5
votes
Accepted
What means lens optical characteristics?
Lens makers strive to make lenses that deliver a faithful image. This has never been achieved, because all lenses suffer from aberrations (optical jargon for error). There are 7 major aberrations. To ...
- 38.5k
5
votes
What exactly "professional-grade" means in Nikon line of lenses?
One reason "professional grade" is hard to define is because it's going to get manufacturer's in trouble by setting unreasonable expectations. It's easy, for example, to say that a metal bodied lens ...
- 12.5k
4
votes
Maximum distance between the camera and a specified object when the object is still visible on the picture?
This is not a practical answer (it is not a practical question), but it is a precise answer.
Let's define "not visible". If in an image, I will offer a description of "not visible" that the object ...
- 12.8k
4
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What exactly "professional-grade" means in Nikon line of lenses?
The major manufacturers do not mark lenses as "pro" or "non pro" and they probably have a good reason for that.
There are very good professionals that use cheaper "amateur grade" equipment because ...
- 5,215
4
votes
Accepted
Cheap, unbranded 85mm f/1.8 prime lenses - are they optically any good?
The same 85/1.8 lens is sold under different names, including Neewer, Opteka, Bower, Vivitar, Lightdow, and others. You don't state what camera, mount, or purpose you want these lenses for, so they ...
- 26.8k
4
votes
Accepted
42.8mm on Nikon COOLPIX P7700 > 55mm on Canon EOS 77D?
The difference is described by the so called crop factor. The Coolpix P7700 has a much smaller sensor compared to the EOS, thus it will photograph only a smaller section at the same lens focal length. ...
- 1,081
3
votes
Cheap, unbranded 85mm f/1.8 prime lenses - are they optically any good?
Pictures on the Nikon ad show it's a Jintu, or at least a Jintu box.
Jintu say that's an 8-blade aperture. Picture shows 6. You could get one actually purporting to be a Jintu for the same price… or ...
- 23.1k
3
votes
How can these photos by Martin Schoeller have such a high quality?
Martin uses Mamiya RZ67 medium format camera for his close up portraits. He lights with 2 Kino flo 4Bank lights and a strobe for background. Negatives are drum scanned for digital editing.
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3
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How many optical aberration types are there in lenses? And what are they?
Spherical Aberration: Rays coming from near the axis of the lens arrive at the focal plane a form a vertex a specific distance downstream. Rays from the margins of the lens form a vertex at a ...
- 38.5k
3
votes
Maximum distance between the camera and a specified object when the object is still visible on the picture?
I will just give you a glimpse of what are you asking, so you can do your own math.
We need to take in account:
The object
1) What is the color. Diferent colours have diferent wavelengths, so this ...
- 23.2k
2
votes
Maximum distance between the camera and a specified object when the object is still visible on the picture?
Under bright sunlight conditions, a young person with 20/20 vision can resolve an object that is approximately 3000 diameters distant. A 2 meter square object has a diagonal measure of 2.8 meters. ...
- 38.5k
2
votes
Cheap, unbranded 85mm f/1.8 prime lenses - are they optically any good?
More worried by the specs:
Mount: for CANON DSLR Mount
Compatible Brand: For Nikon
Otherwise you find a "Neewer 85mm f/1,8" on Amazon at about the same price ...
- 20.2k
2
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Can my copy of this lens (Pentax DA 18-135) have problems?
Most lenses are at least a little softer wide open, and you should expect some variation across the zoom range as well. Try looking through your archive and comparing different shots taken at specific ...
- 31.7k
2
votes
Cheap, unbranded 85mm f/1.8 prime lenses - are they optically any good?
Be aware that there is current controversy about identically-looking inexpensive lenses sold under different brands, rumoured to be from the same OEM.
For example, there are some brands offering ...
- 7,172
2
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How can these photos by Martin Schoeller have such a high quality?
Martin Schoeller did an interview with Popular Photography in which he talked about his setup:
I have never taken a digital picture, except for on vacation with a snapshot camera. I still prefer ...
- 2,966
2
votes
Sigma 70-200mm f2.8 APO DG HSM Image Quality Issue
To be honest the images look to be about fine in my opinion. I dont know what level of quality you want to achieve but if your goal would be to capture the action at a sport event those images look as ...
- 1,623
2
votes
Which is the cause of Barrel and Pincushion distortion?
"d" in the single lens formula stands for distance... i.e. magnification IS dependent on distance, axial or otherwise. A simple lens with uncorrected spherical aberrations will create an ...
- 13.9k
2
votes
Accepted
Which is the cause of Barrel and Pincushion distortion?
Look at it this way: Without any aperture in front of or behind the single element lens, both distortions make it through and are superimposed upon one another. That's a major part of why an ...
- 174k
2
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How does the Leica R Telyt-R 250 mm f/4 compare to a more modern lens?
When considering lenses that are several decades old there's a lot more to consider about a specific lens' performance than the theoretical "sharpness" of the model's design. What's even ...
- 174k
1
vote
Which is the cause of Barrel and Pincushion distortion?
As you know, the camera lens projects an image of the outside world onto the surface of film / digital sensor. The size of the image of objects is intertwined with their actual size – their distance ...
- 38.5k
1
vote
Sigma 70-200mm f2.8 APO DG HSM Image Quality Issue
The lens is only half the equation when shooting sports at wide apertures. The camera body's AF system also plays a huge role. So does the way the camera and lens interact.
In both of your images ...
- 174k
1
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How does the Leica R Telyt-R 250 mm f/4 compare to a more modern lens?
There is a big trend now to use vintage lenses on digital cameras just to get that vintage look. This is especially true for digital videographers who spend a fortune converting old lenses to use on ...
- 11
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vote
What means lens optical characteristics?
It means less distortion, less color aberration, less vignetting, a bit more sharpness.
This said the smartphone-ish look of your pictures could come from the sensor or the post processing and have ...
- 20.2k
1
vote
Accepted
What is the optical problems in these test images and what causes them?
Just a crop at the center of the picture doesn't show possible problems of vignetting, additional softness on the edges, and distortion. The images aren't very well exposed either and this reduces ...
- 20.2k
1
vote
What exactly "professional-grade" means in Nikon line of lenses?
What exactly “professional-grade” means in Nikon line of lenses?
It means nothing. It means nothing because Nikon doesn't designate certain lenses as "professional grade" and other lenses as "non-...
- 174k
1
vote
Are high end rangefinder lenses better than SLR lenses? Would I notice?
I do not think the Nikon Df can really be compared against Contax G2. One is a digital camera, the other a film one. Apples and oranges...
It is true that having to accommodate the moving mirror ...
- 6,010
1
vote
Are high end rangefinder lenses better than SLR lenses? Would I notice?
Your quote basically covers it... With a DLSR, you have to be able to fit the viewing mirror (that bounces the image onto the viewfinder screen) between the lens and the sensor (or film, in old film ...
- 3,003
1
vote
Maximum distance between the camera and a specified object when the object is still visible on the picture?
If both the subject and the camera are located on Earth (or any planet), the distance to the horizon is an upper bound. As explained in the link, with the camera at 1.7 meters above the ground and ...
- 31.7k
Only top scored, non community-wiki answers of a minimum length are eligible