Stitzer23: Why do the spots appear at certain f stops only? Its on the sensor after all. Appreciate any explanation please. Thanks.
You're welcome!Besides the lens aperture, another important factor for the visibility of the spots is the distance from these spots to the sensor, which is basically given by the thickness of the filter stack. The m43 cameras with filter stack of 4 mm are the less prone to show the spots on the sensor, while the digital Leicas with filter stack of only 1 mm are the most. The cameras from Nikon, Canon, Sony, Fuji, Pentax, etc, with filter stack of 2 mm are between these two extremes.
In fact, the visibility of spots is given not by the depth of field, but by the size of the umbra (darkest zone of the shadow) produced by blocking the light rays by the spots on the sensor. The size of the umbra depends on the size of the illuminating source, as shown in this figure:
In the case of a sensor in a camera, the illuminating source is the lens exit pupil, whose size is inversely proportional to the F-number. This explains why the spots on the sensor are more visible for small apertures (F11, F16, F22, etc.)
A positive point of Lomo lenses is that when someone buys a Lomo lens, he need not worry about whether it is within specifications or he got a bad sample. In practice, it is all the same.
Frank_BR: Possibly the spots are micro bubbles of gas that formed after the cameras have gone through quality control.
Or maybe it's a new type of measles that only infects digital sensors :)
Possibly the spots are micro bubbles of gas that formed after the cameras have gone through quality control.
Frank_BR: This Jurassic lens comes from the film era, when anything less than 6x6 was considered small format. Then digital photography came along...
More than five years ago, Michael Reichmann from Luminous Landscape showed that a digital camera Canon 1DS with "only" 11 MP produced a more detailed image with less noise than a 6x7 film. Today, that the digital sensors are even better than in 2009, a good m43 camera can equal or exceeds the 6x7 film format.
The m43 sensor has a crop factor of about 4x in relation to 6x7, so a modern 600mm lens adapted to a m43 camera should overcome the NASA monster of 2540mm. Besides, if you consider that a CMOS sensor has sensitivity 50 ~ 100 times higher than a 6x7 film, then it's clear why NASA discarded this monstrous lens long time ago.
Unfortunately, Ken Rockwell is not a reliable source. Maybe you should take a look at the Luminous Landscape article I quoted before but forgot to provide the link:
This Jurassic lens comes from the film era, when anything less than 6x6 was considered small format. Then digital photography came along...
Frank_BR: Besides getting $33,500 poorer, the owner of this lens will need a new and strong shelf to expose the beast in his living room. Use as a practical photographic tool? None.
It's not just me, sir. NASA also did not find use for this lens after digital photography arrived.
Besides getting $33,500 poorer, the owner of this lens will need a new and strong shelf to expose the beast in his living room. Use as a practical photographic tool? None.
Some thoughts on the Columbia University camera:
1) This is truly a camera for available light photography… provided you are on the beach and never use smaller apertures than F2.
2) The ideal is to use only lenses with apertures greater or equal than F1.
3) Not recommended for astrophotography.
4) If you are fan of the 10-stop ND filters, forget it. But maybe you can use a 0.01-stop ND filter.
5) With a self-powered flash, this camera would be even more versatile.
More than twenty years ago, in the days of, heaven forbid, video 8, Canon had a line of consumer camcorders with rotating grip. That type of grip never caught on. To err is human, to insist on the error is ... Canon.
These superzoom cameras are especially interesting for macro and super-telephoto photography. The current 1/2.3" sensors are very good, and certainly better than the sensor used in an iPhone 6, for example. The quality of the pictures produced by a 1/2.3" sensor is not spectacular like a digital FF camera, but it rivals the best 35 mm photographic films from 20 years ago. I think the superzoom cameras are unfairly undervalued.
Rich1939: 2000 mm will sell the hell out of this and the resultant atmosphere distorted images will disappoint the hell out of the buyers.
2000 mm can be very useful for shooting birds and small animals at short and medium distances, for which the effect of the atmosphere is negligible.
AlexisH: Interesting approach. Hydrophilic rather than hydrophobic.
The filter is hydrophilic because most lenses are hydrophobic. :-)
Frank_BR: Wouldn't a deep plastic hood be simpler, cheaper, more effective?
Yes, it applies if the hood is made large enough and the lens is not an ultra wide-angle.
Protecting ultra wide-angle and fisheye lenses from raindrops is an almost insoluble problem. By the way, the "Tokina solution" would probably produce vignetting with these types of lens. Besides, surely you know that the wide angle lenses are especially efficient to reveal specks of dust, dirt, scratches, etc. on the surface of the front lens or filter. Because the raindrops falling on the Tokina hydrophilic filter do not spread immediately for physical reasons, I expect that raindrops will be visible if the lens is under constant rain.
Wouldn't a deep plastic hood be simpler, cheaper, more effective?
Yes, there is some coma but of low intensity, what makes this lens a good candidate for astrophotography.
Stunning image quality. The ultra wide-angle zoom lenses definitely caught up with fixed focal length lenses.
To my eyes, the left edge is a little softer than the right. Possibly there is a small decentring, or the mounting is slightly tilted. In practice this difference in sharpness for wide open may be negligible, especially if the aperture is closed one or two stops.
Those guys seem to believe in "Build a better mousetrap, and the world will beat a path to your door".
If they really think they have a good idea, it would be much simpler to sell this idea to Leica than trying to design a camera from scratch.