Quick mtf lets you test the quality of digital images. There are quite a number of questions about wideangle lens selection and about this lens in particular. For best results with any lens whenever possible stop the lens down a bit, ive found usually even of a stop is usually enough to make a big difference in the overall sharpness of the final picture, but the more you can stop down the lens the sharper your end result will be basically you just need to find a good balance between the dof. Home gear troubleshooting your digital pointandshoot camera. Andys handy focus calibration chart recommended tools. Imatest is an excellent suite of software tools designed to test lenses and. Camera lens testing sharpness, chromatic aberration and. The basic premise of a chart like this is that when photographed at an. Nov 09, 2016 ive also received quite a few emails asking if i could provide some tips for testing lens sharpness at home, so this article was born first, though a couple of thoughts my whole testing philosophy is this i want to eliminate as many variables as i possibly can and test only one thing at a time most of the time, sharpness. After all, any lens dropped onto concrete usually has become a very expensive paper wieght. Hi, i actually have the tamron 500 sp f8 and i think its a t2 mount.
This post describes an autofocus test chart ive developed, why i think its better than others ive seen, and how to use it to test the autofocus of your camera and lens. Exposure learning software application take creative manual control of your photos canon offers an excellent and easy virtual way f. Its even funny that he actually mentions photozone. How to measure the aov angle of view of a camera lens. If the target is used at the intended distance, you wont be using anything past the 2. Glue the distance scale from this page onto a piece of poster board and trim to size. For any type of modification to the 500d or 550d, the focus tests should be made.
Oct 27, 2003 bob atkins in that article is talking about socalled lens tests that are mostly published in all sorts of magazines. Jul 04, 20 for the test shots, you can use a tool such as lensalign. Camera lens testing focus testing bob atkins photography. In the center is a checkerboard pattern which is used for focusing. It has a precise computing engine and intuitive user interface that is easy to use without special training. How to test lenses with sfrplus or esfr iso imatest. Lens adapters allow you to use old lenses on digital dslr and mirrorless cameras. Ive had several of the tamron sp adaptall macro lenses over the years and always found them good. Mirror lenses, which are also known as catdiotropic or reflective, were all the rage in the 70s, and 80s but dropped out of favour in the 90s. Robert monaghans lens resolution testing page contains links to test targets. The lens testing resolution patterns are based on those used for the nbs 1010a test chart. Bob atkins, the busy director of the nature photography pages, had a page. To test, try lens whacking the minolta on the ef and you can focus to infinity. If you really want to use your lenses i suggest that you replace the lens mount.
Dxomarks comprehensive camera lens test result database allows you to browse and select lenses for comparison based on their characteristics, brand, price, lens type, lens size, focal range and aperture. If youre still not confident in your abilities, send the camera to a qualified technician for periodic sensor cleaning. Uv filters are used to block invisible ultraviolet light, to which most photographic sensors and film are at least slightly sensitive. The dcraw raw conversion software used by imatest employs no sharpening or noise reduction and has an ideal transfer curve with a default gamma of 0. In my last article, i wrote about the fact that every copy of a given lens has some bit of sample variation. You can try to decide whether the filters were on or off. You will have to manually adjust the aperture ring of the lens and you will forget sometimes. A rectilinear lens will record straight horizontal and vertical lines as straight lines. Has anyone used this test procedure and is it valid tests for out of focus lenses and reliable will produce the same results for the same lens on different test. Reviews beyond the studio tests feature articles and videos see how we see sample galleries real world performance field test videos throwback thursday classic. But you know, as i mentioned, ive been testing lenses for years, and, as i also. Shot down a few myths about how the focus test works. Buying new lenses has meant having to buy new filters, since the lens i will be using most often has a different filter size from any ive had in the past. I would test at around,at least, 100 times the focal length of the lens for any nonmacro lens.
Autofocus fine tuning in under 5 minutes fm forums. How to measure the aov angle of view and focal length of the lens 35mmfilm equivalent 703 there are two ways to measure aov. Bob atkins, the busy director of the nature photography pages, had a page on technical optics that covers lens testing. Note that there is no mechanical activation of the aperture stopdown for the lens. Sometimes the focus point is in front of the intended subject and sometimes its behind it. I have switched from the bob atkins focus chart described in the video to a new, crosshatch target i created in ps. The easiest way to do this is to have the camera horizontal and tilt the target back by 45 degrees. For the test shots, you can use a tool such as lensalign. Popular photography has been using sqf for testing lenses for years. The main challenge is to follow directions and understand the process enough to.
Camera lens testing bob atkins photography home page. Autofocus fine tuning in under 5 minutes photography software. You can start with an image in any sort of program that you can print with. The lines in the test patterns should be well resolved down to at least the 5. The dcraw raw conversion software used by imatest employs no sharpening or. You can also select a camera to see the results for all the lenses tested on it. Its currently got the nikon f mount back on and is on an fg. The 12244 is tokinas offering in the popular superwide zoom category for apsc format digital cameras. Acutance and sqf subjective quality factor imatest.
Acutance is a relatively new measurement from the ieee camera phone image quality cpiq group. Apr 27, 2019 camera lens testing sharpness, chromatic aberration and distortion bob atkins photography stay safe and healthy. The summary of all this is we first have to check the lens at widest aperture and at least at both ends of the zoom scale and several different distances from the test target. One or the web sites showing test results generated with imatest is the photozone from germany. Sqf was used for years in the photographic industry but has remained unfamiliar to most photographers. Within the resolution patterns on each side is a siemens star pattern. Youll need three pieces sizes at least 190x175mm, 91x175mm and 260x25mm.
Discussion in darkroom equipment started by kevin kehler, oct 31, 2008. Bob atkins has an excellent introduction to mtf and sqf. You can also lay the target on the floor and shoot down on it with the camera at 45 degrees. For testing my camera after the modification, i used the procedure by bob atkins on. This new target produces much more consistent results. Using old lenses on modern dslr and mirrorless cameras with. But you can also use a ruler or a readytoprint scale, such as jeffreys autofocus test chart or as described in the focus testing article from bob atkins. If you suspect that your modern slr or slr lens has autofocus problems, you can use a chart like the one offered on this page to perform some tests. This test can be used to detect front or back focus issues with a particular lens or a camera body. Purchase or print an sfrplus or esfr iso test chart and mount it on a flat surface.
The light diary podcasts posted there reference craigs own photos on this site. With their first mass shipment coming next month, canon sent us a beta sample of the new eos 5ds to examine a bit closer. Canon digital rebel xsi 450d modification page 9 checking. A guide to testing camera lenses part 1 an introduction to lens testing and evaluation. It is very consistent though and works well to test one lens vs.
I found this excellent post below from about using manual focus lenses on canon eos bodies via this great article at photojojo. Published lens tests may be optimistic by feeding the lens tester or magazine that depends upon the manufacturers revenue the very best off the assembly line. Explore lens database dxomarks comprehensive camera lens test result database allows you to browse and select lenses for comparison based on their characteristics, brand, price, lens type, lens size, focal range and aperture. Sample test photo used to calculate aov and focal length.
He also sells a lens test kit based on a modified usaf 1951 test chart. Id suggest a look at bob atkins lens defect survey at his website. These are not detailed lens tests, more aimed at giving a feeling for what the lens is like. Below is the easiest and quickest way to test if your dslr has an autofocus issue, along with a recommendation on what to do if there is a problem. Does anyone have experience with sigma and its diffraction limit. How to test lenses with sfrplus or esfr iso software used by imatest employs no sharpening or noise reduction and has an ideal transfer curve with a default gamma. There seems to be a lot of myths and misconceptions regarding filters, so before investing any more money, i decided to do my homework. Bob atkins in that article is talking about socalled lens tests that are mostly published in all sorts of magazines.
For best results with any lens whenever possible stop the lens down a bit, ive found usually even of a stop is usually enough to make a big difference in the overall sharpness of the final picture, but the more you can stop down the lens the sharper your end result will be basically you just need to find a good balance between the dof you want, the amount of available light and the. Bokeh can be simulated in software if you have enough patience. Bob atkins has compared the tamron 500mm 8 to a canon 500 f4. You set the camera on a tripod and set the lens to the largest possible aperture. Mirrormirrora guide to choosing and using mirror lenses.
A yardstick would work as well, but the i had the t and its contrast is a little better. Sharpness tests are unlike real photos because a test does everything possible to eliminate any source of unsharpness. First lets define what lensalign and focustune are and arent. At wider apertures the resolution of the lens is limited by the optical design and quality of the lens. This old style swappable tmount cheap mirror lens is sold under a variety of brands. Its nice, too, that i can simply swap the mount and use this lens on some of my vintage slrs. Bob atkins excellent introduction to mtf and sqf is highly recommended. Compare these images using a slideshow program to be sure that they are. Reviews beyond the studio tests feature articles and videos see how we see sample galleries real world performance field test videos throwback thursday classic cameras from days past. The datacolor spyderlenscal makes this task easy and the results are precise. Mtf as a measure of lens resolution a brief introduction. Acutance and subjective quality factor sqf are measures of perceived print or display sharpness.
The new canon eos 70d is canons midrange apsc sensor dslr camera with a 20. To measure the angle of view of a camera lens take an image or video of a piece of paper and follow the. Lens testing is seen as a way to make sure you got a good one. Focus test chart edited kiamashellharbour camera club. When coupled with the focustune software, a quasistatistical evaluation is possible for both detection of frontback focus and for confirmation of proper adjustment. The mindful eye craig tanners current project, now. To use the lens testing chart you set it up at 45 degrees to the axis of the lens as shown below. It is now much easier to use and it produces more detailed information. From his answer to the same question, it seems i would need to know actual focal length of a lens to test what aperture is used.
Richard stringer, a canadian cinematographer, has developed a set of target resolution charts for use in the film industry. We have many professional tests of digital photography equipment. Using old lenses on modern dslr and mirrorless cameras. A simple guide to basic tests you can do on camera lenses to make sure they are. Lensalign is a target system which is designed to enable you to tell if your lens is focusing where it should, or if its focusing in front of or behind that point front focusing or back focusing. I tried this on my canon 300d without much success, nothing wrong with the image i just found manual focus soooooooooooo hard to.
Craig tanners light diary the photo gallery of craig tanner. The image below is from bob atkins look at the 200400 and shows. Jul 21, 2008 canons eos rebel sl3 eos 250d is the latest in the companys line of diminutive dslrs. I will be using the nikon d800e as a reference camera for this article, but any modern dslr with. Ill be testing this camera too with some of the lenses, such as this test of the photosniper 300mm. Letter paper this method is easy to do but is accurate only for rectilinear lenses, not fisheye lenses. A lot of photographers dont realize that hand holding a camera even if it or the lens has image stabilization, isnt the way to get the maximum possible sharpness. Notice there are slight differences in front backfocus with each body. This article tests several mirror lenses from different manufacturers, explains the advantages and disadvantages compared to conventional refractive.
The only use of a clear filter is to protect the front of a lens. That lens has a variable aperture, so as you zoom closer in towards 55mm your widest. Like many working photographers, our work has completely dried up in these challenging times, so ill be at home a lot. Part 5 focus accuracy check for af lenses a common complaint seen on web photo forums is that cameras andor lenses arent achieving accurate focus. The program can be downloaded for testing i did it and used it for a month for. Ball heads, test basic digital photography betterphoto big bens panorama tutorials blending for noise reduction blending tips by brian chapman blur, deconvolution methods 01 blur, deconvolution methods 02 blur, deconvolution methods 03 bob atkins tips business photo forum bw conversion by rob carr bw conversion. Introduction modulation transfer function mtf sharpness. The datacolor spyderlenscal obviously costs more than my ice cream cone box and its contents are not nearly as tasty and owners of a single lens may not be able to justify the cost of this tool. The dcraw raw conversion software used by imatest employs no sharpening or noise reduction. If you are looking for the information about digital cameras and lenses you are in a right place.
To test, try lens whacking the minolta on the ef and you can. Traditionally, lens testing has been highly tedious, best left to professionals and large publications. The blur operation closely simulates the effects of poor lens quality and misfocus. Clear filters, also known as window glass filters or optical flats, are transparent and ideally perform no filtering of incoming light. Bob atkins lens focus test method photography forums. Its important to use a distance that will enable the lens to work well for a variety of distances not just the one picked for calibration. A guide to how to test a camera lens and make sure its performing as it should. What caught my eye, highest ranking lens by price200mm2. Beware any lens test which is not a random sample, bought off the shelf, without the lens tester identifying that the lens will be tested.