Who Killed Infinity Focus?




Not long ago, it seemed that if you wanted to focus your camera lens so everything beyond a certain distance was in focus, you would turn your focus ring to the "infinity" setting. The lens barrel had engraved or painted markings displaying distances in feet and/or meters and just past the highest digits was this symbol: ∞


One of the traditional hallmarks of a high-quality manual-focus lens was that the focus ring would stop precisely at the ∞ mark. This allowed photographers to set their lenses quickly so that everything past a known distance would be in focus. Photographers could do this on the run without looking at their lenses or doing hyper-focal calculations and adjustments. It was, and is, an especially handy feature for nighttime and astrophotographers who might be trying to focus in environments where there isn't enough light to see an image in the viewfinder.


Even some older zoom lenses were parfocal (maintained constant focus through their zoom range) and featured hard stops at the ∞ mark, along with colorful, curving hyper-focal markings.


Adding to the feel of precision, focus and zoom rings on high-quality lenses felt silky smooth and had just the right amount of friction. Using these mechanical works of art was a pleasure and life was good!


Then... autofocus was invented.


Suddenly, lenses were being designed that had focus rings that turned, as Toy Story movie hero Buzz Lightyear exclaimed, "To infinity... and beyond!" Some new lenses were made with focus rings that turned continuously without stopping. And, infuriating many traditionalists, lenses were quickly coming on the market with―gasp―absolutely no focus markings at all! Now it was all but impossible to do hyper-focal calculations, or blindly turn the lens to an infinity focus point. Also, many lenses said goodbye to the silky smooth tactile mechanical experience as autofocus motor strength required that focus rings be nearly frictionless.


Why the change?


Many photographers, writers, and bloggers have varying ideas about why and how this happened. Theories range from preserving autofocus motors, reducing manufacturing costs, and compensating for thermal expansion of metal and plastic parts and/or the lens glass itself, allowing infrared (IR) photo capabilities, and allowances for the increasing resolution of digital sensors being less forgiving than film. However, nothing I read seemed to have information gained directly from those who make and design the lenses. I wanted to know how different lens makers approach the infinity focus setting and why they do what they do, so I started contacting the companies that manufacture the lenses that B&H sells.



Above: Infinity Focus symbol on various lenses  

Above: Image of the Brooklyn Bridge


Above: Image taken at infinity focus


From a Canon Lens Owner's Manual: To compensate for shifting of the infinity focus point that results from changes in temperature. The infinity position at normal temperature is the point at which the vertical line of the L mark is aligned with the distance indicator on the distance scale.


NOTE: For accurate manual focusing of subjects at infinity, look through the viewfinder or look at the magnified image* on the LCD screen while rotating the focusing ring.



Canon's extensive lens line features some manual-focus models intermixed with their popular EF and EF-S series autofocus lenses. These manual-focus lenses feature a conventional helicoid mechanism and the classic hard stops at both the infinity mark and the minimum-focus distance setting. These manual focus lenses include the MP-E 65mm Macrophoto and the company’s tilt-shift TS-E lenses.


When it comes to Canon’s autofocus lenses, the EF and EF-S lenses feature the focusing motors inside the lens barrels, not driven by the camera body. These internal motors are designed to be lightweight and power-consumption friendly, and do not provide enough torque to drive the traditional manual-focus helicoid mechanism.


Canon utilizes two different systems for manually focusing an autofocus lens: mechanical and electronic. In both cases, the autofocus drive system is disengaged from the focus system. Canon says that, in general, it is possible to incorporate hard stops into this system, but it would add considerably to the manufacturing cost of the lens for a feature with limited benefits.


For decades, the Canon FD and EF lenses have featured a variable infinity setting. Canon has two reasons for this:

  1. Thermal expansion

  2. Allowances for infrared photography

Canon is compensating for thermal expansion in its optics, not the lens body. Optical glass and crystal materials, such as fluorite, are known to expand and contract with ambient temperature changes. These changes are not seen with the naked eye, but can cause refraction of the lens surface and, therefore, change the infinity distance. This is more of a factor in longer focal lengths but, as Canon points out, many of today's wide-angle zooms are simply inverted telephoto designs and they can be affected by temperature changes.


Have you ever wondered why Canon telephoto lenses are white? Well, when the company introduced its FC 600mm f/4.5 SSC lens in 1976, designers painted the lens barrel white to minimize thermal expansion of the fluorite lens. Nowadays, it is more of a marketing scheme than anything, but thermal compensation for infinity focus started Canon’s trademark white lens feature!



When it comes to IR photography, the longer wavelengths of IR light come into focus at a point farther than that for visible light. Due to this and certain industrial and military applications utilizing Canon lenses, the variable infinity range allows the user to maintain sharp focus, regardless of the lens's use.




The only Fujifilm lenses in the current Fujifilm lineup featuring focus-distance markings are the Fujifilm XF 14mm f/2.8 R and the Fujifilm XF 23mm f/1.4 R lenses. Both barrels feature an ∞ mark, but the user can turn the focus ring beyond it. Interestingly, on these lenses, by turning the focus ring manually, you are not physically moving the lenses inside the lens body—you are manually sending electronic instructions to the autofocus motors inside the lens, which are then changing the lens focus; there is no clutch system that disengages the autofocus system. Therefore, on these lenses, it is not necessary to have a hard-stop at the infinity point, as the lens/camera autofocus system components are handling the focus responsibilities.


Fujifilm says that because, even when "manually" focusing the lens, you are using the AF system, and the camera can figure out when the lens is focused at infinity by using a hybrid contrast and phase-detection autofocus sensor. Therefore, no special lens calibration or hard stop is needed. The virtual variable range of infinity on Fujifilm lenses allows for temperature expansion.




Some Hasselblad lenses feature an "over-focus" position, allowing the user to turn the lens past the ∞ mark. However, this distance may, in fact, be so minuscule that you cannot visually see it on the lens barrel marking. Hasselblad does this to ensure sharp focus when the lens is subject to thermal expansion.



Interestingly, Hasselblad currently features a special lens for aerial photography that is fixed at an infinity focus position and the company has been developing cameras for NASA, including the cameras and Zeiss lenses used on the moon, that are subject to a 300-degree C temperature swing between sun and shade—possibly the greatest thermal challenge in the photography world—with designated infinity settings.




Leica's lenses have always been known for their mechanical precision and great tactile feel when it comes to focus, zoom, and aperture adjustments. Today, the Leica M lenses still feature a hard stop at the ∞ mark. However, some of the company’s R-system and all of its S-system lenses allow for movement past the infinity setting. Leica claims this is for accommodating thermal action, which is more critical as the size of the digital format grows. This movement also helps compensate for a physical change in focal length when teleconverters or adapters are added to a lens setup. The Leica M lenses, with their compact size and limited focal-length ranges, do not need this additional movement.


On Mamiya lenses, users will find a hard stop at the right edge of the ∞ mark. This hard stop sits on the "far side" of a calibrated infinity position and indicates the far point of a variable infinity range. Mamiya lenses feature this variable range for the purposes of supporting its "Open Platform" philosophy as the company is designing camera bodies and lenses that accommodate digital backs from other manufacturers, some more than a decade old. Mamiya builds to exacting standards, but wants its camera system to accommodate a wide variety of backs that may not have been built to Mamiya's tolerances. For autofocus work, the 645DF+ features a system that calibrates with the autofocus of a specific lens, and matches the focal plane seen by the AF module to that of the sensor, to provide precision focusing with different backs.


Mamiya states that, within the specified working temperature range of its camera systems, there should be no differences in focusing due to thermal expansion when operating inside that range.



Mamiya's wide-angle lenses are required to produce a large image circle for medium format cameras. The company adds that most wide-angle lenses will feature some field curvature, and the ability to focus beyond infinity helps compensate for that. This is even more evident in large format photography, where many helical focusing mechanisms have user-adjustable scales.


Many of today's Nikon lenses feature focus rings that move beyond both the ∞ mark and the close-focus point because the Nikkor AF-S autofocus system features a differential cam that allows for both autofocus and autofocus with manual override. The "M/A" mode allows the photographer to manually turn the focus ring when the lens is in any autofocus mode, thus permitting manual-focus capabilities without having to change focus modes from auto to manual.



Older Nikkor AF lenses and some of the AF-S line, such as the AF-S DX 18-55mm, do not feature the M/A autofocus mode and users of those lenses will see hard stops at the ∞ mark and close-focus point (if the lens barrel has focus markings) very similar to the older, but still-in-production, Nikon manual-focus lenses.




The current Olympus line has three M.ZUIKO lenses with manual focus rings and focus markings. The M.ZUIKO 12-40mm f2.8 PRO, M.ZUIKO 12mm f2.0 PREMIUM, and M.ZUIKO 17mm f1.8 PREMIUM feature the ability for the photographer to turn the ring past the ∞ mark for three reasons:

  1. For manual-focus photography

  2. For the autofocus system

  3. For the Image Stabilization system

For manual focus, the system allows the user to definitively confirm accurate focus when focusing on distant subjects using "Magnified Assist" or "Focus Peaking." For autofocus, this ability to turn past the ∞ mark is designed to allow the Olympus contrast-detection autofocus system to function. The autofocus system is designed to focus by moving just past the determined focus point and then back to the point to ensure accurate autofocus. Imagine if you may, how you might have focused a manual-focus lens, binoculars, or telescope by going back and forth between blurry, sharp, and blurry. The Olympus AF system does the same thing. Lastly, Olympus states that with the advent of both in-camera and in-lens image stabilization (IS), it became necessary to allow lens focusing past the infinity position, as the IS system moves either the sensor or lens group, which will then change the location of the infinity focus point.


Many legacy Olympus lenses do feature a hard stop at the ∞ mark. Those using older Olympus lenses may confirm the infinity focus accuracy using their digital EM-1's focus peaking feature.


Panasonic lenses do not have a mechanical stop at the ∞ mark by design. The company admits that this may be frustrating to some photographers, but they have incorporated some high-tech methods to set their "G" series lenses to infinity focus:

  1. Select the manual focus "MF" mode on the camera, and then turn the camera off. Turn the camera back on and it will automatically reset to the infinity focus point.

  2. Using the rear LCD screen with the camera in "MF" mode, turn the focus ring on the lens until the red and white scales meet (see photo below) and you have precise infinity focus.



Grab a Pentax lens off the shelf at B&H and you will see that even the autofocus zoom lenses have a hard stop precisely at the ∞ mark. Unfortunately, I was unable to get information from their engineers; nevertheless, their owner's manuals tell a slightly different story:


From DA Interchangeable Lens Manual: “When focusing with manual focus or the Quick-Shift Focus System, the mechanism allows the focusing ring to rotate freely after it is set to the ∞ (infinity) or the minimum focus distance ends. However, do not attempt to rotate it any farther than these ends as this will result in decreased performance.”


From the Pentax-D FA Interchangeable Lens Manual: "Note: When focusing manually, do not turn the focusing ring all the way to infinity or to the minimum focusing distance."


From the smc Pentax-FA Interchangeable Lens Manual: "The telephoto lens's focusing ring stops turning at slightly past the ∞ infinity symbol. This is because, the point of focus changes depending on the temperature, and sometimes the focus is achieved beyond the ∞ symbol. Even when focusing at infinity, always look through the viewfinder to make sure the subject is in focus. When the lens is set for manual focus, the focusing ring can continue to turn even past the minimum focusing distance or infinity mark."


From the FA Interchangeable Lens Manual: "When the lens is set to the manual-focus position and the focusing ring is fully rotated to the right or left to manually focus the lens, it will keep rotating, as no stoppers are provided at the ∞ (infinity) or shortest-distance positions.


"The focusing ring of the telephoto lens stops slightly past the ∞ mark. This is because temperature change chases the focusing point to shift, making the lens focus on a point past the ∞ mark. Even when shooting at infinity, be sure the lens is in focus utilizing the focus indicator before releasing the shutter."


A relative newcomer to the interchangeable-lens camera arena, Samsung's lenses have focusing rings that turn past infinity and only one of their current line, the Samsung 85 f/1.4 ED SSA, features focusing marks on the lens. Their owner's manuals state that the zoom lenses are not parfocal and need focus adjustments after zooming in or out.


Elite Brands sells manual-focus lenses under the Rokinon/Samyang branding. Their lenses feature a hard stop following a variable infinity region designated by an "L" marking on the lens or the ∞ mark by itself. These manual-focus lenses have a superb, classic, tactile feel. Being an aftermarket manufacturer, they are designing lenses that accommodate upwards of 10 different camera mounts and, because of the varying thicknesses of these mounts, need to allow users to utilize a variable infinity focus range to find precise focus. Precisely calibrating an infinity point for each variant of the lenses for each mount would be cost prohibitive.



Schneider Optics features a very small line of manual-focus lenses for DSLR cameras. The company's classic PC-Super-Angulon lens features a hard stop at the ∞ mark, as do its newer PC-Tilt Shift lenses that come in different focal lengths and several different lens mounts. Schneider states that the PC-Tilt Shift line's infinity setting is built to a tolerance of ± 0.02 mm, so that the infinity focus will be sharp even with the lens aperture opened to its maximum. This precision extends to the focusing mechanism itself. Schneider finds that the thermal expansion of the lens can be accommodated for in the depth of field of the aperture setting, even at full aperture, and is not a factor affecting the lens's precise focus.


The company makes an extensive line of cinema lenses that feature a variable infinity range to accommodate thermal changes in the lens and for filter stacking. According to Schneider, it is not uncommon for motion picture cameras to have anywhere between two and five filters stacked on a lens. These filters may change the camera's magnification and, therefore, move the focus point―necessitating a variable infinity range.


Schneider also mentioned that the new, non-crystal glass used in optics is much more thermally and humidity stable than the older crystal "glass," and, this newer glass (sometimes referred to as low dispersion or ED glass) allows tighter manufacturing tolerances.




Some Sigma lenses feature hard stops at the ∞ mark, but their autofocus lenses with the ring-shaped Hyper Sonic Motors feature a "soft stop." The focus rings on these lenses have the ability to keep turning past both the ∞ mark and the close-focus point to protect the durability of the autofocus motor. According to the Sigma engineers in Japan, this allows the motor to slow to a stop instead of reaching the stopping point abruptly.


Sony's rapidly expanding lens line features several approaches to the infinity-focus conundrum. Many of its lenses are devoid of focus markings, and the manual focus rings spin freely with no stops at all. Several of the company’s lenses feature soft-stops and the "L" marks, denoting a variable-infinity range. The owner's manuals claim that the "infinity position provides for some adjustment to compensate for focus shift caused by a change in temperature," before recommending that focus is verified through the viewfinder or live view modes.


One of several lenses that features a hard stop at the ∞ mark is the Sony 135 f/2.8 STF lens that is unique in the Sony line—its only manual-focus lens. The lens features a classic focusing feel and sense of precision when the focus ring stops right at the ∞ mark.


From the Sony DT 50 f/1.8 SAM manual: "To shoot a subject at infinite distance in MF mode: The infinity position provides for some adjustment to compensate for focus shift caused by a change in temperature. To shoot a subject at infinite distance in MF mode, use the viewfinder and set focus.”


From the Sony DT 16-50mm f/2.8 SSM manual: "Shooting at infinity in MF: The focusing mechanism turns slightly past infinity to provide accurate focusing under various operating temperatures. Always confirm the image sharpness through the viewfinder of [sic] other viewing part, especially when the lens is focused near infinity."


From the Sony DT 11-18mm f/4.5-5.6 and 18-250mm f/3.5-6.3: "The focusing ring can be rotated slightly past the infinity to provide accurate focusing under various operating temperatures. Do not rotate the focusing ring all the way to the end when focusing manually, even at infinity. Look through the viewfinder and set the focus precisely."


All of Tamron's current zoom lenses and 90mm macro prime lens feature what they call "over infinity." This is designed into the lens to allow sharp focus at the variable infinity point, regardless of thermal expansion of the lens.


From a Tamron lens owner's manual: "The focusing ring rotates beyond the infinity position in order to properly focus to infinity under a variety of environmental conditions. When manually focusing, make sure the subject at infinity is sharp in the viewfinder."


Tokina says that, in theory, parfocal zoom lenses should be able to feature a hard stop at the ∞ mark, but the company allows its lenses to focus beyond the mark to accommodate thermal changes. The manufacturer states that even a relatively small temperature variation might cause the infinity focal point to move and, in certain situations, if a hard stop was installed, the lens may not be able to reach infinity focus.


From the Tokina 300mm f/6.3 MF Macro Manual: "Generally, a super-telephoto lens with a range of 300mm or more will have some allowance in the position of the infinitely [sic] symbol (∞). This is because the refractive index of light in air changes as the temperature in the mirror cylinder changes and the focus position may shift slightly as a result. Accordingly, be sure to adjust the focus carefully by checking the image on the finder screen, even when capturing a distant view, starry sky, or other very distant subject."


German manufacturer Voigtlander manufactures its infinity stops to high precision and spends a great deal of time manufacturing with metals and materials that combine to cancel out thermal expansion. Several Voigtlander lenses feature a hard stop at the ∞ mark and the MFT Nokton lenses have an "over infinity position."


Older Zeiss lenses for still photography feature a hard stop at the ∞ mark. Their new cinema lenses, the Master Prime, Ultra Prime, and Compact Zoom lenses will focus past infinity to provide an "extra margin of focus control." This same feature was incorporated into the new Zeiss Otus series of lenses. Zeiss states that its lenses are designed to account for thermal expansion and the variable-infinity range is not needed to compensate for changes in temperature.


Well, there you have it, directly from the sources. A combination of thermal expansion and allowances for autofocus motors seems to be the largest factor in the "softening" of the infinity focus. Thermal expansion has been around since the dawn of time, though, yet it seems to be a bigger concern to lens manufacturers now than in the past. Some makers, however, have taken measures to accommodate for thermal changes to their lenses.


I would like to thank the representatives and engineers from all of the above companies who took time out of their busy schedules to speak with me about their products. I hope you, our readers, find this information as fascinating as I have.



The best, the absolute best solution I’ve seen to this issue is on the Olympus 12mm f/2 . I see that’s one of the three lenses Olympus mentioned in reply to your original inquiry years ago. If you ask me, they were too modest about how clever their manual focus clutch is. Clutch the ring into manual focus, and a lovely (if small) distance and f-stop scale becomes visible, with a hard stop at infinity. Clutch it back to autofocus, and it performs as a modern AF lens, with focus-by-wire manual override anytime the photographer likes. I've seen no other solution be so accommodating to different shooting styles.

Hey Artie,

I don't think I have had the pleasure of the Olympus 12mm, but I will take your word for it. My FUJIFILM 14mm and 23mm lenses have the same clutch action and a hard stop that is at or very near infinity—I will have to check it tomorrow as it has been a while.

This was a not-so-common feature on a few FUJIFILM lenses.

The frustrating thing, I find, is that even old manual focus lenses like my cherished Nikon 50mm f/1.2 have to be tweaked a bit when at "infinity" on my mirrorless camera.

Thanks for reading!



Because I do a lot of night photography (northern lights/time lapse) it is a whole lot easier having the infinity mark.  I can quickly set it in the dark using a pen light since auto focus is totally useless.  You pay a lot of money for a Canon lens and you would expect Canon to include the mark for those of us who rely on it frequently.

Hi steve,

Most Canon lenses will have an infinity mark. The issue is that there is no hard stop at that mark, nor is it usually exactly at infinity! I feel your pain!...so much that I researched and wrote this article!

Thanks for reading!

Under Pentax you use a phrase "precisely at the ∞ mark". Before reading this excellent article I have been, and still am, wondering exactly where on the infinity mark is infinity? With all my old K, M, and A lenses there is a hard stop exactly in the middle of the mark, where the figure intersects. The same with an FA 100-300 zoom. Recently, trying to learn this digital business and buying 2 Pentax DSLR's, I have ended up with 3 different editions of their 18-55mm "kit" lenses, a 16-45mm lens, and a 55-300mm lens. All of them rotate to the extreme left side of the infinity mark, possibly a miniscule more. Now since these lenses have such a short throw, from one end the infinity mark to the other side can be a lot of subject distance. I see that from the right end of the mark to the next longest distance, 7 feet (!), is less than 1/8", about 3/32". From the center of the mark to 7 feet is 5/32" at most. The center of the infinity mark to where 50 feet would be is probably less than 1/16". So determining where on the infinity mark is infinity, most of the time, can be difficult and perhaps require reading glasses if not a magnifying glass. I guess that is price we must pay for autofocus lens that focus from infinity to a very short minimum distance, making focusing by scale and viewfinder not so precise and easy.

Hey Timothy,

Interesting information about the Pentax lenses. Usually the middle of the infinity mark (the intersection of the swirls) is the spot.

I haven't picked up any Pentax lenses lately, except one that definitely didn't have a hard stop, so I am unfamiliar with the kit lenses you speak of. Maybe Pentax is succumbed to the new normal. However, it is interesting that they are still having hard-stops instead of free-spinning focus rings on the lenses you mentioned.

My suggestion would be to do some start shots to test if the hard stop is accurate and the markings are not...or vice versa!

I would be curious to hear about what you discover.

Good luck and let me know if you have more questions!

Thank You For Sharing Article, I share the infinity focus blog, I think the best star trail shots are ones with something interesting framing up the focus distance then rotate your focus-ring until it's set it to the infinity mark. Get your focus right in the night. Every lens has a specific setting for achieving infinity focus. 

Thanks Todd V. for this very intuative article! I shared it in a group I administrate so other members that are having what I think is this exact issue with their types of systems they shoot with, can understand what might be the problems they are having with their focusing! I can only hope that the members that see your article in my shared post will take the time to read the entire article on B&H's site(I shared the link) so they can better understand all the information you provided! 

Thanks once again for a great read! ...
Gene Berkenbile Photography
Administrator for "Photography-The Making of Great Photographers! ..."

Thanks, Gene!

I hope this article helps your folks! Of course, wouldn't it be great if all lenses just had a hard stop at infinity? :)

Personally I would prefer they do some more careful job calibrating the lens so the infinity mark, or perhaps even with a click, works as advertised, but at the same time, still provide a little extra little room to go beyond when needed. 

Something that's precalibrated to become a deadend just makes me nervous. If there is no room left, I think I wouldn't help constantly double checking the infinities on my lens to make sure they are OK. Knowing that the room is there is more comforting.

I think, as some already mentioned above, in the old days, the tolerance of focal precision, particularly when it is for infinity was much larger, so slight errors of the infinity marks went unnoticed. These days, with everyone zooming into pixel level to check if the focus is right for every shot, the manufacturer probably figured that a hard stop for infinity is simply not feasible. I can see that would cause everyone to scream loud that their lens are broken, soon after they see even a slightest blur when shooting at infinity.


I, too wish there was precise infinity marks! When I shoot a mirrorless camera with an adapter, some lenses stay true to infinity, others seem to have a slight variance. It is frustrating!

I do miss the days (and nights) where I could just rack the camera to infinity and forget it!

Thanks for reading, YS!

“Thermal expansion has been around since the dawn of time, though, yet it seems to be a bigger concern to lens manufacturers now than in the past.”
I think, they are just an excuse for the manufactures to spend less on quality control and focus more on mass production.
I wouldn’t mind if the lenses is at a reasonable consumers price range, but if it is an expensive lens lineup, I do expect manufacture to pay more attention to all little details and the infinity mark in particular it can help a lot when shooting at night in near total darkness when camera sensor give up on focusing at anything.

I got an old Pentax prime made in Japan era, and it offers a hard stop at the ∞ mark. Very pleased to use at night. 2 of my relatively modern, FA serie is also having a hard stop at the ∞ mark. While they are not made in Japan but they are pre-digital era lens design. The same cannot be said for every digital era Pentax lens I have used or test. Sad.

Hey just a Pentax user,

I hear what you are saying. The infinity thing always bugged me...to the point that I decided to investigate it further and write this article.

There is definitely something to be said for an accurate infinity hard stop! It is sad to see that it has mostly gone away.

Thanks so much for reading!


G'day Todd,

That was a really interesting article.

I photograph auroras with a Zeiss Distagon T* 2.8/15 ZE. Do you know if this lens is focused at infinity when the focusing ring is at the hard stop?




Hey Craig,

Thanks for reading! Great lens!

I have the Zeiss Distagon T* 2.8/21 ZF.2 and it has an infinity hard stop. I would assume your 15mm does as well. The best way to check it is to test it!

But...test it during the day on something so you don't miss an amazing aurora shot!

Very interesting article! Nowadays a lot of photographers are using lens adapters to match different lensen to different camera body's. Unfortunately these adapters ALWAYS have an offset so the scaling of the lens is...useless! 

As a streetphotographer I often shoot in manual focus without looking in the viewfinder. A lot of times I'm 'guessing' (by experience) the right distance to my subject -for example 1 meter- and then use the hyperfocal scale on my Leica M lens to set the right aperture. The focus scaling on the Leica lenses are very accurate except....when using an adapter! Unfortunately there are NO adapters without any offset in focus scaling. I'm using the Sony A7s + Voightlander adapter + Leica M 35mm lens and I cannot use the focus scale of the Leica lens anymore. For example ‘the real infinity’ when I focus using EVF and the horizon is sharp; when I look at the focus mark of the lens it is marked at 8 meters! In stead if infinity. So there always seems to be an offset.

 I'm hoping for an adustible adapter to fine tune the offset. 


Hey Jeff,

I feel your pain! I do have a Nikon F to Fujifilm X mount from Novoflex. The manufacturer states a shift in the infinity position, but on my Leica shift lens and Zeiss 28, the infinity marks are still true with the adapter. I cant speak for the other distances, however!

Thanks for reading. I am glad you enjoyed the article!

RE: Jeff..."adustible adapter to fine tune the offset. "

c7Adapter is the correct length.  They even have one for a Shimmable flange

It actually helps when using extension rings for macro. You get extra focus. You get more positive than negative aspects from the whole post-infinity thing.

The distance from the lens to the sensor is not exact in nikon, canon, sony. So manufactures that made general lenses like Tamron and Sigma will make sure they use the longest distance. This result is more "over focus" on some bodies and less on other.


42.00mm for FL and FD, 44.00mm for canon EF. If canon were making post-inifinity focus lanses for FD, we would be able to used them now on our new bodies. So i can see that the position now is better for future changings.

Before modern coatings, the lenses had more abberations, so it was really hard to say if the infinity focus was actually perfect.

Thanks for commenting, Xizario! Good stuff added to the discussion!

Thanks for reading!

One mistake in the article, it should be the Hasselblad and Zeiss lenses were used by NASA's landings on the moon. As far as to my knowledge, Hasselblad wasn't developing lenses for NASA. 

Hi luca,

You are correct. The Hasselblad cameras used on the moon had Zeiss lenses. We have corrected the article to reflect this. Thanks for catching that and letting us know!

Great article, and well researched. I just wanted to mention that the Canon MP-E lens, while being a manual focus lens, does not have a hard stop at infinity. Its maximum focus distance is only a few inches.

Hey DaveK,


It looks like you are correct. I cannot recall where I got that information, but the MP-E's manual actually does make mention of infinity focus.

Good catch! Thanks for reading and commenting!

I started doing photography in the '60s and '70s and due to hard times could not afford to continue.   This year I was able to buy a sony compact mirrorless camera and wondered why I had such a hard time focusing on clouds (fuzzy) and stars (fuzzy balls) only by accident was I able to get focus.  This and the problem with aperture defraction are things I took for granted with film.  I feel like a photo Rip Van Winkle.  Thanks so much for the article.

Hi Roy! Thanks for reading and thanks for the comments!

Yep, you noticed the tolerances in digital are a bit more unforgiving than in film. I think one reason is that when most of us shot film we admired our work at 3x5" or 4x6" or 5x7"...maybe 8x10" if you really liked your picture and had it enlarged. Today, many of us view our images on huge monitors that allow us to see our faults magnified on a much larger canvas! What used to go unnoticed now sticks out in obvious ways. Fun, right?

Keep on shooting!

I noticed my Tamron 17-50 keeps its focus the entire zoom range on my Canon, but with an adapter on my Sony, I have to re-focus at different focal lengths. What's going on here? Is it related to the above concepts?

Hi Noah,

The quick answer is, "I do not know."

In theory, your issue should not be related to infinity focus. I've asked around B&H and no one seems to have a good explanation for your lens' shift from parafocal to non-parafocal with the adapter.

May I ask what adapter it is?

Our current theory is thus:

If the adapter is just a tube with no electronic contacts, the lens should remain parafocal. If the adapter has electronic contacts to allow the lens to talk to the Sony camera, this might be sending autofocus information to/from the lens and causing the shift in focus.

Sorry I am not more help and sorry for the delay in getting back to you. B&H was closed last week.

Thanks for your question and thanks for reading Explora!

Thank you for a very well written and thoroughly researched piece.  I loved the little side bar on the reason for Canon's white lenses.  This was something I always wondered about in the back of my head but never thought there might be a reason to the choice other than marketing, branding and easy brand identification by photographers.  I think that you hit the nail on the head with the fact that technology is taking the tactile fun out of the experience of photography, and so we now see many manufacturers trying to cater to photographers who want the missing pleasure that today's equipment does not deliver. Maybe the hard infinity mark, the DOF markings and the mechanical f/stops will make a comeback with some of the manufacturer's lenses to accompany the retro cameras like the Nikon df.  I know that they stopped using the manual f/stop settings because it makes the cost of the lens less, but never thought that a better fit had anything to do with it, or is that just an excuse?  Thanks again for a great article.

Mr. Fiad Sr,

Thank you very much for your compliments. It was an enjoyable piece to research and write - all driven by my own curiosities!

As far as manual aperture rings, I heard, from a manufacturer representative, that it improved the fit of the lenses, but, in the decades leading up to that invention, I did not really ever hear about people complaining about their lenses not fitting well onto cameras. So, smoke and mirrors to cover a cost savings, or an improvement? Your guess is as good as mine!

I will not get into a soap box about "retro," but it seems like the most successful retro designs are the ones that best integrate the feel of old with the technology of new. So, maybe we will get the tactile pleasures of photography back someday in the future!

Thanks for reading!

Thank you for throwing some light on the subject. With today's computer chips and technology you would think that they could have either put a post at the stop position that would expand and contract with the change of temperature or else would have incorporated a computer program to electronically correct the setting. I'm use to having all of the settings be "correct" rather than having to correct a setting that apparently is "off" by design. I still lament the hard-to-find depth-of-field scale which was a staple of the lens; even though few knew how to use it. Let's hope that lens manufacturers don't follow so-called "logic" of our government by making excuses for more cheaply-made lenses. It wasn't that long ago that we were told how great it was having smaller sensors that gave a 1.5x maginfication rather than keeping everything on an even keel by making 35mm-sized sensors. It's "The Emperor's New Clothes" all over again!

Hello Bill,

Thank you for your comments. I am glad you enjoyed the article.

While researching the piece, it seemed to me that mechanical precision has faded in the name of compromising for technology. Photography is easier than ever today because of technology, but it came at the expense of a certain pleasurable tactile feel and experience of using a mechanical lens.

If you want to read more on the sensor size debate, my $0.02 are here: http://www.bhphotovideo.com/explora/photography/features/dx-vs-fx-its-not-debate-its-choice

Thanks for reading!


Very interesting, pretty well confirms what I had suspected for some time. I haven't had a dig around to see if you've done a similar article about the lack of Depth of Field scales on the barrels of AF primes and zoom lenses. The old much-admired Vivitars had one, but they used a 'trombone' style zoom actuation. There 'justifications' for not not marking lenses, would make another interesting read!

Hi Sam,

Thanks for reading and thanks for your comments! It took a fair bit of digging to get the information on the infinity focus. My guess is that getting info the old DOF markings would be even more difficult! My other theory is that the colorful DOF markings on push-pull zooms went away for some of the same reasons that the infinity hard stop did. I will do some asking around to see if I can find anything official that can be written into a follow-up article.  Thanks again!

Good article. I've been gritting my teeth at the current crop of Canon lenses and the lack of the f-stop ring. Still haven't figured out how to get the maximum depth of field. Really miss the infinity ring. Notice, though, that it is on some of the higher-end, higher priced lenses.

Thanks, Justago!

I know that Nikon claims that by removing the aperture ring, the lenses get a better fit on the camera, but there is definitely something to be said for the tactile pleasures of older lenses - both in their heavier focus rings and clicking aperture dials. Sometimes technology happens at the expense of the total experience!

The Voigtlander brand is owned by Cosina.  Voigtlander lenses are manufactured in Japan.  

Hi Christopher,

You are correct. Many of the established German lens manufacturers now have factories in Japan. However, the company, that has its roots in Austria, and their engineers and staff, are still in Germany.

Do some digging and you will be surprised at how intertwined the family tree of lens manufacturers is! Thanks for reading!

Thank you, John! I am glad you enjoyed it!