Sunday 3 May 2020

Extension tubes, Raynox or dedicated macro lens, decision decisions


Welcome to my first photography blog 


After being encouraged, cajoulled, persuaded and nagged to start either a blog or online tuition during lock down I've finally succumbed to pressure. Please note that whilst I have 14 years experience, mostly at enthusiast level I do not consider myself an expert, I still have a lot to learn, but I am experienced in many genres, over the years I have chosen subjects to throw myself into and have pushed myself to produce the best work I could in each genre I have tried. I always learn new things from each genre which I can put into practice with my favourites - macro or portraiture. I do receive frequent requests for help with various photography projects so maybe this blog will offer a half way measure, demonstrating techniques, results, discussing an array of topics, maybe even  a sprinkling of inspiration. I wasn't sure what to start with, I have added a little background story all about me in a separate post prior to this. I love getting creative and do so mostly from home so hopefully a few of you will find some of my blogs useful or interesting whilst stuck at home during the pandemic, after that, well we will see...


I'm kicking off with some easy macro stuff, prepare to become addicted rapidly and end up with countless strange looks or embarrassing photos of yourself on the ground with your butt in the air trying to focus on weird and wonderful insects or plants and fungi.  I've lost count of the amount of times people have seen me lying on the ground near to my mobility scooter and they have thought I'd had a stroke :)



 I've been drawn to close up and macro photography since I was given my first DSLR, a Canon 300D as a Christmas present about 13 years ago . I had recently been diagnosed with M.E. and wasn't managing to leave home so my initial chosen subjects were the many plants in our vast garden and the exotic frogs and reptiles from my partners pet shop ( I also kept a few frogs as pets). I loved gardening ( pre M.E.) and also had a passion for herpetology ( reptiles and amphibians) so photographing both subjects was a natural choice for me, allowing me to really zoom in on the details and even discovering more about both topics. Lacking a macro lens to start with and I ended up buying a set of screw on macro filters to add to my 18-55 mm kit lens and this option certainly fuelled my growing interest. As a newby I was not in possession of specialist lighting and having no teaching I simply chose to use cheap table lamps to take my snaps at our dining table. I stuck my settings fully on manual within two weeks and threw myself into the deep end. So whilst many people are in a difficult position of being stuck at home during lock down I thought I would cover the topic of close up photography without a dedicated macro lens to start with. 




  I am using a Sony A7ii mirrorless camera and have chosen a lens that most photographers possess, a nifty fifty, you can try your kit lens if you don't own one. One of the cheapest and most widely available options to get up close in your subject is to use macro extension tubes which move the lens further away from the camera and closer to the subject. They connect as a lens does between the camera and lens and you can add several at once for extra magnification. There are calculations widely available on the internet and in books estimating just how much extra magnification your extension tubes will give you with each lens or explaining the minimal focal distance ( MFD), but I tend not to get keyed up about calculations and focal distances. However pairing extension tubes with different lenses will give you differing amounts of magnification. This is just a simple demonstration of what  I can achieve with a 50mm lens, compared against a Sony 90mm macro lens triggered by questions from my peers, many of whom are new to macro. I thought it might help them to decide whether to try out extension tubes, Raynox or aim for a dedicated macro lens. I will touch on macro filters as well. Note that all these options  when applied to your lens will stop your lenses ability to focus to infinity, you will only be able to focus on something close up - worth mentioning so that you dont assume your camera is broken when first using these.


All lenses are built to give optimal sharpness around certain focal distances that they are created to use most,  a macro lens will give its best results focusing close up at its minimal focusing distance, a telephoto lens can give optimum sharpness focusing a long way off. So applying a macro filter, extension tube or Raynox may result in images being less sharp than your lens produces when photographing what it is designed to photograph. They can produce some distortion and loss of fine detail even with the most expensive of lenses.

When choosing your extension tubes it is worth doing your research as some can result in you losing control over functions such as auto focus, meaning you have no choice than to manually focus. Look for tubes that will work with your lens. Some 3rd party tubes dont have any electric contacts so you wont even be able to change your aperture once mounted on your camera, so choose wisely.

When using your lens with extension tubes added you will notice a significant light loss, this is because by increasing the distance between sensor and lens you are effectively increasing the aperture. So your image gets darker and effective depth of field increases, although does not change on your cameras settings. See https://shuttermuse.com/what-is-aperture-in-photography/   for more details. Having said that you also lose depth of field when working in macro, getting closer to your subject can mean hardly any of it is actually in focus. So you may find yourself needing to increase ISO or decrease shutter speed to compensate for light loss.



The Raynox is a universal macro filter/adapter that snaps onto the end of your lens, unlike extension tubes it contains glass, which is how it achieves magnification. I will be using a Raynox 250. The Raynox gives higher magnification when used on a longer zoom lens, when coupled with a shorter lens such as a 50mm like I am doing initially it can result in a very shallow depth of field. I do not own a zoom lens to demonstrate this, although I may borrow one and add to this with a part 2. But you can tell a difference in the magnification between the 50 and 90mm lenses when the Raynox is applied ( see further down in comparison images )



Macro filters are screw on filters ( like a UV filter) with glass that is slightly curved, effectively bending the light, enlarging what you see, acting much like a magnifying glass. You can often buy these in sets of different sizes and they can be stacked, allowing you to use several at once. These filters can be quite  cheap, so they are useful in helping you decide if you enjoy macro photography.  The filters work by altering your minimal focal distance (MFD) - all lenses have an MFD - this is the closest distance your camera can focus on. If your lens normally has a MFD of 1 meter and you add a +2 macro filter you change the MFD of this lens to 0.3. There are complicated calculations which help you determine MFDs but I dont get worked up about these. The higher the number on your filter the closer it will allow your lenses MFD, stack them and they get you closer. However there comes a point, especially on a longer lens where adding macro filters can  adjust your MFD to literally immediately in front of your lens which blocks most of your light, or even adjusting it to inside your lens!!! I have not used macro filters in my comparison images here as I no longer own a set that fits my camera, but felt it important to include a bit about them.


There are down sides to macro filters and some of these also apply to the Raynox to some degree. A dedicated macro lens is expensive for a reason, it has specially developed  glass and modifications to help reduce any optical imperfections, giving you a lovely sharp result. Filters can give you a less  image sharpness and you can experience softness around the edges of your image. Filters are  known to produce problems like chromatic aberration, this happens more around the edges and can be more prominent when working with high contrast light. Look for filters made from metal and glass, not plastic. You will need to buy filters to fit each individual lens, based upon the thread size of your lens ( often printed on the end of your lens). Good points re the filters - they're cheap, convenient, pocket sized and allow closer shots of your subject for a fraction of the price of a macro lens and you can auto focus with them unlike some extension tubes.



The images above are of a common subject that is available right now in May in the UK anyway, even if you are self isolating you can probably find a dandelion on a grass verge nearby outside. ( Beware legislation on picking wildflowers though, whilst dandelions are considered weeds by most of us it can be illegal to pick particular flowers from the wild or even grass verges, such as council planted flowers).  Doing macro work makes you notice little things that you never would normally as shown in these images. I didn't know the seeds push the dying yellow petals out of the way, it seems to happen over just a couple of days, or it has in my home. I've found it quite fascinating. I have a tendency to collect various seed heads for macro photography purposes. Dandelion seed heads are incredible photogenic - look our for Salsify seed heads in a few months - like a huge dandelion.



This set of images below are all set at F18 on the same subject, starting with just the 50mm lens and no macro options, adding in 26mm of extension tubes,  then comparing against the Raynox 250 on the 50mm lens and finally using the lens with both extension tubes and Raynox. After this I followed the same sequence using a Sony 90mm lens and placed them side by side to give you an idea of the differences. 



I will let you draw your own conclusions on which combination of the above that you prefer. Personally I find the Raynox has given less clarity away from the focal point which is the centre of the flower, and it can also cause some vignetting, which is seen when using the Raynox alone with both lenses - but only when wide open at F2.8, it does not occur at F18.

Pros and cons  of Macro filters
Pros 
-Cheaper than a macro lens
Lightweight & compact
Can be used with most lenses
Stackable providing extra magnification
No need to remove lens when adding or removing

Cons
Sometimes loss of quality or sharpness
Possible chromatic aberration & other distortions
Your lens cannot focus to infinity with macro filters added
Lets less light into your sensor

Pros and Cons of macro extension tubes
Pros
Cheaper than a macro lens
Lightweight & compact
Can be used with most lenses
Usually minimal loss in quality due to no  optical elements
Stackable providing more magnification


Cons
Your lens cannot focus to infinity with the extension tubes added
Can  result in vignetting
Can reduce light / increase effective F stop requiring compensatory actions
Having to remove your lens each time you wish to add or remove a tube on location can increase the chances of introducing sensor dust especially on location


 A few things to keep in mind if you are new to macro photography. The closer you are to your subject the more light you might block from reaching your subject. So whilst using a 50 mm lens the flower was nicely lit, when I added extension tubes or Raynox I ended up closer to the flower and had to increase my light or my ISO to achieve the same light exposure. Again when I added both I was even closer so again had to adjust light, however its not just about adjusting the power of any lights, you may need to adjust the positioning too as it can be hard placing lights in front of your subject if that's where you are and there is little room.  This is why many macro photographers use on camera flash, flash rings or other specialist macro lighting. I favour off camera flash, which is conveniently permanently set up in our dining room to save me energy. 


With macro photography you will soon start to notice that you lose a lot of depth of field when you are close up to your subject, so you may find yourself shooting up to F 18 and still getting only a slither of your subject in focus. I find using lighting to kind of model your subject ( where possible) can sort of enhance your depth of field, making it appear better than it is, especially with a little side lighting or back lighting. 


Losing depth of field can even enhance your imagery if used creatively, sometimes offering an abstract view. I found that by  opening up my aperture to F 1.8 or F 2 with both the Raynox and extension tubes on with my 50 mm or Macro 90 mm lens gives me a wonderful ethereal dreamy effect with some flowers. As seen with this tulip and the following Anemone images. 

I hope to cover image stacking macro images at some point which can help with ensuring you do not lose depth of field when it is important that more of your subject remains in focus.


Another thing to consider when starting out with macro is keeping yourself still whilst taking your photo. You will find yourself balanced in silly, precarious positions whilst attempting to capture masterpieces, with utterly dreadful light at, which you make worse by blocking light. Your ISO can end up high, tempting you to use a slower shutter speed, so that you can retain a better depth of field. Using a tripod can be awkward, they're big and bulky, often too tall etc. There are mini tripods available to help you keep your settings as you prefer, also tripods whose legs can change directions and go almost flat allowing you to get close to the ground. I find a bean bag to lean in can help too.


You will find yourself holding your breath so that you don't move that millimetre, some suggest that you exhale slowly as you press the shutter rather than holding your breath. Pressing the shutter gently can be preferable to  a rapid press jarring and moving your camera. I will add more little tips to help your photography with other blogs.


Please feel free to comment on the blog and add any requests for future topics.


9 comments:

  1. Thanks Angi, a very interesting and informative read. I picked up some new knowledge and tips from it to, plus your images are beautiful as always...

    Paul :D

    ReplyDelete
  2. Great in-depth post Angi, full of information! :)

    ReplyDelete
  3. Great Blog and interesting reading!!

    ReplyDelete
  4. Great Blog Angi, clear, concise and easy to follow. Thank you for sharing I’m off to practice as you’ve inspired me.

    ReplyDelete

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