Morning Star wrote:
Just realized, I didn't say so in my first message: The number of points on the star bursts depend on the number of blades on your aperture.
I just need to figure out now, why with one lens I get nine points for nine blades, with another lens I get 14 points for seven blades.
Some detective work coming up after the holidays ;)
For the technical minded the effect is called Fraunhofer diffraction. In general you get one ray line (points) for each blade of the aperture if you have a even number of blades, and 2 for each blade if you have a odd number of blades.
I using get these lines starting at about f8 to f/9.5. It may be harder to get the effect with nearly round aperture blades. People with point & shoots that do not stop down to smaller than f/4 to f/5.6 our out of luck. With film we usually used wider f stops because film was slower so to get the effects there were star filters.
Have fun taking pictures of Christmas lights to check the effect.
dsturgis
K.V.Rajasingham wrote:
Dear hogs, any of u having any experience with using the Pentax af200t flash with Nikon d7000 ? Ur experience is much appreciated please. Thank u.
You have a Pentax dedicated flash, the contacts other than the the contact in the center of the hot shoe, and the ground contacts on the hot side are different than Nikon contacts.
I think it is new enough so it has a low enough voltage to be safe for your Nikon -it is safe on Pentax DSLR. But because of the difference of contacts it probably won't work as a dedicated flash i.e set shutter speed, or have auto exposure thru the lens. I don't have one handy to check if it can be used as a old style auto exposure flash - set the lens f stop to match the flash & flash shuts off when it has seen enough light. I may work as a fixed output flash - find its guide number, estimate distance & adjust f-stop.
But it might not flash at all on top of the Nikon.
Lastly with a proper remote trigger it can be used as a off camera flash.
dsturgis
amehta wrote:
We should be a little more precise about what we are discussing, DSLRs and MILCs (mirrorless interchangeable lens cameras). DSLRs come in two sensor sizes, full frame (35mm) and APS-C. MILCs currently are available in four sensor sizes:
1. full frame, 1x (Sony A7 series)
2. APS-C, 1.5x (Sony, Fuji)
3. micro 4/3, 2x (Olympus, Panasonic)
4. 1"/CX (Nikon 1)
so one advantage is that you get some more choices for smaller cameras.
Removing the mirror has some specific advantages. Not having a mechanical device to move is good for both reliability and vibration. The camera can be thinner because it does not need to have room for the mirror to flip up. A DSLR has to be at least as thick as the height of the sensor, the MILC does not. Because there does not need to be room for the mirror, the lens mount can be closer to the sensor. This means that wide angle lenses can be designed differently, allowing them to be smaller and lighter.
DSLR lenses are designed to be mounted a certain distance from the sensor, which is larger than the distance between the MILC lens mount and the sensor. That means there is room for the MILC to add an adapter to then mount the DSLR lens. Sony A-mount lenses can be attached to the Sony MILCs this way, and Nikon FX/DX lenses can be put on a Nikon 1 camera.
Some people consider the electronic viewfinder (EVF) an advantage, while others see it as a disadvantage. Each user has to decide that for themselves.
We should be a little more precise about what we a... (
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Still more sizes for for in interchangeable lens non SLR cameras (often called mirrorless).
5. Pentax introduced the Q series with a 1/2.3" sensor.
6. Later Pentax brought out a Q series with a 1/1.7" while using the same mount.
dsturgis
blacks2 wrote:
I don't think that would be true. As far as I know he only had one printing so he couldn't change it. He must be old now too. Collectible cameras in general are falling in value as my generation is dying off. I belong to a few collectors societies and the membership is about a quarter it was 25 years ago. Take my word in a few years anybody mentioned Kodak they will ask who is Kodak. Sad but true.
The last time I saw him he didn't look that old but I have aged since too.
I have 2 of his books 6th edition dated 1987, and 11th dated 2001. I haven't seen new additions in some years.
dsturgis
prayingmantis wrote:
This is indeed a beautiful camera however a few comments are worth noting. This camera can be found on page 450 of
McKeowns Cameras 2001-2002 edition. It lists a price range of $175-$250 for collectors. I often wonder where those who compile this famous colletors book do their shopping as I would jump at the opportunity to get one for $250 in much worse condition than yours. However having said that I strongly believe that your camera is an original that was beautifully refurbished. Generally I have found that the bellows on cameras as old as yours are moderately to severely deteriorated with occasional pinholes, cracking of the material of the bellows from either dry rot if the camera lived in a very dry climate or mold and the odor that goes with that mold in a humid climate. There are camera refurbishers who pay exquisite attention to restoring very old cameras and maintaining the original color scheme and embossed look on the leatherette body coverings. The refinishing of the mahogany is the easiest part of the restoration. This bellows looks too good to be original. Having watched a great deal of Antiques Roadshow on PBS I am aware that the experts say that very old antiques are worth more if the original "patina" found on old wood or old metal is left as is. Personally, as a collector of cameras if I were offered your camera or the same model where the bellows was severely deteriorated and lots of cosmetic blemishes of the wood I would choose your camera and I would not hesitate to buy it for $500, and much more if money wasn't an issue for me.
This is indeed a beautiful camera however a few co... (
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I have heard it said that McKeown raises the price in his book of a camera if he owns one, I don't know if that is true even for rare ones. I have seen him at camera shows, selling his book, probably buying cameras if something of interest comes along and taking pictures iof rarer cameras it he doesn't buy them.
dsturgis
I have seen this type of overexpose happen with a camera with with a interchangeable lens when on lens was slow to stop down to the taking aperture after pressing the shutter such that it would not be stopped down until after the shutter fired. This seems unlikely with a fixed lens camera, also most small format point and shoots don't stop the lens down.
dsturgis
Some years ago I was in a gastroenterogolist's office the place where you go to get a colonoscopy. A old man came who said his name was Reino Aho.
He pronounced the first name as Renal like referring to Kidneys and the last name as a long A + hoe.
dsturgis
Biznaga wrote:
I found a manual on line for the light meter dated 1947 so It was my older brother's. May try to open it and see what batteries it used if I can open it. Doubt it works. Not for me anyway.
Flash looks like it took AA batteries and has cable attached. May have been mine from my ancient Pentax days when flashes were connected to shutter via cable as 60's time frame fits for me.
Don't try to open the meter, the selenium cell meters do not take batteries.
dsturgis
K.V.Rajasingham wrote:
Hello hogs! During the time exposure, if the battery power gone, what will happen. Will it damage the camera. Your valuable suggestion is very much appreciated please. Thank you.
I have had camera batteries go dead while taking pictures.
What happens in approximate order of problems.
1. The camera will not take another picture even if it was working when you pressed the shutter button.
2. It will not turn on when you go to use it.
3. I had a camera that would save a file with no pixels when the battery died.
4. Possibly the camera may save a file with only some of the picture in place or one that will not load as a picture.
I don't take you will have a problem with damaging the camera, or leaving it part way thru its operation cycle. I believe the shutter is held open by an electromagnet so no power the shutter closes, probably the same with the mirror. To clean sensors you must make the battery has enough left to keep the shutter & mirror open for the cleaning.
I don't take there is any danger to the memory card either, at least that can not e fixed with little effort.
dsturgis
I go with the link to Stack Exchange.
At a given distance from the camera the DoF depends on the Circle of Confusion used to calculate the DoF and the actual lens opening. Focal length and f stop do not enter in except to determine the actual lens opening.
Kingmapix wrote:
It always amazes me when shooting the moon with 420mm of focal length, that getting the exact focus is such a touchy issue.
One could assume that the distance to the moon is very close to the infinity mark for your long lens, but still it takes a very gentle and steady touch of your hand to manually set a good focus. It's like the DOF is paper thin.
On the other hand, getting a good focus on the moon using low power lens is very easy, ie, large DOF.
Not really. The moon is about 240000 miles, that is with in the DoF of a 420mm lens & probably a 4200mm lens. You can play around with DoF calculators to check that out. The problem you have is probably because many long lenses will focus past infinity. This may be because it is not possible to set the stop accurately at infinity and temperature changes can change the length of the lens barrel enough to make it impossible to use a factory set infinity mark.
dsturgis
The artist painted the boots wrong. Notice the felt pack boots mostly look like Sorel Caribou boots. I noticed a pair of boots that look like the boots with nylon uppers & foam inserts children wore in 1970's & 1980's. I grew up in Northern Minnesota in the 1950's & 1960's long after the days depicted in these pictures and I don't remember seeing felt pack boots.
dsturgis
Yes, but if you can't get that high take the picture any way.
Later use your photo program to do a perspective control adjustment to change trapezoid or keystone shape to a rectangle.
dsturgis
wrogers wrote:
I've never taken pinhole photographs and am wondering about their mechanics and benefits. Are there any good pinhole kits for Canon cameras, in my case a 7D?
If you want to try pinhole photography as a learning experience make your own pinhole equipment.
1. Take some stiff cardboard cut to size to fit the lens mount opening, count a hole in the center, cover that hole with aluminum foil or brass shim stock, punch a pinhole in that with a sewing needle or similar tool, tape it on the body of our camera.
Your light meter may be able to take a light reading, the exposure time may be several seconds.
2. Do the same with a camera body cap. This is all pinhole kits you can buy are.
3. Get lens extension tubes or make your own tubes to get the pinhole further from the sensor thus having a longer "focal length".
More interesting pinhole photography can be done in larger format with large format film of even photographic paper.
Than you can experiment with round cameras oat meal box, or coffee can etc.
dsturgis