What is lense iq

Contrast sensitivity: establishing normative data for use in screening prospective naval pilots. Aviat Space Environ Med. Assessment of just-noticeable differences for refractive errors and spherical aberration using visual simulation. Optom Vis Sci. Contralateral comparison of blue-filtering and non-blue-filtering intraocular lenses: glare disability, heterochromatic contrast, and photostress recovery.

Change in corneal aberrations after cataract surgery with 2 types of aspherical intraocular lenses. Hill W. November ;6 11 Comparison of tilt and decentration of 1-piece and 3-piece hydrophobic acrylic intraocular lens.

Hayashi K, Hayashi, H. Comparison of the stability of 1-piece and 3-piece acrylic intraocular lenses in the lens capsule. Search for:. X Choose a speciality to view CME courses on www. End of Issue. Calculating Optimal Spherical Aberration Because spherical aberrations originate in both the cornea and the lens, surgeons should choose the right IOL for each patient based on the total aberrations of the cornea and the IOL.

Young adult eyes have a small amount of positive spherical aberration, which is a result of the combination of positive sphere in the cornea and negative sphere in the lens. But as the crystalline lens ages, its spherical aberration increases.

Instead I'll try to simplify the categories and weigh their relative importance to me : The first three points are described more fully and clearly by Michael Reichmann at Luminous Landscape. Almost all lenses transmit acceptable levels of detail for full scenes in smaller prints or for compressed-size web use, but some photographers have stricter demands on their lenses astronomers, bird photographers, and anyone who finds themselves cropping much of the image away to get a small portion of the scene.

Also known as acutance - how "acute" the difference between regions at a border appears. This is important because you want vivid scenes to appear vivid, not gray. Typical descriptions of boke are "nervous," "creamy," "distracting," and "smooth. One thing is certain, however: Boke is the most reliable tool available to photographers to add structure to an unstructured scene, as it merely sketches out, in big blobs of light, the parts of the scene you wish to isolate from the subject you hear a lot about the "subject isolation" capability of large aperture lenses.

Can't reposition your camera to line up with architectural elements, or the scene is completely chaotic and you have to emphasize a relationship or downplay the chaotic totality of the scene?

Get a wide lens and open it wide. Additionally, shooting in very low light is improved with wide aperture lenses. Almost always, photographers prefer to have lenses that do not detract attention from the elements in focus, while retaining the correct color of background elements. Some of these aberrations affect blur quality, so we are focusing on other effects. Some common problems are purple fringing sometimes I see this blamed on recent DSLR sensors and green fringes.

Some fringes are relatively easy to correct; others are more difficult. In the same vein, the ability of a lens to render straight lines as straight, without any distortion, is also important, though its cause is different.

Different types of glass, lens coatings, and lens designs minimize these effects - one of the most sought-after designs is the apochromatic lens, which is designed to ensure that different wavelengths of light focus at the same point at the image sensor no simple task actually. In some lenses, when the aperture is reduced, the area which is rendered in sharp focus changes. Since DSLRs and even mirrorless cameras generally meter and focus wide open, this presents a real problem if you focus on a subject with the lens aperture wide open for a bright viewfinder and quick AF, but it turns out that the area in focus has changed after the aperture has closed for the shot and you don't get any feedback suggesting this until you review the shot.

A couple other points: The susceptibility of the lens to flare is important, especially for wide lenses, and in that case the type and quality of the lens flare spots can be considered, just like with boke. There are a number of effects tracing their origins to the aperture inside the lens, as well - some render "sunstars" from relatively bright light sources when closed down, and the number of points changes depending on the aperture construction. The out-of-focus circles boke quality is degraded if the aperture is not round - many older lenses with straight aperture blades render polygonal blur circles.

And DO diffractive optics lenses, which operate on the same Fresnel lens principle as a lighthouse's lens, also can have unsatisfying blur quality like a bullseye and haloing - but they don't have to. Canon-F1 Guest. Sep 22, 1, 0 Canada. Simply put for me it is sharpness, details, contrast and color rendition. The last one is one of the main reason I picked Canon over Nikon Show hidden low quality content. You must log in or register to reply here. Similar threads A.

Considering RF 85mm f2 and 50 1. Act Jul 3, Lenses. See What characteristics make a digital sensor good? The Technique While IQ is usually considered without regard for artistic merit, a generally-correct exposure is usually part of it, as is a lack of blur from camera shake.

One might even consider lighting here, although that's getting to the gray edges of the definition slight pun intended. The Post-processing and the Print Once an image is captured, there's a whole 'nuther level of image quality regarding processing the image properly for rendering. For on-screen display, for example, a highly-compressed JPEG with many artifacts would be considered to have poor IQ; for a print, there are numerous factors like bad rendition of shadows, banding from a misaligned inkjet, or posterization from low-bit-depth colorspace conversion.

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Linked See more linked questions. Related Hot Network Questions. Invest Ophthalmol Vis Sci. Contralateral comparison of blue-filtering and non-blue-filtering intraocular lenses: glare disability, heterochromatic contrast, and photostress recovery. Clin Ophthalmol.

Reduced effect of glare disability on driving performance in patients with blue light-filtering intraocular lenses. Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans. J Appl Physiol. The effect of blue light exposure in an ocular melanoma animal model.

J Exp Clin Cancer Res. The effect of blue light exposure and use of intraocular lenses on human uveal melanoma cell lines. Melanoma Res. AcrySof Natural filter decreases blue light-induced apoptosis in human retinal pigment epithelium.

Use of adaptive optics to determine the optimal ocular spherical aberration. Contrast sensitivity and spherical aberration in eyes implanted with AcrySof IQ and AcrySof Natural intraocular lens: the results of a meta-analysis. PLoS One. Ocular higher order aberrations in eyes with supra-normal vision. Am J Ophthalmol. Each of these IOLs is indicated for visual correction of aphakia in adult patients following cataract surgery.

In addition, the AcrySof Toric IOLs are indicated to correct pre-existing corneal astigmatism at the time of cataract surgery. All of these IOLs are intended for placement in the capsular bag. Caution should be used prior to lens encapsulation to avoid lens decentration or dislocation. Viscoelastic should be removed from the eye at the close of surgery.