Since the evolution of digital photography, advancements in software development have seen many new techniques and workflow improvements become available. It is now possible with a few clicks of the mouse, to overcome many of the time-consuming processes and issues that were once challenging a few years ago. One of the biggest advances in macro photography is the ability to extend the depth of field by combining individual images using specialist software such as Helicon Focus and Zerne Stacker etc. Photoshop also allows you to do this, but it has limitations in what can be achieved. If this is a practice you are likely to do frequently then investing in one of the specialist software programs will be more efficient, faster and the end result will be much more consistent.
As a professional Natural History Photographer I have to cover many different subjects, but macro is one of my specialist fields of interest for the past 30 years. It is also an important part of my routine work especially in relation to some of the high-profile Natural History Projects I have worked on in Ireland and the UK. My interest in photography came about through my work on specific groups of insects, in particular butterflies, moths and dragonflies, which I have written about and studied for most of my life. However as a nature photographer I have diversified into other specialist fields, some of them involving a lot of close-up imagery.
The current advances in camera electronics and lens design, mean we have some pretty powerful equipment at our disposal. Used in combination with some of the latest software allows us to produce images that pre-digital was extremely challenging or in some cases almost impossible to achieve. One of the most important advances, from a macro photographer’s perspective, is being able to extend the depth of field. I find this practice invaluable in some of my specialist work for example lichens, fungi and plants.
FOCUS STACKING FUNDAMENTALS
Before proceeding to the main review, I think it’s important to have a basic understanding of focus stacking and some of the problems associated when applying this technique. Outlined below is a brief overview of the two approaches.
Focus Stacking, Focus Blending or Extended Depth of Field are terms used to describe the digital image processing technique. It is not a new concept and has been around, albeit in a more rudimentary form before the digital revolution. It was primarily used in the world of photomicroscopy and by museums. The word “focus stacking” is essentially a photographic term used to describe a series of images photographed at different focus distances which are combined to produce a final photograph that has a greater depth of field than any individual source image.
The collective images are then processed in a specialist piece of software that analyses and blends the in-focus areas within each image to form the final photograph. One of the advantages of applying the focus stacking technique is the fact that you can shoot at the lens’s sharpest aperture, or sweet spot while retaining maximum detail and contrast in the photograph. You can also photograph subjects from more oblique viewpoints; something that would have been difficult to achieve working in the normal conventional manner. Companies such as Helicon Focus and Zerene Stacker have made the whole process of focus stacking less complicated. Excellent results are achievable with having only a basic understanding of how the process works.
Combining images to achieve an increased depth of field is an amalgamation of two procedures. The first is capturing a series of photos, each taken at different focusing points to attain complete sharpness throughout the subject, or to a point of your choosing. The second is combining the images in an appropriate piece of software to produce a single composite photograph. Although it may seem a relatively straightforward process, there are pitfalls and issues to be aware of throughout the whole process.
There are basically two methods to focus stacking. The first, and probably the most widely practiced of the two, is, “Variable Focus Rotation”, changing the point of focus by rotating the focusing ring on the lens in small, incremental stops. This method can work reasonably well at lower magnifications and with experience it is possible to get acceptable results up to 1:1 (life-size) with some subjects. However, the problem with this technique is the inconsistency in the incremental movement between shots, although using a small aperture can help since the overlap in depth of field can compensate to a point at lower magnifications. The downside of this method is the risk of diffraction due to the selection of smaller apertures. In addition to this you are forced into using slower shutter speeds or raising the ISO to avoid them. Lenses generally have a sweet spot and apertures of between F/8 and F/11 are best to reduce the risk of diffraction.
Altering the focus point by hand with this approach becomes more of a problem as magnification increases. Rotating the focusing ring is actually changing the magnification slightly within each frame however, the software takes this into consideration during the stacking process. At higher magnifications, rotating, the focusing ring has virtually no effect, as the depth of field is so shallow. Movement imparted to the setup while rotating the focusing ring on the lens, can cause problems during the blending procedure in the software resulting, in digital artifacts and areas within the stack where there has been insufficient overlap in the depth of field, or slight movement in the camera setup; this is often visible in the diffused background of the composite.
The second method is ‘Manual Advancement’. In this case, you are changing the point of focus by moving the entire camera assembly in small, incremental movements. This is difficult to carry out precisely as you are making the adjustments by manual progression which can increase your chances of artifacts due to insufficient depth of field overlap in some images, particularly at higher magnifications. Some cheaper manufactured rails actually increase the likelihood of instability during the process. Manual Advancement is often used when working at higher magnifications however, both methods have pros and cons.
In some of the recent camera bodies, manufacturers have incorporated a focus stacking feature within some of their cameras utilizing the autofocus system to move the lens to different focus points as dictated by the parameters set by the photographer in the menu. However, this approach is of limited use in my opinion, and best suited to images captured at lower magnifications since you have no control of the autofocus during the stack sequence. It can also be a bit hit or miss in some situations, also the degree of focus overlap is limited compared to an automated rail; this becomes more apparent when photographing at higher magnifications. Focus stacking is best carried out with autofocus switched off where you have complete control of the whole process.
One of the advantages of using a motorized rail is continuity and precise incremental movement for each image and the increased stability which reduces many of the issues associated with a manual hands-on approach. This is just a brief overview of the focus stacking technique. You can refer to my latest macro photography publication for more information or the web which has many articles describing the procedure and the problems that can occur when using this method.
APPLYING THE TECHNIQUE
When to employ focus stacking is a difficult question to answer. it is not the solution for every image that lacks sufficient depth of field. If that were the case, we would end up with a series of photographs that are uniform in appearance and lacking in imagination and style. It should be used carefully and creatively in my opinion when the image would benefit from its application. It is not always necessary to have complete sharpness throughout for several reasons. For example, you may want to create an artistic interpretation and in this context, the choice of aperture and focal length of the lens are important and dictate how the final image will look. Also, photographing mobile subjects such as insects present a greater challenge when employing focus stacking. Trying to capture multiple images of a moving creature brings its own frustrations. In my own work, I use it when I think the subject will benefit from it, or when working at higher magnifications when sharpness throughout are the most important factors. I tend to be more selective with mobile subjects for reasons already stated, but there are situations with active creatures where it is possible to achieve an acceptable outcome.
Although focus stacking is an extremely useful technique, it also has some drawbacks. The implementation of the technique is an important part of the process. Achieving consistency in the stack sequence does require, in the vast majority of cases, working from a sturdy tripod to ensure continuity and consistency in the result. There are some photographers who claim they can work tripod-free and perhaps in a minority of cases it’s possible, but if you want to produce consistently high-quality images a tripod is the best approach in my opinion.
It is fair to say that static subjects tend to produce more successful stacks as the photographer has more time to execute the process carefully. Mobile creatures can be hit and miss, also movement caused by the wind can be just as frustrating. Shortcomings in any of these aspects can lead to increased artefacts and considerably more time spent in software trying to correct them. Another fact to consider is what may look fine for the web may be unsuitable at higher resolutions due to other artefacts, halos or the lack of sufficient focus overlap which can go unnoticed in a smaller image.
PREPARATION AND APPROACH
A successful stack relies on several factors no matter what method you employ. There is little point investing in a motorised rail system if the underlying support for it is poor. Below are some of the main points to bear in mind when compiling a composite image.
- Mount the camera and rail on a sturdy tripod to ensure stability and continuity in each image in terms of framing and precise focus. Avoid cheap, lightweight models. Novoflex have some excellent models with interchangeable legs which is useful.
- Switch your camera to manual, this will reduce the chances of any variation between each exposure.
- Change the white balance from auto to manual and set a specific colour temperature. You want to ensure continuity in the white balance throughout the exposure sequence otherwise any change in the light temperature could affect the colour balance.
- The light source is another important factor that needs to be considered carefully. When photographing outdoors, you want the natural light to remain constant during the stacking arrangement; any variation will result in slight differences in the exposure values of the images which will lead to artifacts in the final composite. Bright sunny days when cloud movements are constantly changing are to be avoided if possible. In challenging lighting conditions try were possible to select subjects in more shaded areas.
- Lens selection is also important. The majority of macro lenses are now capable of 1:1 (life-size). However, as you become more experienced and familiar with your technique, you may want to explore the possibility of photographing at higher magnifications. I will discuss this separately using the Castel-Micro and the advantages that a motorised rail can bring to your macro photography when moving into the realms of true Photomacrography.
Whether you focus stack using conventional methods such as ‘variable focus rotation’, or ‘focus rail advancement’. There are, of course difficulties and challenges to overcome, but also be prepared for failure with some subjects that do not lend themselves easily to the technique; there can be many reasons for this. Trying to photograph all of the images in a stack sequence under the same conditions, e.g. maintaining the correct aperture, shutter speed and white balance etc. throughout the procedure can be challenging . You may also be shooting in changing lighting conditions which may affect the final stack sequence. If the subject is static, e.g. a lichen or fungus, etc. then you have time to choose your moment, or where possible use a diffuser to keep the light falling on the subject even and consistent.
Compiling focus stacks of active subjects such as insects is much more challenging. As a conservationist, I don’t condone the practice of killing and mounting them on a platform to facilitate a photographer’s self-importance. I have had an interest in insects for 30 years which has helped me gain a better understanding of their behavior. It is possible to get some very good results with insects if you choose your time carefully and study their habits. Insects are cold-blood and therefore react to the ambient temperature. Photographing in the early morning when they are torpid is an excellent time as many species will remain inactive for quite a while in lower temperatures. However, it still can be, hit or miss irrespective of whatever technique you employ.
THE NOVOFLEX CASTEL-MICRO
Novoflex is a long-established company with a renowned reputation for innovation and the manufacture of high-quality photographic equipment. The company was founded in 1948 by a photographer called Karl Müller and started out by manufacturing reflex housings for Leica Rangefinder cameras. It is a highly regarded company, not only in Germany but throughout the photographic industry and in many ways occupies a similar niche in the European market as Really Right Stuff does in the USA. Over the years, the company has been the innovator of many photographic products, but its reputation for constructing a wide range of equipment and accessories for macro photography is well known.
Most of the current motorised rails (and there are not many) are used primarily in the commercial sector, mainly for product photography and at magnifications generally up to about 1:1. However, many other macro enthusiasts use motorised rails for extreme macro photography of insect specimens and flowers, which is usually carried out in a home-made studio setup.
My own interest in the Castel-Micro rail was to see if it could be used successfully in a natural history context, mainly out in the field and if so, could it be integrated into my workflow on some of the work and commissions I frequently undertake. Also, would the advantage of controlled and precise incremental movements of the lens produce cleaner, sharper stacks than my own current techniques. I also wanted to see if it could be set up quickly in the field and what subjects would the rail be ideally suited to. Many of the challenges with focus stacking apply whether you are doing it freehand or using a controlled unit. Another important aspect from my point of view was to see if using measured and precise movements were discernible at lower magnifications over conventional variable focus rotation.
WHY USE AN MOTORISED FOCUSING RAIL?
One of the most frequently asked questions by macro photographers to me is whether or not (considering the additional cost), a motorised focusing rail will make a significant difference and improve the composite stacks. The answer, without any hesitation, is yes and there are many advantages in doing so. Some of which are outlined below.
- Not having to manually touch the camera setup during the shooting sequence is a key factor. No matter how carefully you perform the procedure, you are still imparting some movement to the camera and rail while manually performing the task.
- Manually moving the camera for each shot is, without doubt a tedious task. Speed is one of the main benefits of using a motorised rail.
- Using a motorised rail eliminates the risk of movement, or vibration as a result of touching the setup during the shooting sequence.
- A motorised rail delivers a precise and measured incremental movement; something you cannot achieve when manually carrying out the procedure.
- A automated rail also reduces the risk of insufficient overlap between shots, causing protentional artifacts in the final composite.
- You can use wider apertures (maximising on the sweet spot of the lens) with a motorised rail reducing the need to employ longer shutter speeds and increased ISO settings therefore lessening you chance of diffraction.
- Where a motorised rail really comes into its own is when you are photographing subjects at magnifications approaching and greater than 1:1. Magnifications above life-size is where many problems can occur when working manually. Rotating the focusing ring at these magnifications has little to no effect. Resorting to a motorised rail makes it possible to get consistently good results. When used in combination with other specialised macro lenses it introduces you to a whole new world of subject material to explore at magnifications higher than conventional macro lenses can deliver.
- One of the most compelling reasons for using a motorised rail is being able to use wider apertures to reduce the risk of diffraction from stopping the lens down to gain extra depth of field. Using apertures outside the lenses diffraction zone reduces the risk of loss of sharpness and contrast
- Controlled focus stacking also allows you to obtain the exact depth of field you require using the optimum apertures.
INITIAL OBSERVATIONS WITH THE CASTEL-MICRO
My first impression of the rail was one of a well-designed, engineered unit; I would, however, expect no less from Novoflex on this front. It was naturally colour coordinated as are all of their products making it easy to identify the brand. To be honest, most of the other rails currently on the market remind me of prototypes rather than completed units; I’m not questioning their capabilities, in terms of performing the task, but on observation, they seem unfinished and may be more suited for studio work since more of their components and structure are exposed, not so with the Novoflex rail; this is just an observation on my part!
The Castel-Micro comes packed inside a high-quality zipped case, which contains all of the components. The motorised unit is encased inside a sealed metal housing at the rear of the rail and therefore well protected; this leaves very few components exposed to the elements. The rail is not heavy but solid in its construction, which is ideal for fieldwork considering what the average nature photographer carries in a backpack. Included in the case is the control unit, mains adapter and a standard ethernet cable for connection between the rail and control unit.
Depending on which camera brand you use, the rail requires the appropriate connection cable between the camera and the control unit; Novoflex can also supply this. The rail can be used with any quick release system, but comes with the Arca Swiss style Q-Mount for the rail and camera mount as standard. The Q-plates for the Q-Mount come in different sizes, with or without anti-twist pins. The rail also allows for positioning the Q-Mount in a horizontal, or linear position if using a long focal length macro and depending on whether your lens has a tripod collar or not! You can also mount the rail directly unto the tripod head if it has an Arca Swiss clamp which in my opinion is a bonus eliminating the need for another mount between rail and tripod head. The enclosed instruction manual (unlike many), is well written and easy to follow.
The Castel-Micro has a maximum travel distance of 100mm (3.94 in) and a minimum repeatable stepping distance of 0.2 µ. Its vertical load is a maximum of 4 kg (8.8 lbs). Connection of the rail and control unit is quick and simple. Using the Castel-Micro in the field requires, if you are not a Canon shooter, to invest in a couple of Canon LP-E6 batteries and a charger, this gives you the freedom to use the rail independently from a mains connection.
Diagram of main and component parts of the rail
CONNECTION OF THE CAMERA TO THE RAIL AND CONTROL UNIT
The connection of the camera to the rail is best achieved using a quick release system. I would suggest the Arca Swiss, which has a good reputation. Ensure that camera it is correctly engaged in the clamp profile. Connect your dedicated camera cable to the focusing rack. The control unit is connected via an ethernet cable which is provided; this is to communicate the information to the rail. If using it in a studio setting then the connection is via the mains adapter, but for outdoor use then an LP-E6 battery is required. There is a battery charge status indicator in the calibration and stacking menu, but no facility for charging within the control unit; an external charger is required. The control unit has the facility for two batteries and automatically switches to the second battery when the first is depleted!
OPERATION OF THE RAIL
Each time you switch the unit on it performs a calibration test. You are required to keep your finger depressed on the button until this process is complete; a tick becomes visible when finished! During the calibration process, the sliding block returns to the top of the rail were it makes contact with a sensor. It does this each time you start the control unit up; this is the means by which the rail communicates its position with the control box.
When complete the rail is now ready for use and the screen will display the four modes. These are Stepp, Picture, Continuous and Bellows Mode. In this overview, I will be discussing the first two modes, which are the most useful for studio and fieldwork. Continuous Mode is essentially for scientific use and not relevant to focus stacking in the field. The Bellows Mode was developed for the bellows attachment (Castbal-Pro), which is used mainly in the commercial world of product photography. Note, this mode can only be used when the bellows unit is attached! In all of the modes you will have to enter shutter speed, delay, and also a start and end position, in other words, where your focus point starts and where you want it to end! I will give a brief overview of the first two modes.
THE CONTROL UNIT & MENU MODES
First of all, position your rail and camera close to the focus point of your first image. Whichever mode is selected, you have to determine the start and end positions of the stack. The three menus are arranged in order to expedite the process. First, the camera settings, followed by the settings and stacking menus. Novoflex has laid the sequence out very clearly in their instruction booklet. I will give a brief outline below of the procedure.
When selecting your start and end position I found it better to extend a little before and beyond your point of final focus. When on-screen you can then select exactly where you want to commence and end the stack!
- DELAY: Depress the blue field and enter the delay between exposures you want. I found 1 second perfectly adequate in most situations.
- MIRROR UP: If this is ticked you must activate it on the camera as a pulse from the control unit is sent to the camera before triggering the shutter. If your camera has the Live-View then use this and do not tick mirror up?
- SHUTTER SPEED: Enter the shutter speed as indicated on the camera for the correct exposure. The unit needs to calculate the waiting times between exposures based on your selected shutter speed.
- DELAY MIRROR UP: This only appears if the “Mirror up” has been activated. If using Live-View, which I recommend then it remains inactive.
- LOAD SETTINGS: You can recall previously saved configurations if you wish.
Depending on the Mode selected proceed to the Settings Menu and complete the following:
Step Mode & Settings Menu
START: Press the start field and move the slide block to where you want the stack to begin. Do this by hitting the left and right arrows beside step mode at the bottom of the menu. Once complete, depress the start button again and it turns grey.
END: Select the end field and it turns blue and fast forward to the end position of where you want the stack to finish. Depress the button again and it turns grey.
STEP IN MM: Since you are specifying the step length in mm which can be read below the end field, the unit automatically calculates the step size which is indicated in the dark blue field. The steps are then calculated and the number of shots required. The step length should be less than the depth of field. You ideally only want to use only a small part of the depth of field to ensure you have sufficient overlap between shots. The easiest way to calculate this is take the step length and divide it by 4 and enter it into the “Step in millimetres”, this will recalculate the number of shots needed. Although this may seem complicated, experimenting is the key and very quickly you get to know the ideal setting for the magnification you are employing. You can alter the step value by pressing the blue button and the number of shots will increase or decrease depending on what value you enter.
COUNTDOWN: Once you have completed the information in the settings menu you can proceed to the Stacking menu. Here you can set a delay using the countdown field if you wish. For example if you think there could be a vibration and you want time to stay clear from the main area then the shooting sequence will only commence when the delay is complete.
SAVE SETTINGS: Use this field to save the basic setting so it can be used again if you wish.
GREEN PLAY BUTTON: Press the green button and the stacking process with commence. The sliding block with the camera will move back to the start of the front focus position and start the sequence.
RED BUTTON: Use this to cancel the running stack if necessary. It will retain the current settings. Pressing the green button again starts a new stack.
POS: Located in top right section of the display window, it shows the current position.
DELAY: Counts down in seconds.
NUMBER OF SHOTS: A countdown to zero from the designated number of shots so you can see exactly where it is in the sequence.
DURATION: Time that will be need to complete the stack.
BATTERY WARNING ICON: Displays current charge left in the battery. It will switch automatically to the second battery when depleted.
If you want to repeat the stack or make changes in the Camera Settings or main menu press the blue rotary knob.
If Picture Mode is selected, all of the other parameters as in Step Mode apply. However, in this case, you are specifying the number of shots you may need e.g. 100. The Step Length is automatically calculated and displayed under Step number in mm, e.g. 0.1563. In this case, you are specifying the number of shots rather than changing the Step value, which affects the number of shots needed.
USING THE FOCUSING RAIL IN THE FIELD
To familiarise yourself with the workings of the rail and to gain an understanding of the different modes, It is a good idea to do some initial experiments in a studio setting before using the rail in the field. The software is cleverly designed, so it does not take long to grasp the main principles of how it works. I found the ‘Step Mode’ useful in the majority of my situations but, the ‘Picture Mode’ also works equally well especially when speed is of the essence.
Setting up the rail in the field takes only a few moments. I made a couple of modifications to the inside of my photographic back pack and attached the camera directly to the rail to save time taking it on and off. The rail and camera are then mounted directly unto the Q-clamp on the Classic Ball 5 II head, leaving me only to connect the camera cable.
Once the image had been composed using Live-View and the subject in focus, switch on the control unit. It performs a quick calibration check (which only takes a few moments), and the rail is operational. Select the mode of your choice for example ‘Step Mode’. The quickest method I found is to defocus the subject a little by rotating the focus ring. Activate the start button and advance the rail to the first point of focus. Follow the steps as indicated in the menu section above.
At this point you can refer to the guide table in the instruction booklet, or make an adjustment in the step field yourself to ensure you have enough overlap between each shot. I have found that for magnifications up to life-size a value of 0.01-0.05mm is a good starting point and using an aperture of between f/8 occasionally f/11. You can see the number of shots increase or decrease depending on the step adjustment. Advance to the Stacking Menu and hit the green arrow. The unit block will then return to the first point of focus and commence the sequence of shots.
One of the real advantages of using the rail for the majority of your focusing stacking subjects is the fact that you do not have to manually touch the lens or camera therefore eliminating the risk of vibration. You may think this is insignificant at lower magnifications, but there is a difference in the quality of the final result in my opinion. Also, if you want to achieve high quality images at much greater magnifications then this is where a motorised rail will take your macro photography to another level. In fact, you can wonder off looking around for other subjects while it does its business. The unit has the facility for two batteries. If you plan on using it a lot in the field you will need two batteries as one will not be sufficient to sustain continual use over a full days shooting.
You can of course use any lens of your choosing on the focusing rail, but in my experience working with a dedicated macro is by far the best option. Macro’s lenses around 100mm are ideal. These are reasonably light and most are capable of producing magnifications up to 1:1. I use Nikon so I tested the 105 and 200mm micro nikkor’s. Both lenses performed extremely well and there were no issues. I also experimented with Nikon’s AF-S TC-20E-III converter in combination with the Nikon 105mm macro. The results were extremely good increasing the protentional to produce images up to twice life-size for those that do not own a higher magnification macro lens! Operating at these magnifications in the field can be challenging but using the Castel-Micro in preference to a manual rail is a game-changer in these situations.
MAGNIFICATIONS BEYOND 2:1
Working at magnifications beyond twice life-size raises many more challenges; vibration, or slightest movement of the camera can compromise the final outcome. Also, reduced depth of field at level makes it more difficult to achieve consistently acceptable results especially when working outdoors. The variable focus technique is ineffective beyond 1:1. Achieving much higher magnifications in the field are of course possible. However the same principles apply whether you are shooting with a rail or not. Weather is a key factor. Trying to achieve perfect stacks when the wind is blowing isn’t really going to work. You also want to shoot your stacks in stable lighting situations to avoid exposure changes. Subject selection is also important; not everything is not ideally suited to focus stacking in the field. Mobile subjects are naturally challenging to do successfully even when conditions are perfect.
Photographing at much greater magnifications is where the Castel-Micro excels. Used in combination with a higher reproduction macro lenses is where you begin to see results which are far more challenging to achieve using a manual setup. For magnifications greater than 1:1, I use the Nikon micro nikkor 105mm in combination with the 2X AF-S TC-20E-III. Magnifications above 2X I switch to the Laowa 15mm 2:5-5x macro; I already had this lens as part of my kit. It is small, extremely light and easily carried. Being a manual focus lens and diaphragm macro is no disadvantage when working at higher magnifications since you can switch to Live-View which makes the process much easier.
Being able to shoot a up to five times life-size does open up many new possibilities with tiny subjects in the field. The results with this lens are impressive and it is my routine combination
Lens reversal, is another approach and Novoflex do make an automated Reverse Adapter for many of the leading camera brands. The adapter retains all of the automatic functions of the lens allowing you to gain additional magnification if you do not own a macro lens. Zoom lenses work well in these situations to a point. Other approaches included placing another lens in front of the primary lens. Raynox make a range of macro conversion lenses which produce reasonable results.
Over the last few years some independent lens manufactures have produced specialised macro lenses. Canon is the only major camera brand to have a macro lens capable of going beyond 1:1. The Canon MP-E65mm 1-5x macro is a manual focus lens. Venus Optics, a Chinese lens manufacturer has developed several innovative macro lenses under the brand name of Laowa. Their 100mm f/2.8 2X Ultra and the 25mmf/2.8 2.5-5x Ultra Macros both are manual focus and produce outstanding results especially when used on a motorised rail. Both lenses are very reasonably priced compared to the Canon and offer the macro photographer the chance to explore subjects at greater magnifications; something that the majority of major camera manufactures have sadly neglected in their lens lineup!
There is no doubt the Castel-Micro is a well-designed piece of professional equipment. It’s apparent from the overall design of the unit that some thought has gone into its fabrication and ease of use. Although it may have been developed initially to meet the needs of the commercial sector; primarily in a studio environment, its versatility when used out in the field is equally impressive.
Once you become familiar with setting modes, using the Castel-Micro in the field is straightforward. The stack sequence is quick since the rail does the work for you. I also found myself using the rail frequently on subjects at lower magnifications where I would normally have used variable focus rotation in the past. Even at lower magnifications, the results were consistently better and with fewer artifacts.
Entering the realms of true macro photography (beyond 1:1) is where you begin to see the real advantage of using the Castel-Micro focusing rail for many of the reasons already stated. It eliminates much of the guesswork and the results are consistent; something that is hard to achieve routinely with a manual approach especially at higher magnifications. I am impressed with the Castel-Micro and its ease of use in the field. It has, in many ways, exceeded my expectations. Specialized equipment is never cheap, but if you plan on doing a lot of macro photography and are serious about the work you do then having a motorized rail as part of your photographic kit is an absolute must in my opinion.
I would like to thank Martin Grahl sales manager at Novoflex in Germany for his help in answering many of the queries I had during the testing of the equipment.
Further information on the Castel-Micro and Novoflex can be obtained through the following distributors listed below. Visit www.novoflex.de for worldwide distribution in other countries.
NOVOFLEX Präzisionstechnik GmbH Brahmsstr. 7 D-87700 Memmingen Germany Tel.: +49 8331 88888 Fax: +49 8331 47174 Email: email@example.com
Speed Graphic Mail Order LtdUnit 9A Oakhanger Farm Business ParkOakhangerBORDONGU35 9JATel:01420 560066From outside the UK +44 1420 560066
Red Raven Marketing74 Marietta St. Uxbridge, Ontario L9P 1J5Tel: +1 905 852 4106 Fax: +1 905 852 4106Email: info [at] redravenphoto.comwww.redravenphoto.com
MAC Group 75 Virginia Road North White PlainsNY 10603Tel: +1 914 347 3300 Fax: +1 914 347 3309Email: info [at] macgroupus.comwww.macgroupus.com