Focusing Technique to increase DOF

[sunilmendiratta]

<p>Hi,</p>

<p>I was trying my hand at landscape photography and found focusing difficult to get max DOF.</p>

<p>I figured hyper focal focusing, Helicon focus, focus slice(all are not simple)..and one more option tilt and shift lenses.I was looking for cheaper option and i saw lens-baby's tilt transformer and i thought of using it if at all possible for DOF.</p>

<p>Is it possible to use lensbaby as an alternative to expensive nikon shift/tilt lens? my purpose is to get all objects in focus in a landscape scene.</p>

<p>Regards,<br /> Sunil</p>

[joe_c5]

<p>Focusing at the hyperfocal distance is not difficult, just focus as close as possible while still keeping the furthest objects just barely in focus. Shorter focal length lenses and smaller apertures will give you greater depth of field, potentially at the cost of some resolution lost to diffraction.</p>

<p>A lensbaby tilt transformer should be an alternative to a tilt lens, yes. I cannot say whether it would be a good alternative.</p>

<p>Also keep in mind that when using tilt, the space in focus will be a wedge shape, so tall objects in the foreground may not be in focus.</p>

[simon_hickie1]

<p>Hi Sunil. What camera and lens combination are you trying? </p>

[steve_levine]

<p>A lens baby, is an effects lens, and only allows a single area to be in focus across the plane. It is not an alternative to a shift/tilt (S/T) lens. S/T lenses are actually made for architectural work, not landscapes. They are used mainly to alter perspective, not so much to increase DoF.</p>

<p>In order to maximize DoF you have to use "hyper focal distance" (HFD) focusing. This of course is using the focus point that will include the most of DoF, and include infinity. So by definition you can HFD focus wide open, or stopped down.</p>

<p>So to maximize the DoF in a landscape with a non tilting lens. You need to use a slightly wide to ultra wide angle lens, and stop it down within 1-2 stops from it's smallest aperture opening. And then employ HFD focusing techniques.</p>

[kari v]

<p>Instead of lensbaby effect lenses I'd take a look into medium format lens adapters.<br>

For example this adapter works with cheap P6 lenses:<br>

<a href="http://araxfoto.com/accessories/tilt/">http://araxfoto.com/accessories/tilt/</a><br>

In addition to the Arsat etc. lenses there are old Zeiss design P6 lenses floating around which are of very good quality. Unfortunately 50mm is the widest Zeiss as it's already a wide angle on 6x6 cameras. Mir 45/3.5 is not very good and Arsat 30mm is a fisheye.<br>

6x6 lenses cover 35mm sensor easily even with tilt/shift.</p>

[Alan Marcus]

<p>As you know, depth-of-field is that zone forward and behind the point focused upon that reproduces as acceptably sharp.</p>

<p>Using tables and charts is likely not very effective in the field. Many cameras have depth-of-filed preview buttons but this too is ineffective for most.</p>

<p>A rule-of-thumb that helps a lot:<br>

The zone of Depth-of-field extends 2/3 away and 1/3 backwards from the point focused upon. In other words, the zone is not split down the middle. If you remember this, maybe it will help you focus on an object not too distant, this practice will help you maximize the depth-of-field zone. </p>

[andrewg_ny]

<p>Tilt transformer is essentially a tllt lens (no shift though, right?) so it might be able to be used to effectively increase DoF...you don't mention which camera you're using, I assume you're using a small-sensor MILC. Did you read <a href="../equipment/canon/tilt-shift">this</a>? Should give you some idea of what to expect. I would suggest you seek out users of that specific equipment...I suspect it may be a little hard to control the effect for the kind of results you're hoping for.</p>

<p>Another technique you could look into might be digital focus stacking.</p>

[sunilmendiratta]

<p>MY camera is APS-c sensor Nikon D5000 and i have 18-55 and 55-200 mm lens without infinity mark and distance mark.</p>

[joe_c5]

<blockquote>

<p>A lens baby, is an effects lens, and only allows a single area to be in focus across the plane.</p>

</blockquote>

<p>A tilt lens is a tilt lens. Granted the lens baby tilt transformer is not necessarily a <em>good </em>tilt lens, but the single area in focus is because of the (arguably improper) way people are using it, not because it is intrinsically different. Certainly one of their sample photos showed a fence in focus from close up to fairly far off in the distance. I suppose the lensbaby might have enough field curvature to make it unsuitable for landscape photos, and either way I doubt it would be my go-to lens for landscapes.</p>

<blockquote>

<p>They are used mainly to alter perspective, not so much to increase DoF.</p>

</blockquote>

<p>This is true, however back when nearly any camera intrinsically had tilt and shift capability, the tilt was often used for depth of field.</p>

[leighb]

<p>May I suggest you get a different lens, one that does have aperture ring and DoF scale?</p>

<p>Trying to accomplish this without those tools would be quite difficult.</p>

<p>DoF is strictly a function of focal length and aperture. A tilt/shift lens does not change either of those. It only changes the plane of focus, not the DoF.</p>

<p>- Leigh</p>

[William Michael]

<blockquote>

<p>I was trying my hand at landscape photography and found focusing difficult to get max DOF. I figured hyper focal focusing, Helicon focus, focus slice(all are not simple)..</p>

</blockquote>

<p>I do not understand why using the Hyper Focal Distance is not simple, in most cases. The fact that your lens has no distance markings or infinity mark, is not an handicap to you.<br>

Nor, for many applications, do you need to take sophisticated DoF tables into the field with you, though it is really easy to do so.</p>

<p>Frankly as a rule of thumb for you to follow: for LANDSCAPE work you can use your 18 to 55 kit lens at F/11, between FL = 18mm to FL = 24mm and set your focus at 12ft - that is 4 big steps away from you - (you can pace it out an then focus on that point and then lock the focus). . . and you will be pretty safe for every shot and that will accommodate most Landscape work – where you want Maximum DoF, using your gear: what do you think?</p>

<p>I have written a piece on how to apply DoF / Hyper Focal Distance, "In the Field" here: <a href="00Xbtm">http://www.photo.net/beginner-photography-questions-forum/00Xbtm</a></p>

<p>WW</p>

[joe_c5]

<blockquote>

<p>DoF is strictly a function of focal length and aperture. A tilt/shift lens does not change either of those. It only changes the plane of focus, not the DoF.</p>

</blockquote>

<p>This is true, however if the plane of focus is tilted down to become a wedge including the horizon and foreground objects are short enough, then it is possible for everything from the closest flower to the furthest mountain to be in sharp focus.</p>

<p>Depending on the lenses and apertures, it is possible that the tilt lens could achieve higher resolution than a conventional lens suffering from diffraction blur.</p>

[leighb]

<blockquote>

<p>This is true, however if the plane of focus is tilted down to become a wedge including the horizon and foreground objects are short enough, then it is possible for everything from the closest flower to the furthest mountain to be in sharp focus.</p>

</blockquote>

<p>In sharp focus on what?</p>

<p>If you tilt the lens that far, its image circle will be completely off the film/sensor, and you'll have no image at all.</p>

<p>- Leigh</p>

 

[joe_c5]

<blockquote>

<p>If you tilt the lens that far, its image circle will be completely off the film/sensor, and you'll have no image at all.</p>

</blockquote>

<p>If tilt did move the image circle that far, enough shift could shift it back again.</p>

<blockquote>

<p>In sharp focus on what?</p>

</blockquote>

<p>I’m not certain I understand the question. Objects at a low angle to the ground would be in sharp focus on the sensor or film. Up close these would need to be short, for example, flowers. Far enough away, they could be very tall, for example, mountains.</p>

<p>The diagrams around a third of the way down this link give a general idea. http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses2.htm</p>

<p>When using small apertures instead of tilt, diffraction blur may lower the resolution if very large depth of field is needed.</p>

<p>More details and numbers for tilt can be found at http://www.trenholm.org/hmmerk/VuCamTxt.pdf and http://en.wikipedia.org/wiki/Scheimpflug_principle.</p>

[dan_south]

Do you have a tripod? Download the demo version of Helicon focus and try it out. You'll need to take multiple shots of

your scene, near, far, and middle. The software combines them into one image. It works well as long as nothing is

moving like tree branches blowing in the wind.

 

You could try the lens baby, but I don't think the movements are as accurate as a t/s lens with geared movements. Don't

tilt too much. For wide angle shooting from eye level about one degree is plenty. You'll need more tilt for telephoto lenses

or if you ar shooting close to the ground.

 

T/S lenses are not for landscapes? I don't know where anyone got that idea. T/S lenses are multipurpose. Architecture,

product, landscape, special effects. You can do all of the above with a T/S lens and in most cases the results will exceed

the capabilities of any lens without movements. That said, these lenses are very expensive and it takes some skill and

experience to use then effectively.

 

But my recommendation for a cheap solution would be one of the scaled down versions of Helicon Focus and a steady

tripod.

[m_tt_donuts]

<p>As stated, if you want to get as much of a scene in focus as possible focus 1/3rd into it.... as 2/3rds behind that spot will be in focus and 1/3rd in front. </p>

<p>There's DOF calculators that can be downloaded to a phone if you have an advanced phone.</p>

[Tim_Lookingbill]

<p>Read William W.'s linked explanation and found what he said is true.</p>

<p>I verified it on one of my images you can check out below. Used a 28-80mm Sigma lens set at 80mm, f/8 and focused on infinity which was the building farthest to the back about 200 yards away. Everything between approx. 30 ft and infinity was in focus and the bush in the foreground 10 ft. from the lens was out of focus which agrees with the f/8 markings on the pic of the first lens William posted.</p>

<p>I didn't need those markings to tell me everything I wanted was in focus. I just looked through the viewfinder and saw that it was. The auto focus maxed out focusing on the building 200 yards away.</p><div></div>

[leighb]

<p>If you focus on infinity you're wasting half (figuratively) of your DoF range. This is obvious on traditional lenses with aperture rings and DoF scales.</p>

<p>After you select your aperture, set the infinity focus mark on the far side of the index, one f-number lower than you set, e.g. if you're shooting at f/11, set infinity at f/8. This will give you the maximum DoF, with a safety margin.</p>

<p>- Leigh</p>

 

[kari v]

<p>DoF markings on the lenses are rather conservative.<br>

Agreed, shooting at f11 and setting infinity at f8 is a good place to start, however, there's not much safety margin left really. In Tim's sample image 50ft is already out of focus to my eyes (and shows that focusing at infinity is not the best way to maximize DoF).</p>

[Tim_Lookingbill]

<p>I didn't want to focus on the golfers because the low light wouldn't let me focus very well even with manual. There just isn't enough light (I notice this a lot with digital), so I compromised and just looked through the viewfinder and trusted the overall sharpness of what I saw.</p>

<p>It'ld be nice if all digital lenses came with DOF markings, but you have to work with what you have. And besides anyone with decent editing skills can pull almost at least an extra 20 feet of DOF in a landscape shot. This is what I did with the cropped Raw shot above.</p>

<p>There's so many variables influencing perceived sharpness in a digital capture that a DOF guide isn't really useful in nailing it down. Trees in the distance could be soft because of wind. How would you know that from a DOF gauge. Trying to find the markings on the lens is just going to slow you down as you try to figure and guesstimate distances. I mean how can you tell the difference between an object 30 ft. from another 60 ft. out in the field shooting landscapes?</p>

<p>However, I would suggest calibrating the viewfinder's rendering of sharpness adjusting its diopter comparing against what is seen on the computer or zoomed in on the camera's LCD, but that can slow you down and drain your battery. This still helps me shooting Raw, but I don't nail it every time.</p>

<p> </p>

[sunilmendiratta]

<p>Thanks a lot for all your inputs and special thanks to William W for putting atricle together for begginers.<br>

What i understood is try to take shot with hyperfocal focus but when hyperfocal is not possible then take a shot with different focus point and stack them in photoshop.</p>

<p>Regards,<br>

sunil</p>