"IMHO": Getting More With Macro |
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Wētāpunga
Senior Member Joined: 02 September 2007 Country: New Zealand Location: New Zealand Status: Offline Posts: 6815 |
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Topic: "IMHO": Getting More With Macro Posted: 29 February 2008 at 01:47 |
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by wetapunga This is a quick outline of the main techniques of macro-photography. It is aimed chiefly at Minolta and Sony owners. It also tends to reflect my bias towards the photography of insects and spiders. In macro-photography, there are three basic issues 1. Magnification 2. Light 3. Stability A photographer has to have a solution to each of these aspects to take a good photo. We will start with magnification. Magnification is the indispensable element of macro-photography. There are several ways to achieve a high magnification. Most macro-photographers will have a dedicated macro-lens. These typically come in focal lengths between 50mm and 180mm. Macro-lenses are typically much sharper than zoom lenses with a macro function. The magnification ratio delivered by many of these lenses is 1:1. They are good for larger subjects, but deliver less detail on subjects less than 1 cm long.
Macro lenses however, are tricky to obtain on a tight budget. Fortunately there are other options. Note that only some of the approaches listed below, allow you to focus and compose the shot with the aperture wide-open. Being able to focus with the view finder at maximum brightness, will increase the odds of sharp, detailed images. First, you can try reversing a lens. Ideally this should be a lens of 50mm focal length or less, and be reasonably sharp to begin with. It is an ideal way to use second-hand manual-focus lenses, or even lenses from other manufacturers. The lens is mounted by its filter thread, to the body of the camera. Minolta Dynax camera with reversed lens Reversing rings can be made or bought fairly cheaply. Note that there will not be any electrical contact between the lens and camera. This means your camera has to have the option to press the shutter when the camera thinks there is no lens present. Reversing Ring Fixing the aperture will be challenging. Macro-photography is typically done at f12-f20. Older MC or MD lenses may allow manual adjustment of the f-stop. AF lenses tend not to. The solution is to mount the AF lens to the camera, select the f-stop (aperture) you want, then press the DOF preview button. While holding that down, press the lens release button and twist the lens off. It should stay in the locked aperture. Three hands or high manual dexterity helps! If your camera lacks the DOF preview button, you will have to use an older manual focus lens. Fortunately these are often available second-hand at good prices. The advantage of this technique is that it is very cheap. You can get higher magnification ratios than proper macro lenses. Did I mention it is very cheap! It has some disadvantages. It is awkward with AF lenses to lock the aperture. As the aperture is locked at a small f-stop, you don't get much light coming through the viewfinder. This hinders focus as the subject will appear dimmer than for a normal lens. The minimum focal distance is much shorter than a proper macro lens. Focus for this setup is achieved by carefully moving the camera back and forth until the subject appears focused. The focus ring won't help. A practical disadvantage is that you are more likely to spook the subject. You can't easily change the aperture for AF lenses. You are exposing the rear of the lens to the environment, and there is a small risk of damage to the rear lens-element. These are typically not coated with the same protective layers as the front-element. Second, you can try coupling two lenses together. This involves adding a second lens (typically a 50mm prime) to the first lens already on the camera. Dorset Mike has a useful post on this technique The aperture on the second lens may have to be set manually or jammed (gulp) at the appropriate setting (wide open). This is also a cheap way to get a magnification effect. Note that the second lens is attached to the first lenses' filter thread, so the arrangement can be rather heavy. The arrangement is fairly cheap if you have a suitable lens, the first lens retains electrical contact with the camera (but not the second), and you can get high magnification ratios. Disadvantages are that the image is passing through a lot more lens elements so image quality can suffer if the lenses are low quality, and you have to get much closer to the subject. Also the weight of the system is awkward. Like the reversed-lens approach, focus is achieved by moving the camera back and forth until the subject is properly focused. Third, you can use bellows. I can do no better than to recommend the Tpetpe's post on this and Pete Ganzel's homepage. Bellows are ideal for studio type shots, especially if you have stacking software to generate an image with a high DOF. Bellows are however, awkward in the field and especially for elusive subjects. Fourth, you can use extension tubes. An extension tube sits between the camera and the rear of the lens. There is no glass in the tube. It increases the distance between the sensor and the lens, increasing the magnification effect. Extension tubes can be constructed or bought. Commercial versions often retain electrical contacts, so the camera is still connected to the lens. If the tube is without electrical contacts you will have to manually set the aperture of your lens. Extension tubes are a straightforward and simple way to achieve magnification. There is no risk the image will be distorted by poor quality glass- because the tube doesn't have any! You have to get closer to the subject to focus the camera. It can be cumbersome to switch tubes in the field. You can compose and focus your shot with the aperture wide open. Fifth, you can use adapters or diopters. Diopters look like filters, are relatively cheap, and very portable. They are easy to add and remove in the field. In general however, image quality tends to suffer with diopters. Against this, you need to balance their ease of use and economy. Another advantage is you don't lose any f-stops with this technique. This means you aren't forced to shoot at a high ISO or have an aggressive lighting approach. To maintain image quality, one option is to get very high grade (achromat) diopters or adapters. Raynox for instance, makes several magnification options. Raynox adaptor with 6x diopter Alpha camera with Raynox adapter I've been using the Raynox option because it is quite portable to carry and generates effective pictures. It does restrict your ability to add a ringflash or light to the lens. It also produces serious vignetting with lenses with a diameter greater than 55mm. Note, all of these techniques can be used alongside a macro lens and do not have to be a replacement for it
The other elements of taking a good photo are lighting and stability. An external flash is in my experience, almost mandatory. Once you start increasing magnification and reducing apertures, there's not a lot of light coming through the lens. The on-board camera flash is typically too weak. The nice thing about the Sony alpha cameras is they come already set up for wireless shooting. I almost always use my flash in wireless mode off-camera to get more even lighting. Also, reflectors (pieces of white card- or even a paper-towel!) can improve the distribution of light. More expensive options include getting a ring-flash (which won't work if you don't have the lens filter-ring facing outwards, e.g. you reverse your lens) or a dedicated macro-flash kit. Having some cheap LED lights from a hardware store can also be set up to reduce harsh shadows. Not everything has to cost a lot of money, if you can work out what the appropriate solution should be. Many macro-photographers will acquire a tripod. This generates a lot of stability, but may not be a good option for fast moving subjects. If you invest in a tripod, it can be invaluable to have one that can be deployed very low to the ground. These tripods are often marketed as being specialised for macro photography. Other tricks to improving stability include using the camera's mirror lockup function or a remote commander to release the shutter. For handheld shots, the SSS function is handy. Also, sometimes you may be able to rest the camera on the ground or branch adjacent to the subject. Another useful tool is the macro-rail or rack. The camera is mounted on the macro-rail, and the setup is secured to a tripod. The macro-rail provides fine adjustments along 2-3 planes to the focus point. It helps to not have too much weight attached to the lens when making these adjustments. Ultimately, the most important element to a good macro-shot is the photographer. It is your skill base that will matter the most. Macro-photography, especially when you get to magnifications >1:1 have very narrow depths-of-field (DOF). Selecting a good lighting angle, a good focus plane etc, are skills you need to develop. A crucial element to this skill is holding the camera (hence sensor) parallel to the focal plane of the subject. This will maximise the focused area of the subject. And as you develop, you need to keep thinking about, and experimenting with the methods to achieve magnification, lighting and stability.
Edited by brettania - 12 October 2012 at 12:06 |
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α1, α7cii- Voigtländer 15/4.5, 110/2.5 M; Zeiss Loxia- 21/2.8, 35/2, 50/2 & 85/2.4, Zeiss Batis- 85/1.8 & 135/2.8; Sony 24-105/4 & 100-400/4.5-5.6; Sigma 70/2.8 M; Sony 135/2.8 STF
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brettania
Admin Group Dyxum factotum Joined: 17 July 2005 Country: New Zealand Location: Auckland Status: Offline Posts: 20649 |
Post Options Quote Reply Posted: 29 February 2008 at 02:07 | ||
Thanks for this chthoniid.
We get a lot of newbie-type of enquiries, and this will be an excellent "primer" for them. It has been indexed under Articles (top of the left column on most pages). |
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dogears
Senior Member Joined: 05 September 2006 Country: Philippines Location: Philippines Status: Offline Posts: 9530 |
Post Options Quote Reply Posted: 29 February 2008 at 02:10 | ||
for the write-up
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superx2won
Senior Member Joined: 14 January 2008 Country: Malaysia Location: Malaysia Status: Offline Posts: 1067 |
Post Options Quote Reply Posted: 29 February 2008 at 04:41 | ||
Just curious,... extension tube + diopters + tripod.. With this configuration, will i get a bigger magnification and quality image?
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A900 + A65 + KM 7D + Maxxum 9 + S16-105
Learn repairing Minolta lens --> Join my Photography-lab.com blog for step by step guide |
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brettania
Admin Group Dyxum factotum Joined: 17 July 2005 Country: New Zealand Location: Auckland Status: Offline Posts: 20649 |
Post Options Quote Reply Posted: 29 February 2008 at 05:11 | ||
Obviously magnification will increase, but in terms of quality a lot would depend on the inherent IQ of the lens and the diopters. The use of a tripod will certainly help if you want to work at low ISOs, or use longer exposures because the subject is in dark surroundings. |
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Wētāpunga
Senior Member Joined: 02 September 2007 Country: New Zealand Location: New Zealand Status: Offline Posts: 6815 |
Post Options Quote Reply Posted: 29 February 2008 at 05:55 | ||
An extension tube plus diopter setup will increase magnification. Nonetheless, as you push the limits of magnification there are two obstacles to sustaining image quality. The first is that you risk out-resolving the sensor on your camera. It may not be fine enough to record the detail you're after. The second is you will need even more light coming through the lens. If your camera has to compensate by increasing the ISO value, the noise-level of the photo will be inflated.
High magnifications of course, will inflate any camera shake so this would also have to be taken into account. |
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α1, α7cii- Voigtländer 15/4.5, 110/2.5 M; Zeiss Loxia- 21/2.8, 35/2, 50/2 & 85/2.4, Zeiss Batis- 85/1.8 & 135/2.8; Sony 24-105/4 & 100-400/4.5-5.6; Sigma 70/2.8 M; Sony 135/2.8 STF
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polyglot
Senior Member Joined: 25 June 2007 Country: Australia Location: Australia Status: Offline Posts: 3622 |
Post Options Quote Reply Posted: 29 February 2008 at 06:38 | ||
thanks for the writeup, chthoniid! Do you have links to examples of stacking software for building more DOF?
Out-resolving the sensor is never a problem, you'll still always capture as much information as the sensor is capable of! The only problem with resolution is when the optical arrangement doesn't have enough. The problem is that when designing a lens, it is corrected for spherical aberration and these corrections (depending on how they're applied) work best within a certain range of focus distances. So as you increase magnification via increased extension, you are likely to encounter softness. Some lenses don't have a very good min-focus distance - sometimes this will be due to mechanical constraints, but sometimes it's just that the sharpness at high magnifications of some lens designs is poor. With a dedicated macro lens that should be corrected all the way up to 1:1, you shouldn't encounter softness until very high magnifications like 3:1 (i.e. an 8mm subject on APS). However if you put a normal lens (say a 50/1.7) on extension tubes or bellows, the magnification will go up but the image quality may be poor as the focus distance gets very very short. As a further note, extension tubes are typically more effective (in terms of magnification gained) on shorter lenses, for example. |
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Wētāpunga
Senior Member Joined: 02 September 2007 Country: New Zealand Location: New Zealand Status: Offline Posts: 6815 |
Post Options Quote Reply Posted: 29 February 2008 at 07:46 | ||
I've heard about- and seen good things- with CombineZ5. It's popularity may owe something to the fact it's free , but even so, a simple interface and fairly intelligent stacking system has much to recommend it. I really haven't done much comparisons of different software. My subjects are usally moving around a bit too much to get a good sequence.
Thanks for the elaboration on lens design- so basically most lenses aren't optimised for high magnifications, but macro lenses are more likely to sustain performance as the magnification climbs. I think the trick to macro-photography is often not the technical side of pushing the magnification higher and higher. It's often appreciating what will make a good shot and what you need to get it- lighting and stability issues are easy to overlook. |
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α1, α7cii- Voigtländer 15/4.5, 110/2.5 M; Zeiss Loxia- 21/2.8, 35/2, 50/2 & 85/2.4, Zeiss Batis- 85/1.8 & 135/2.8; Sony 24-105/4 & 100-400/4.5-5.6; Sigma 70/2.8 M; Sony 135/2.8 STF
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dogears
Senior Member Joined: 05 September 2006 Country: Philippines Location: Philippines Status: Offline Posts: 9530 |
Post Options Quote Reply Posted: 29 February 2008 at 08:20 | ||
Next write-up: Macro Panning |
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superx2won
Senior Member Joined: 14 January 2008 Country: Malaysia Location: Malaysia Status: Offline Posts: 1067 |
Post Options Quote Reply Posted: 29 February 2008 at 09:56 | ||
Thansk you : Chthoniid and other dyxum member. The explaination do help me to understand more on marco photography.
I am so excited to learn on Macro. Go go go : macro Panning.. |
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A900 + A65 + KM 7D + Maxxum 9 + S16-105
Learn repairing Minolta lens --> Join my Photography-lab.com blog for step by step guide |
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dilettante
Senior Member Joined: 02 April 2007 Country: United Kingdom Location: United Kingdom Status: Offline Posts: 2981 |
Post Options Quote Reply Posted: 29 February 2008 at 10:13 | ||
Excellent summary chthoniid.
I question one part:
I don't think this is the case. On board flashes are typically GN12, good enough for a portrait or to fill a small room, so lighting a spider at 30cm should be no problem. The issue is directing and diffusing the light to the subject, as the pop-up flash is not well placed for illuminating something very close to the lens. |
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brettania
Admin Group Dyxum factotum Joined: 17 July 2005 Country: New Zealand Location: Auckland Status: Offline Posts: 20649 |
Post Options Quote Reply Posted: 29 February 2008 at 11:41 | ||
Another good source of reference on the use of bellows with KM and Sony dSLRs is in Dyxum member Pete Ganzel's homepages.
This perhaps could be incorporated in the OP. |
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Dinostrich
Senior Member Joined: 11 July 2007 Location: England Status: Offline Posts: 1161 |
Post Options Quote Reply Posted: 29 February 2008 at 12:04 | ||
Worth bearing in mind the benefits that can accrue from using either the AngleFinder Vn or the Magnifier Vn in certain circumstances.
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I shot some film yesterday. I was told last night that film was dead so today I shot some more.
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Wētāpunga
Senior Member Joined: 02 September 2007 Country: New Zealand Location: New Zealand Status: Offline Posts: 6815 |
Post Options Quote Reply Posted: 29 February 2008 at 21:15 | ||
Thanks- I'm really trying to touch on the main points as a lot of these issues would merit threads of their own! Macro-photography can be a lot of fun, as often you don't have to travel far to find subjects. Also a lot of people like seeing the detail on small plants and animals they would not usually see. I tend to approach macro-photography with a great deal of enthusiasm and a little bit of science! Even so, there is a bit more to the genre than getting a good macro-lens and snapping away . |
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α1, α7cii- Voigtländer 15/4.5, 110/2.5 M; Zeiss Loxia- 21/2.8, 35/2, 50/2 & 85/2.4, Zeiss Batis- 85/1.8 & 135/2.8; Sony 24-105/4 & 100-400/4.5-5.6; Sigma 70/2.8 M; Sony 135/2.8 STF
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