Up to 1527MB/s sustained performance

DZ SAVE $300 Z CAM E1 Mini 4K Interchange…

DZ SAVE $1200 Apple 15.4" MacBook Pro with…
SAVE $100 Sigma sd Quattro H Mirrorless
Sigma MC-11 Mount Converter/Lens Adapter…
SAVE $100 Sony a5100 Mirrorless (Black, B…
SAVE $400 Sony a7R II Mirrorless
SAVE $300 Sony a6300 Mirrorless with 16-5…
SAVE $80 Sony DSC-RX100
DZ SAVE $330 LG V30S ThinQ 128GB Smartpho…
NEW! SAVE $100 ZEISS 18mm f/2.8 Bati…
SAVE $1251 ZEISS 15mm f/2.8 Distagon T* ZF…
SAVE $623 ZEISS 135mm f/2 Apo Sonnar T* Z…
$37 FREE ITEMS SAVE $100 Sony DSC-RX100 III
SAVE $200 Sony a7R III Mirrorless
NEW! SAVE $100 ZEISS 18mm f/2.8 Bati…
SAVE $1251 ZEISS 15mm f/2.8 Distagon T* ZF…
SAVE $623 ZEISS 135mm f/2 Apo Sonnar T* Z…
SKU FUGFX50S32L
SKU FUGFX50S45L
SKU FUGFX50S63L
$101 FREE ITEMS SAVE $700 Canon EOS 6D DSLR
$20 FREE ITEMS SAVE $250 Canon EOS 77D DSLR
$20 FREE ITEMS SAVE $450 Canon EOS 7D Mark II DSLR
$101 FREE ITEMS SAVE $500 Canon EOS 80D DSLR with 18-135m…
$115 FREE ITEMS SAVE $650 Canon 18-135mm f/3.5-5.6 EOS 7D…
$556 FREE ITEMS SAVE $800 Nikon D810 DSLR with 24-120mm
$466 FREE ITEMS SAVE $1100 Nikon D750 DSLR with 24-120mm
$468 FREE ITEMS SAVE $470 Nikon D500 DSLR with 16-80mm
$61 FREE ITEMS SAVE $570 Nikon D7500 DSLR with 16-80mm
SAVE $300 Sony 24-70mm f/4 Vario-Tessar T…
$20 FREE ITEMS SAVE $450 Canon EOS 77D DSLR with 18-135m…
SAVE $400 Olympus OM-D E-M1 Mark II Mirro…
SAVE $350 Olympus OM-D E-M5 Mark II Mirro…
SAVE $400 Panasonic Lumix DMC-GX85 Mirror…
SAVE $300 Panasonic Lumix DMC-G7 Mirrorle…
SKU SOA7R324704K
SKU APMBPTMLH430
SAVE $1500 Pentax 645Z Medium Format DSLR
SAVE $200 Pentax K-1 DSLR
$466 FREE ITEMS SAVE $1100 Nikon D750 DSLR with 24-120mm
$466 FREE ITEMS SAVE $500 Nikon D750 DSLR
SAVE $100 Sigma 30mm f/1.4 sd Quattro Mir…
SAVE $450 Canon EOS 7D Mark II DSLR Body…
SAVE $100 Sony a6000 Mirrorless Body
$9 FREE ITEMS SAVE $160 Steiner 8x32 XC Binocular
DZ SAVE $120 Think Tank Photo Retrospecti…
$98 FREE ITEMS DZ SAVE $450 Interfit S1 500Ws HSS TTL Ba…
DZ SAVE $150 JBL Reflect Aware Sport Earp…
DZ SAVE $70 Vanguard Sedona 51 DSLR Back…
$44 FREE ITEMS DZ SAVE $130 ikan DH7 7" Full HD HDMI Mon…
DZ SAVE $60 Kolibri U818A Discovery Delt…
DZ SAVE $70 Kopul SDI-PPC Stereo Multime…
DZ SAVE $10 Joby Action Grip
DZ SAVE $30 Bolt VC-310C Compact On-Came…
DZ SAVE $40 Westcott Rapid Box - 26" Oct…
DZ SAVE $100 Wooden Camera Unified Cage
DZ SAVE $40 Celestron 15x70 SkyMaster Bi…
DZ SAVE $30 Bolt VC-310F Compact On-Came…
DZ SAVE $700 ikan IB508-v2 Bi-Color LED 3…
DZ SAVE $130 Think Tank Photo Lily Deanne…
DZ SAVE $42 Lowepro Passport Sling Camer…
DZ SAVE $100 Dracast LED140 Halo Bi-Color…
DZ SAVE $30 Bolt VC-310N Compact On-Came…
DZ SAVE $120 Domke Next Generation Herald…
DZ SAVE $25 Lowepro S&F Quick Flex Pouch…
DZ SAVE $90 E-Image 760AT Aluminum Tripo…
DZ SAVE $130 Think Tank Photo Lily Deanne…
$35 FREE ITEMS DZ SAVE $726 Redrock Micro microMatteBox…
DZ SAVE $30 Vello FreeWave Plus Wireless…
DZ SAVE $15 Pacsafe Carrysafe 50 Anti-Th…
DZ SAVE $15 HUBSAN X4 Plus H107P Quadcop…
DZ SAVE $45 Olympus LS-P1 Portable Handh…
DZ SAVE $160 Rokinon 12mm f/2.8 ED AS IF…
DZ SAVE $15 Joby UltraFit Sling Strap Fo…
DZ SAVE $30 Nintendo 2DS XL Handheld Gam…
$11 FREE ITEMS DZ SAVE $200 MagiCue Mobile Teleprompter…
DZ SAVE $150 ASUS 15.6" VivoBook S15 S510…
DZ SAVE $16 Ruggard Fabric Rain Shield M…
DZ SAVE $12 Ruggard Fabric Rain Shield S…
DZ SAVE $40 Vanguard Reno 41 DSLR Backpa…
DZ SAVE $17 Hoya 55mm Ultraviolet UV (O)…
DZ SAVE $130 Swann 4-Channel 1080p NVR wi…
DZ SAVE $100 Vinta S-Series Backpack Trav…
DZ SAVE $55 Luxxetta L-Shaped Office Com…
DZ SAVE $300 Rokinon 24mm T1.5 Cine DS
DZ Canon Mugs Lens Wristlet (70-200mm)
DZ SAVE $200 Rokinon 14mm f/2.8 AF
DZ SAVE $40 Magnus PV-7451M Tripod/Monop…
DZ SAVE $30 Think Tank Photo Hubba Hubba…
DZ SAVE $40 Ruggard DSLR Parka Cold and…
DZ SAVE $25 Roland GO:Mixer Audio Mixer…
DZ SAVE $23 IK Multimedia iKlip Grip Sma…
DZ SAVE $22 Vello ShutterBoss II Timer R…
DZ SAVE $40 Polsen PCR-65 Cardioid Conde…
DZ SAVE $270 Xerox WorkCentre 3315 All-in…
DZ SAVE $50 Vello Extendá Wi-Fi C…
DZ SAVE $40 Bolt P12 Compact Battery Pac…
DZ SAVE $40 Elvid OptiView 100 3.2" LCD…
DZ SAVE $40 Bolt P12 Compact Battery Pac…
DZ SAVE $20 Musicians Value C3 Series CS…
DZ SAVE $90 Bolt Cyclone DR PP-400DR Dua…
DZ SAVE $40 Bower Flash Accessory Kit
DZ SAVE $220 Oben CC-2381L 3-Section Carb…
DZ SAVE $17 Pelican 1910B MityLite LED F…
DZ SAVE $55 Dracast Camlux Pro Bi-Color…
DZ SAVE $120 Senal UTM-86-HRS Lavalier Mi…
DZ SAVE $40 Bolt P12 Compact Battery Pac…
DZ SAVE $70 Prima Photo Small Travel Tri…
DZ SAVE $120 Marantz Professional MPM-200…
$12 FREE ITEMS DZ SAVE $50 Tascam VL-S3 14W + 14W 3" Po…
DZ SAVE $25 Wein HS Hot Shoe Slave
DZ SAVE $80 Interfit F5 Two-Head Fluores…
DZ SAVE $60 Corel VideoStudio X9 Ultimat…
DZ SAVE $17 Pelican 1910B MityLite LED F…
DZ SAVE $22 Vello ShutterBoss II Timer R…
DZ SAVE $300 Vello Nikon F Lens to Sony E…
DZ SAVE $50 Peak Design Canon EF Capture…
DZ SAVE $200 Denon Amplified Speaker Lect…

View all 335 deals…

Focusing Zeiss DSLR Lenses For Peak Performance PART TWO: Tips and Best Practices for Sharply Focused Images

Last updated 2016-02-29 - Send Feedback
Related: how-to, focus, Zeiss

See best Zeiss lenses wish list and Nikon wish list and Canon wish list at B&H Photo.

Search this site for: Zeiss Otus, Zeiss Milvus, Zeiss Loxia, Zeiss Batis

In part 1, the challenges of making sharp images were covered, with focus accuracy the primary variable. Here in part 2, best practices for addressing those challenges are presented.

Choose focus wisely

Choosing where to focus can be harder than it sounds. In general, focus on what must be critically sharp, letting everything else fall into place.

In scenes with pronounced near-to-far detail, some range of the scene is not going to be fully sharp, even at f/13 or so. Thus the choice of what to focus on depends on what is most important. The contextual elements usually need not be fully sharp; what matters is critically sharp focus on the key elements. Also, leaving some foreground and background separation via some level of blur offers a pleasing juxtaposition of sharp/unsharp, and some unsharp areas can make the sharp areas look even sharper by comparison.

The classic “1/3 into the scene and stop down” rule is marginal. While it works well in some average sense, it is often non-optimal in either depth of field or visual impact. Moreover, field curvature can be a significant factor particularly for near-infinity focus. It is usually better to bias focus at or close to the elements of the scene that need to be critically sharp: a blurred horizon is rarely pleasing if it is a strong part of the composition. As an obvious example of placing focus on what matters most, consider a portrait with trees in the background: the person’s eyes should be critically sharp; the ears and the trees don’t matter much.

Which brings us back to focus accuracy as a critical factor. One “solution” is stopping down for depth of field (a deeper zone of sharpness). But this has serious limits: conventional depth of field tables use a 30 micron dot size (circle of confusion), which is about 37X larger in area than a pixel on a 36-megapixel full-frame DSLR!

As a rule of thumb for very fine detail on a high-res DSLR, figure three (3) stops less leeway than a DoF table suggests. For example, if the DoF table claims that f/4 yields the desired DoF, then f/11 is the actual aperture for very fine details over that range—but beware diffraction from stopping down too far (as previously shown). Also, depth of field tables are a theoretical best, and often wildly overestimate real lens behavior. For example, with many wide angle lenses, minimal depth of field gains are seen for the first two or even three apertures, with various aberrations keeping actual depth of field far less than the theoretical, particularly in outer areas of the frame.

Video: Discussion of WHERE to Focus

Up to 1527MB/s sustained performance

Tips for focusing with the optical viewfinder

Live View (discussed further on) is a far more reliable approach than the optical viewfinder, but if the optical viewfinder must be be used, the tips in the video and below raise the odds for accurate focus.

Video: Tips for Focusing with the Optical Viewfinder

 

Tip #1: set the diopter adjustment on the viewfinder to correct for any minor acuity issues. This is very important, if only to avoid eye fatigue. To adjust, enable any available display items for your camera such as superimposed gridlines. Defocus the lens for a strongly blurred image, then adjust the diopter setting until the gridlines or similar markings on the focusing screen are crisp and clear. If necessary, tape down the diopter adjustment so it won’t move.

Tip #2: test yourself to set expectations: shoot ten identical frames wide open, refocusing for each frame (f/1.4 or f/2 lenses will be most revealing). Use a tripod to eliminate body movement as a factor. Shoot one reference frame focused using magnified Live View. Check the focus results in the resulting images. Try this both by eye and also using the camera Focus Assist feature.

Tip #3: focus bracket: take several shots, refocusing each time. Alternately, focus and shoot, then using the distance scale on the lens shoot two more frames, one closer and one farther, using the distance scale (using very small adjustments). One of these shots may be optimal. All this is avoided by using Live View, so use Live View when feasible.

Tip #4: use an eyepiece magnifier. Sometimes the focusing eye needs a little help. For full-frame Nikon, the Nikon 1.2X DK-17M Magnifying Eyepiece is excellent, and retains full view of the frame. Nikon APS-C cameras accept the 1.17X DK-21M magnifying eyepiece. Canon magnifying eyepieces seem to be only for APS-C models.

Tip #5: test for and adjust the Focus Assist feature with each manual focus lens. Focus from near to far distance for consistent behavior. Test the consistency and accuracy by refocusing for 10 frames or more, on several different subjects. If there is a consistent error in one direction (too close or too far), adjust the AF Fine Tune feature as found in current Canon and Nikon DSLRs. However, if a lens has focus shift, the adjustment can be optimized for one aperture only.

Tip #6: stop down slightly. It may be helpful to focus with the lens slightly stopped down by holding the depth of field preview button down while focusing. This is awkward, but it can improve crispness of the image for some lenses and make it easier to focus (as well as partially address focus shift). Try f/2 or f/2.8 for f/1.4 lenses.

Tip #7: swap the focusing screen for one better suited for manual focus, even if the camera vendor offers no options; see for example FocusingScreen.com. However, the replacement focusing screen might not appeal for general use (with autofocus lenses or having a split image or microprism obstruct the view). More problematic: unless the tolerances are perfect, the camera may also require adjustment (shimming) to make the light path distance match the distance to the sensor.

MacPerformanceGuide.com

Best Practice: Focus Using Live View

Live View is best used on a tripod, but it is also feasible handheld (see video). A focusing loupe is all but essential, such as the Zacuto Z-Finder (highly recommended for stills or video). A loupe is invaluable for perceiving fine details, cutting glare on the rear LCD, and blocking sidelight from the eye itself.

Live View focusing delivers major benefits:

  • The Live View image is from the imaging sensor, so there is no “dual path” discrepancy between the focusing sensor and the imaging sensor.
  • Focusing can be at zoomed-in magnification for precise focus on a very small portion of the subject. This allows focusing on a very specific area, such as the stamen inside a flower, a particular small object among others, a leading or interior branch of a tree, etc.
  • Focusing can be anywhere in the frame. Even field curvature can be dealt with by scrolling across the frame to assess the “balance” of sharpness. Depth of field can be checked as well.
  • Focusing can be done at a suitable aperture, thus dealing directly with focus shift.
  • Infinity focus can be determined precisely regardless of the lens or temperature or camera body, critical for astrophotography and similar applications.

Live View handheld too

Using Live View for tripod-based shooting is a given, but handheld use of Live View with a focusing loupe works well for pinpoint focus accuracy, as well as offering excellent shooting stability. And because the mirror is already up, there is no mirror slap vibration. Many shooting situations afford ample time to focus and expose in Live View.

Video: PERFECT focus using the rear LCD Live View + focusing loupe

Tips for using Live View

Cameras vary in settings (see the Canon and Nikon specific videos), but here are the things to do and to configure:

3X Focusing loupe for rear LCD
(Zacuto Z-Finder)
  • Prefer magnified view for maximum accuracy—something around 10X or 12.5X—1 or 2 steps off maximum magnification is most useful in most cases.
  • Especially for aging eyes (presbyopia), a high quality focusing loupe is essential for discerning fine detail. It also excludes stray light and improves contrast for easy focusing.
  • Manual or Aperture priority are desirable, since controlling the aperture is a key consideration for focusing.
  • With some cameras the JPEG settings affect the Live View rendering. Using more sharpening and contrast can be helpful for a more clear image in Live View.
  • Some cameras have an option to auto-adjust brightness or to show the exposure as set on the camera.
  • With many DSLRs, a button can be programmed that goes directly to some chosen level of magnification.
  • For lenses with focus shift, focus at the shooting aperture (see details that follow).
  • Some cameras have a focus peaking function that may be useful at times. However, too-eager focus peaking can sometimes obscure fine detail necessary for precision focus.
Our trusted photo rental store

Using Live View for Nikon

Nikon’s approach to Live View is not consistent across the model line; with the Nikon D810 and most other full-frame models, the camera stops the lens down to the shooting aperture. For example, if the camera is set to f/8, then Live View is at f/8 (see video).

Tip: on the Nikon D810, the of field preview button (“Pv”) at camera front toggles between the shooting aperture and wide open (no need to hold down the button), useful for lenses that are best focused wide open (and when lighting conditions are not too bright).

Live View focusing procedure on the Nikon D810 and various other Nikon bodies:

  1. Set the aperture to the best focusing aperture* (usually wide open).
  2. Focus in magnified view using a high-quality focusing loupe.
  3. Set the lens to the desired shooting aperture, expose the image***.

With other Nikon models (Nikon APS-C DSLRs, certain others), the camera keeps the lens diaphragm fully open, similar to what Canon does. Focusing at a stopped-down aperture with these models thus requires holding down the depth of field preview button.

* Best focusing aperture for a high performance lens is wide open or one stop down, which assumes a freedom from focus shift. If focus shift is present, focus at the shooting aperture, up to f/4, as discussed.

** For tripod use, use the self timer or remote release to avoid disturbing the camera.

Video: Configuring Nikon DSLRs for Live View

Video: Step by Step Live View on Nikon D810

Up to 1527MB/s sustained performance

Using Live View for Canon

Canon DSLRs generally maintain the lens diaphragm wide open in Live View, but may unpredictably stop down the lens to an arbitrary aperture when the light is too bright (usually only an issue with f/1.4 or f/2 lenses). Focusing at a known aperture can thus require holding down the depth of field preview button, to force the lens to that aperture.

Live View focusing on Canon DSLRs is as follows:

  1. Focus* in magnified view using a high-quality focusing loupe.
  2. Expose the image**.

* If focus shift is present, focus at the shooting aperture, up to f/4, as discussed. This may require holding down the depth of field preview button to force a particular aperture.

** For tripod use, use the self timer or remote release to avoid disturbing the camera

Video: Configuring Canon DSLRs for Live View

Video: Using Live View on Canon DSLRs for manual focus lenses

Focusing a lens with focus shift

If focus is obtained with the lens stopped down to the shooting aperture, there can be no discrepancy, since focusing and shooting aperture are the same.

Focusing at the shooting aperture (using Live View) is the ideal solution through about f/4. Aperture f/4 tends to be the practical limit for focusing for these two reasons:

  • Stopping down past f/4 can be too dark and grainy in dim conditions such as dusk. The lens will have to be opened up to a wider aperture.
  • Beyond f/4, increasing depth of field makes discerning peak focus for a specific area more difficult. The risk is that the zone of focus is biased too far forward or too far back instead of being centered around the chosen area.

Focusing stopped down with some cameras can be awkward because the camera keeps the lens at full aperture unless the depth of field preview button is held down (applies to Canon DSLRs and certain Nikon models). With Nikon D810 Live View as shown in this video, the camera keeps the lens stopped down to the aperture set on the camera.

Video: Focus shift with the Zeiss 85mm f/1.4 Planar

MacPerformanceGuide.com

Assessing field curvature, balancing focus

Field curvature with Zeiss DSLR lenses is well controlled, but with high-res DSLRs everything helps. Understanding the field curvature characteristics of a lens along with relatively small focus tweaks appropriate for the arrangement of subject matter in an image can provide an “upgrade” in total image sharpness, even stopped down. For example, with a distant landscape shot, more distant focus at center works well for a wide angle lens whose field curvature arcs focus closer in the outer areas. Examples include the Zeiss DSLR 18/3.5, 21/2.8 and 25/2 Distagons.

Live View can reveal field curvature: scroll across the (magnified) frame to detect sharpness variations at the same distance, using a scene with uniform subject matter such as a grassy hillside or the wall of a building. Effects are relatively subtle however, so shooting the range of apertures from wide open to f/11 and then examining the series on the computer is often more instructive. Even forgetting field curvature, examining various areas of the frame in Live View can be helpful in seeing how focus “cuts” through the subject, which may lead to a slightly better choice of focus for items of interest in a particular scene.

Field curvature can sometimes change with aperture in the outer areas of the frame via peripheral focus shift; the Zeiss Otus 28mm f/1.4 Distagon behaves this way in the outer zones, an optical design choice that comes from balancing aberrations.

Our trusted photo rental store

Conclusion

Gaining skill and experience with manual focus opens up a whole new set of optical choices, namely the large selection of Zeiss DSLR lenses for Nikon and Canon. That skill set also applies to manual focus with autofocus lenses, which may be necessary or even preferred in some shooting situations.

Lloyd’s photography blog is found at diglloyd.com; it covers many brands, lenses, cameras. See diglloyd Making Sharp Images for much more. In-depth review coverage of the Zeiss DSLR lenses for Canon and Nikon is found in Guide to Zeiss. By subscription.

MacPerformanceGuide.com

B&H Deal ZoneDeals by Brand/Category/Savings
Deals expire in 11 hours unless noted. Certain deals may last longer.
$999 SAVE $700 = 41.0% $101 FREE ITEMS Canon EOS 6D DSLR in Cameras: DSLR
$649 SAVE $250 = 27.0% $20 FREE ITEMS Canon EOS 77D DSLR in Cameras: DSLR
$1049 SAVE $450 = 30.0% $20 FREE ITEMS Canon EOS 77D DSLR with 18-135mm USM in Cameras: DSLR
$1349 SAVE $450 = 25.0% $20 FREE ITEMS Canon EOS 7D Mark II DSLR in Cameras: DSLR
$1299 SAVE $500 = 27.0% $101 FREE ITEMS Canon EOS 80D DSLR with 18-135mm in Cameras: DSLR
$229 SAVE $170 = 42.0% $99 FREE ITEMS Dracast CamLux Max Bi-Color 3-Light Kit in All Other Categories
$7 SAVE $10 = 58.0% Joby Action Grip in Video: Camcorders
$2497 SAVE $470 = 15.0% $468 FREE ITEMS Nikon D500 DSLR with 16-80mm in Cameras: DSLR
$1497 SAVE $500 = 25.0% $466 FREE ITEMS Nikon D750 DSLR in Cameras: DSLR
$1997 SAVE $1100 = 35.0% $466 FREE ITEMS Nikon D750 DSLR with 24-120mm in Cameras: DSLR
$1747 SAVE $570 = 24.0% $61 FREE ITEMS Nikon D7500 DSLR with 16-80mm in Cameras: DSLR
$3297 SAVE $800 = 19.0% $556 FREE ITEMS Nikon D810 DSLR with 24-120mm in Cameras: DSLR
$1697 SAVE $200 = 10.0% Pentax K-1 DSLR in Cameras: DSLR
$599 SAVE $200 = 25.0% Rokinon 14mm f/2.8 AF in Lenses: DSLR
$100 SAVE $100 = 50.0% Sachtler Dr. Bag - 3 in All Other Categories
$1998 SAVE $400 = 16.0% Sony a7R II Mirrorless in Cameras: Mirrorless
$368 SAVE $80 = 17.0% Sony DSC-RX100 in Cameras: Point and Shoot
$648 SAVE $100 = 13.0% $37 FREE ITEMS Sony DSC-RX100 III in Cameras: Point and Shoot
$300 SAVE $160 = 34.0% $9 FREE ITEMS Steiner 8x32 XC Binocular in All Other Categories
$790 SAVE $400 = 33.0% Teradek COLR in Computers: Peripherals
$1399 SAVE $100 = 6.0% ZEISS 18mm f/2.8 Batis in Lenses: Mirrorless

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2008-2017 diglloyd Inc, all rights reserved.