Vices and virtues of extension tubes

Before buying a set of extension tubes, I have done my homework but I did not find so easily the information I was looking for. This article intends to answer the questions unresolved before I decided to buy them despite some grey zones. The main questions were the following:

– What can we expect from them?
– Who are the manufacturers and why chose one rather another?
– Advantages and constraints of extension tubes,
– Comparison with teleconverters,
– Real life feedback.

I have written my tests and conclusions into a pdf document “Extension tubes“, the analysis was too long to be posted as a blog entry. I have indeed read several articles, translated some which where not written in English and made my own tests.

And I came to several interesting conclusions:


Extension tubes don’t really work with wide-angle, that’s too bad, and it means you need a fish-eye when you want both a wide-angle and a very close focus (indeed some fish-eye can really focus as close a few centimetres from the front lens).

Extension tubes are not for beginners. For those on a budget, they are options not more expensive and more versatile (short focal macro lens, used if necessary).

Extension tubes work actually very well with long focal lenses (above 100 mm typically) either with macro lenses to get even closer, or with non macro lenses to shoot action macro, with reproduction ratio around 1:2 and not 1:1, fair enough but at f/2.8 if not f/2.0 when used with fast lenses.

Plastic made extension tubes (most of them) are not rigid, and therefore not really done for real reproduction purposes. However, when handling the camera with one hand and the lens with the other, they are still usable with heavy lens (at least as heavy as 2 kg).

The final word

Extension tubes are great accessories, not so expensive, but not versatile and only useful in specific conditions. I recommend buying a set and trying them to understand how each photographer can use them the best way possible for their photographies.


Here above the comparison of a 35 mm DX, the same lens with the whole set of tubes, and a 105 macro with the whole set of tubes. You will find more examples in my pdf document “Extension tubes“.

A genuine test of the underwater WP-DC43 Case for Camera Canon S100

I have bought the Canon S100 as a second camera (a Nikon DSLR is my main camera) and I like the idea to protect it to depths of up to 40m with the optional WP-DC43 waterproof case.

Indeed, whereas you can find a lot of underwater point-and-shoot cameras, none so far can shoot raw, and their sensors, even for the best (Panasonic DMC-TS4), are no match to the S100. Conversely, the cameras with better sensor usually propose underwater case at a price far higher, and are usually much bigger and heavier.

So the S100 + WP-DC43 looked to me like a nice compromise: not cheap but not too expensive for a full manual-raw camera with a great (small) sensor, a small and light body, and very capable of taking great pictures.

Whereas I have not yet dived with both, I have made my first tests, and I have been struggling finding online reviews from users. So these are my first impressions, which are, so far, the only genuine ones as far as I know:

I like: many details are making it “almost” professional: light diffuser for the flash (works quite well if you are not in macro mode and remember that the S100 flash is not exactly the best for its class), you can use a tripod. It’s easy to put the S100 inside the case and to remove it. The leash works quite well too. Last and of course not least: easy to handle, controls and buttons can be used with gloves, it’s really easy to use it in the case. It is even somewhere easier than without!

Issues: you cannot use any longer the rear wheel! You can still use the front one however. So basically, the S100 is not as seamless to use manually as without the case, but you can still have full control. It is an issue you can live with, but that’s a real one. Further more, there is no cap for the front window of the case, that’s really too bad. And there is no bag either for the case itself. One made in neoprene would have made sense. The light diffuser’s leash cannot be attached to the body without some additional small carabiner (not included of course). The buoyancy of the case and the camera altogether is really positive, you really need to add some weight to make it neutral. Of course it is written nowhere in the S100 mini-website (or show me where please), but you can purchase the weights (Canon WWDC1, image on the left), actually you really need them for diving.

Image quality for underwater pictures: remember, the S100 can shoot RAW, has some very nice low light capabilities and can open at f/2.0 at 24 mm, but cannot be synchronized with additional flash but the small one embedded. Please also note than the sensor is still quite small even if bigger than most of the point and shoot. Therefore, the depth of field is really significant, often too much. Conversely, in macro mode, that’s making the shooting straightforward compare with APS-C or FX sensors.

An extreme shot, close to some dangerous wildlife, WB auto, no flash, low light.

Conclusion: the S100 and its underwater case are not cheap, but they are a very decent option to take serious underwater pictures, for the fraction of the price of a DSLR and its 40 meters depth underwater case. However, they are issues and limitations, which could not be negligible for some, but which I believe to acceptable, even if regrettable for most of them.

Everything about the Nikon AF-S Teleconverter TC-20E III

I know the stuff has not been released recently (released around 2009) but when I was interested in purchasing one, it has been quite challenging to make a decent opinion about it. So let’s make a summarize:

To make a long story short: it works pretty well for a x2 teleconverter but it is a x2 teleconverter which means: you can use it but the image quality is not as good as without it and the loss of 2 stops cannot be negligible. The AF works quite well as long as you are using a fast lens, as one could understand, AF does not work well for lens slower than f/5.6. So if you need it, you can buy it, again it works quite well. But if you can afford buying the big and expenses Pro tele-lenses, that’s better, but very expensive and very heavy too.

I can basically identify 3 main reasons to buy it:

  1. With the 70-200 VRII f/2.8 to get a 400 mm tele-zoom, decently opened (f/5.6) and not too heavy,
  2. With a long pro tele-lens (400 mm f/2.8) because, well, if you need a bigger gun you need a bigger gun,
  3. With the 105 mm Micro f/2.8 because you can increase the macro capability significantly, and because some bugs don’t allow you to come closer and the 200 mm f/4 is quite expensive, especially if you already have the 105 mm.

You should remember that the teleconverter is not cheap, and is heavy. Another option, which I find to be consistent, is to acquire the Kenko Teleplus PRO300 2x DGX for half the price of the Nikon and which weights less. The image quality is not as good but looks decent (I have only the Nikon) and as Teleconverter are nothing but a compromise, it is making sense to avoid spending too much. If you don’t like compromise, you should buy the lens you need and don’t use a teleconverter at all (but if you want very long focals, like a  800 mm, fair enough).

Last and not least, teleconverters don’t work with every lenses, so check the list before.

Additional resources:

A few more pictures from the field:

Do you really need a better camera? Episode 4: everyday life

I am comparing a DSLR and a compact, both modern and famous for their excellent quality images (Nikon D7000, Canon S100), in order to evaluate when we really need to get one or the other, or both together. Sometimes, I am also comparing the pictures with those taken by a smartphone (Samsung Galaxy SII).  I am also doing this as I have noticed this kind of comparison is seldom done. Most of the time, people are comparing cameras of the same kind but don’t ask themselves whether they really need this category of camera. Previously, I have noticed that outdoor/landscapes shots during the day may not really require the big and fat DSLR. I mean I have been surprised by the performances of modern tiny sensors as soon as there is enough light. However, I have also noticed that for Macro, the DSLR was still much better.

So now let’s come to a very basic kind of pictures: portraits done inside. Everybody is taking some, of friends, family, … I have chose to shoot at the end of the afternoon, my little baby, either when she was playing, or in the arms of her mother but with back to the light. These two kind of pictures are actually technically quite challenging for the cameras, and this time, again, thanks God, the DSLR is again much better, as expected:

The very compact camera cannot be fast at 120mm equivalent (f/5.9). I had to shoot at 1600 ISO, and the speed was from far too slow (1/8 s). The stabilization does not help so much as a baby is not always standing still.

With a modern DSLR and a fast zoom (70-200 VRII f/2.8), everything works as expected, thanks God. This gear (body + zoom) is 8 times more expensive and 10 times heavier than the compact!

With back light, the light evaluation was not as good with the compact than with the DSLR. Further more, I had to shoot at 3200 ISO and whereas the speed was almost fast enough, the back light underexposed it so much I had to post-process the RAW to get an acceptable picture. But the noise is pretty much unacceptable! Last and not least, you can compare the depth of field (DOF). f/5.9 and a small sensor is making more or less any picture with too often too much  DOF.

With the DSLR, the picture is not perfect. The back light made the picture under exposed too but the post processing of the RAW file is providing a much more acceptable results. The speed (1/125 s) was what I wanted (I respected the rule 1/f equivalent FX) and the DOF is much more adequate too.

Comparing the grain of both cameras, after applying some noise reduction during the post process, the difference is not obvious, which mean that you should more take care of the dynamic of the sensor than just the MP (which is a little bit a surprise to me by the way). That said, difference between the two sensors is not that big (12 MP and 16 MP):

(Canon S100, crop 1:1)

(Nikon D7000, crop 1:1)


To make a long story short, there is still room to improve compact cameras for what they are supposed to be good at: family pictures. Whereas not liked by many photographers, and whereas I am still waiting for a Nikon mirrorless which I could use, you can understand the “raison d’être” of the Nikon 1 bodies: a fast autofocus and a much better sensor than compact can provide decent family pictures, which a high end compact camera like the S100 still cannot do really so often.

Do you really need a better camera? Episode 3: macro

So I am continuing my genuine tests between the best pockable compact (Canon S100) and a good DX DSLR (Nikon D7000). Basically, the idea is to understand much better when to use the tiny camera and when the big guy is really demanded:

During the last two episodes, here and here, I have been quite naughty with the great D7000. But as a matter of fact, for still daylight pictures, the small S100 is just a match whatever you are using with the DSLR.

So to go a little bit further, this time I tried to compare macro’s performance of the two beasts. I am using the Nikkor 105mm VR f/2.8 + D7000 versus the small S100.

This time, the clear winner (Yeah, good to spend so much money and carry such an heavy camera) is the DSLR! I took pictures with the S100 at 24 mm equivalent and 120 mm equivalent at the closest range possible.

Apart from a much longer distance to the subject, the macro lens of the DSLR can provide a 1:1 picture, which really makes a difference.

On a side note, the DOF is really bigger with the small sensor of the S100. Both an advantage (Easier to focuse well a picture) and a constraint (some, like me, are enjoying a reduced DOF).

So, to summarize, a compact camera can make some decent close range shots, but cannot compete anywhere with a DSLR… If you know compact cameras which can, please let me know!

Do you really need a better camera: Episode 2 – Landscapes (again)

In the episode 1, I have been surprised to have excellent pictures from a compact camera (Canon S100) compare with an excellent DSLR (Nikon D7000). Of course, I did not push them to their limits, that was not the point. I just wanted to check how a light and small high-end compact could replace efficiently a DSLR either as a second camera or for shooting which don’t required the performances of a DSLR in low light or fast autofocus. So just to be sure, I did additional tests, first at 24 mm (equivalent full frame) with three cameras: a Galaxy SII, the S100 and the D7000. Then with just the last two of them at 50 mm and 120 mm. The 35mm f/1.8 (equivalent 52 mm) of the D7000 has the reputation to be quite sharp and for the 120 mm, I used a 70-200 VRII f/2.8, not a cheap lens! I would assume much better results with the DSLR + great lenses compare with the high-end compact. But again, the tests are saying something different.

At 24mm:

Two pictures taken with the S100 at f/2.0 and f/2.8:

Obviously, the Nikon D7000 does not really provide better image (you can click on the images to see them at their actual size). And again, the smartphone may be smart, but is nowhere a camera able to challenge the two others!

Crop images:

Galaxy SII

Canon S100 – 24 f/2.0

Canon S100 f/2.8

Nikon D7000+Tokina 11-16 at 16mm f/2.8

At f/2.8, the Canon can show much more details and better contrast but, again, I am finding the Tokina and the D7000 somewhat disappointing compare with their tiny and much cheaper competitor…

At 50 mm:

Crop images:

Canon S100 – 50 mm f/4.0

Nikon D7000 + Nikkor DX 35mm f/1.8 at f/4.0

OK the Nikon and the Nikkor will show more details but the difference is nowhere dramatic as we should have expected. We are comparing a fixed lens and a APS-C camera with a compact zoom!

At 120 mm:

Crop images:

Canon S100 at 120 mm f/5.9

Nikon D7000 + Nikkor 70-200 f/2.8 VRII at 120 mm f/2.8

Nikon D7000 + Nikkor 70-200 f/2.8 VRII at 120 mm f/5.6

At f/5.6, the difference is now significant, but certainly not at full aperture of the Nikon! I know, the AF of the small S100 and the DOF cannot be compared with an APS-C DSLR and a pro zoom but to make a long story short:

The S100 is a real option as a 2nd camera during a shooting in “normal conditions”, i.e. without low lights and the necessity to have a very fast AF. Of course, the DOF of two cameras are very different and one cannot make same pictures with both. I don’t believe – regarding DXO tests, that the S100 is the only camera able to perform this way. I just think that modern compact cameras can now really be excellent cameras for serious shooters, even if they may not look like pro cameras!

Do you really need a better camera? – Episode 1: landscapes

The cameras’ manufacturers like when we spend money on their new jewels. Of course we can satisfy our desire for consuming and we can just waste our money. It has the reputation to help against being depressive! Fair enough, but I have always been wondering whether technical improvements were so useful and conversely, I am always wondering which camera do I really need for a shooting?

I am genuinely testing very different cameras : a smartphone, a compact camera and a great DSLR with its sharpest ultra-wide zoon :

Samsung Galaxy 2 (cost and weight virtually nothing as embedded into a phone)
Canon S100 (370 €, 200 g)
Nikon D7000 + Tokina 11-16 f/2.8 (1’700 €, 1’300 g)

The idea is to illustrate thanks to different tests which advantage has each camera based on real life pictures. I don’t intend to make any scientific tests there, just to ponder the necessity of bringing with me a heavy camera (The D7000), or even the necessity to buy or not a compact given the improvements of smartphones’ cameras.

The first test will be very trivial : a landscape, on daylight, still subjects. So I could compare sharpness, contrast, colours, … but I decided to just focus at sharpness on this first test.

Similarly, I compare on purpose JPG and not RAW as I would expect the best camera to provide better JPG too. I have worked with A mode (Aperture priority), and wanted to keep the cameras at f/2,8. That’s indeed the fastest possibility of my Tokina 11-16 and again I would expect given the price, weight and size better results at full aperture with the best camera.

So to make a long story short, I was assuming that at this aperture, the Tokina 11-16 and the D7000 altogether – given the reputation they both have, should be much better than the Canon S100 (and of course of the cheap camera of a one-year-old smartphone!).

First the three pictures :

You may not see it on the web, but you can click on each picture to see them as full scale and on my screen (1900×1200), the Galaxy 2 picture has some visible noise, without making any crop. Given the easy shooting condition, I am disappointed. I am sure newest cameras’ smartphones may be better, but I am sticking to my conclusion : you can shoot with smartphone, but the gap is still immense compare with more serious cameras. Looks trivial, but I am now sure !

Then I cropped at 100 % the D7000 and the S100 :

S100 crop at 100%

D7000 crop at 100%

The D7000 and the Tokina are far from showing more details than the tiny S100, that’s more the other way around ! That was a surprise for me. I don’t want to say the D7000 don’t overcome the S100 in many ways but as a matter a fact, for landscapes done at daylight, I may challenge the reason to carry a so heavy camera ! Nowadays, high end compact cameras have really become extremely capable… OK I need more similar tests with landscapes, but again, on these shots, that’s definitively a real surprise.


I know I cannot come to a conclusion with just one shot, I will do more tests of course, but so far I have to come the following conclusion: a modern compact camera is just great for taking daylight and still subjects, and DSLR are not always so useful then, at least DX DSLR. Last and not least, smartphones don’t seem to be able to challenge high end compact cameras so far.

If you have made similar tests, please let me know.