may well go back to the city empty if the expected demand for cars in the city is high. Overall, autonomous vehicles will mean an increase in vehicle miles travelled but a decrease in the total number of vehicles and a decrease in the required number of parking spots.

Notice that with current dumb cars, every household with a car needs more than TWO parking spaces: one at home for the night, one at work during the day, and some shared fractions of a parking space at various retailers, restaurants, friends houses, stadiums, etc. A suburb of 40,000 people that currently requires 40,000 cars and over 80,000 parking spots might need less than 20,000 cars and less than 10,000 parking spots.

The more people who use autonomous vehicles for door-to-door rides, the more that shopping malls and stadiums can sell off their parking lots to build more retail shops or condos.

Tesla is not an autonomous vehicle. It is only a driver assistance system. Calling Tesla's system "autopilot" seems like a dangerous fraud to me. Most Tesla crashes are human error due to driver inattention although some would rightly argue that Tesla's driver assistance system is unsafe by design. Uber's system most certainly did see that pedestrian a full 6 seconds before impact but the vehicle was configured to only record that sensor data and not act on it. Uber's crash also happened because the human driver (and possibly Uber management) was negligent.

Technically, autonomous vehicles won't need to rely of brake lights at all. Panic stopping is only a problem for human drivers because the human visual system sucks at judging relative velocity at distance. Radar uses both the Doppler effect to directly measure both relative velocity and the range to the object to instantly see if vehicle in front of them is slowing, braking, or braking hard.

As for turn signals, autonomous vehicle can use them to communicate but they won't assume they are 100% accurate. The funny part is that as the number of autonomous vehicles on the road goes up, human drivers are going to find that they must use turn signals to change lanes. Video of unsignalled lane changes will be uploaded to the police.


How do human drivers get information about a wreck, weather related incidents, avalanches, closed roads, road work or local disaster? Or do human drivers sit by the side of the road if they can't get that information? Both humans and autonomous vehicles can benefit from mobile communications and GPS but neither requires these technologies to get places.

The rant is well deserved! I go to Boston about once a month where I have clients and friends. And my sister lives in the SF bay area. They rightly rant just like you do about parking, transit, costs, etc. Cities like Seattle, Boston, and SF are a mess which is why you could not pay me enough to live in them.
Forum: General Talk 5 Days Ago  
Autonomous vehicles
Posted By photoptimist
Replies: 274
Views: 3,777
It's still happening. Biodiesel production in the US ran at about 2.6 billion gallons in 2017 with about 72% coming from seed oils (soy, corn, and canola) and the rest coming from animal fat and recycled cooking oil.

There's also people building factories to convert sawmill waste into jetfuel with contracts to sell it to FedEx, Southwest Airlines, and others.

The level of interest in this stuff in each country varies with oil prices, the country's political climate, and the public's interest in "green" products.
Forum: General Talk 5 Days Ago  
Autonomous vehicles
Posted By photoptimist
Replies: 274
Views: 3,777
That's only a constraint if the exact same car must pickup the exact same people every day. Uber, Lyft, and every cab company does just fine with people living all over the place and changing jobs and residences. Uber even offers a car pool option that might pick up other people along the way. Each time you use it, it will be different people going different places but because Uber knows the pick-up and destination location of every rider, it can match riders going in the same general direction. Uber's carpooling it totally voluntary but it is cheaper.

As for your hopes it does not come to this, I doubt it will ever be mandatory. But it will be sought by those who don't want the expense and hassle of buying car, maintaining a car, paying insurance on a car, etc. And it will be sought by people who would rather watch a movie or catch up on email during the commute. And it will likely be much more affordable that owning a car and paying for parking in dense cities.
Forum: General Talk 5 Days Ago  
Autonomous vehicles
Posted By photoptimist
Replies: 274
Views: 3,777
So you have 40,000 people with 40,000 cars but never all 40,000 arriving at the same time. Some people are leaving as others are arriving.

In fact, all the people getting off the night shift can probably ride in all the cars that just delivered the day shift. And when those cars drop off the night shift folk, then can pick up the 20,000 workers for the next factory down the road that has it's shifts at a different time or maybe take 20,000 office workers who don't start till 8AM. Then the cars can pick up several thousand fast food workers who get to work at 10AM for the lunch rush, then ferry the factory workers to and from the food places, etc. A single car might drive 24 hours a day taking workers from different shifts and different factories to and from work, lunch, etc.

There's still more than 60,000 people riding alone in each car but maybe only 20,000 cars in the total fleet. And the icing on the cake is that no one has to compete for parking spots any more. Everyone now gets dropped off and picked-up right at the door. There's no more driving around the parking lot looking for a space or walking across the parking lot in the ran and cold.
Forum: Pentax News and Rumors 5 Days Ago  
D-FA* 85mm f1.4 also coming
Posted By photoptimist
Replies: 1,584
Views: 133,605
Today's supply chains are much more complex than the old "everything made in one place" model. There's a recent story about the crankshaft of the BMW Mini. It is first cast in France, then machined in the UK, then put in the engine in Germany, and then assembled in the car back in different place in the UK.

For Pentax lenses, production of glass blanks might be done by multiple suppliers (specialized by material). Grinding and polishing the lenses might be some place else. Coatings might be applied at a third factory. Subassembly of some element groups might be done in fourth place (if it requires special cements). And final mechanical assembly could be in fifth place. Manufacturing has become so specialized that few facilities can do it all. High-value products like lenses justify a lot of shipping to do each step where it can be most effectively done.
Forum: General Talk 5 Days Ago  
Autonomous vehicles
Posted By photoptimist
Replies: 274
Views: 3,777
Yes, peak time determines the number of vehicles required in the total fleet. But it's never all of the people once because some people work different shifts. And even the people working the usual day-time office work vary in their schedule. Some people want to be at work by 7 AM, some at 8 AM, some at 9 AM, etc. And some people are flexible -- they'd willingly leave a bit early or a bit late if it meant a better or cheaper commute.

Pick any minute of the day and there will be tons of parked cars somewhere -- the cars of the early birds will already be at the office and the cars of late risers will still be sitting in the garage. The average commuting time in the US is a bit below 30 minutes but "rush hour" seems to be two hours or more in many cities. That suggests that even if everyone has a commute during rush hour, that at most only 25% of the cars are needed to handle the peak. Put another way, a single car could provide up to four 30 minute commutes in the two hour period or more if some people commute before or after the official rush hour peak period.
Forum: Troubleshooting and Beginner Help 5 Days Ago  
How to prevent this pattern when taking dimly lit photos?
Posted By photoptimist
Replies: 9
Views: 503
Don't use an electronic shutter unless the shutter speed is a multiple of the line voltage frequency in your area (usually either 60 Hz or 50 Hz)

Using the mechanical shutter will avoid the banding although there may be slight exposure and color-shift issues with faster shutter speeds.
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