A New Lens - August, 2017

For the past couple of years I've been using a Sigma 50-500 lens on my camera for all my photography. It's a lens I'm more than pleased with as it is extremely versatile and gives good results. The versatility is not just because of its range of zoom but also in that, most unusually for a larger lens, it has a very useful macro capability - it's possible to focus down to 3 or 4 inches (75 to 100 mm) from the end of the lens hood if the focal length is wound back to around 150 mm! However, for a while now, I've had a hankering for a dedicated macro lens. The reasons for this are several:-

• The 50-500 will not allow the use of on-camera flash for macro work as the objective end of the lens is so large that the subject would be in shadow from the flash.

• The 50-500 is quite heavy, and a long session out in the field can be quite tiring.

• The 50-500, whilst good, does not give the level of detail that can be obtained with a dedicated 'prime' macro lens.

• When shooting in macro mode, I tend to spend quite a lot of time on my knees. When getting up, from a kneeling position I find that these days I need to use my hands to help me up. This left the lower end of 50-500 resting on the ground/mud or in the vegetation.

On Friday 18th August, I took delivery of a Sigma 150mm F2.8 APO Macro EX DG OS lens. Sadly, I was at Birdfair that day, all day, so didn't get to try it! I chose this lens because:-

• The relatively long focal length for a macro lens would give me the 'reach' to enable me to take photos of 'timid' subjects such as dragonflies and butterflies.

• I could use on-camera flash without obscuring the subject.

• It has the reputation of allowing really crisply detailed macro images.

• It is 820 gm lighter than the 50-500, which doesn't sound a lot different, but makes all the difference at the end of a long day!

• It is 21 cm shorter than the 50-500, so doesn't tend to end up resting in the mud.

On the negative side, the 150 macro obviously doesn't have the versatility of the 50-500.

I got my first opportunity to use the lens in my own garden the following day (19th August), when I found an Elephant Hawk Moth caterpillar on the lawn in the early morning. The lawn was in shadow, but the sun was shining brightly elsewhere in the garden, so I moved it onto a low garden wall. The first thing to strike me about using this lens was that I was now having to adjust my position in order to frame the subject as I wanted it, rather than wind the zoom lens in or out - an obvious situation, but something that I'd not thought about, and takes a bit of getting used to. I had mixed feelings about the results - I was expecting a relatively shallow depth of field, but not that shallow! For some reason I seemed to be getting more contrasty results too. In the images where the sun was shining I've had to apply a significant degree of 'shadow protection' to the images to bring out the detail in the shadows. For those not familiar with this species, the caterpillar has an extremely large body, coupled with a very small head.

The images I show below are of a relatively mixed quality and the poorer ones are included to illustrate a point. All were taken with the camera handheld.  

Elephant Hawk Moth (Deilephila elpenor) (caterpillar) - ISO 1,000 ; 1/200s ; f16 ; -0.7 EV

ISO 1,000 ; 1/400s ; f7.1 ; -0.7 EV

ISO 1,000 ; 1/200s ; f7.1 ; -0.7 EV

I then looked for another subject to practise on and found this 3rd instar nymph of  a Common Green Shieldbug. This was probably only about 8mm long. I was, therefore, pleasantly surprised to see that it was possible to see the elements in its tiny eyes. The second image below is a tighter crop on the first image.

Common Green Shieldbug (Palomena prasina) (3rd instar nymph) - ISO 250 ; 1/1,250s ; f7.1 ; -0.7 EV

I then tightened the aperture to f14 in order to get a greater depth of field. It helped considerably. 

ISO 1,000 ; 1/160s ; f14 ; 0 EV

On reflection, I prefer the first image, with the out-of-focus area adding to the effect.

I next found a slightly larger (about 10mm long) 4th instar nymph. The legs are quite badly out of focus in this image.

Common Green Shieldbug (Palomena prasina) (4th instar nymph) - ISO 1,000 ; 1/200s ; f14 ; 0 EV

Whilst the caterpillar had been on the ground, the shieldbugs had been on a fuchsia plant and were being blown about in the breeze somewhat. Many of my attempts had, as a result, turned out totally unusable.

The next day (20th August) I had another brief session when I tried to photograph a butterfly for the first time with the lens. The weather was dull and the subject was in fairly poor condition so I didn't try very hard! The results were, from my point of view, 'below average' - the body hairs don't show.

Peacock (Aglais io) -  ISO 1,000 ; 1/400s ; f11 ; -0.7 EV

I had better results, however, when I attempted to photograph a tiny 'flea beetle' on a fuchsia (I'd been looking for the shieldbugs again) with the same settings - although I was using auto-ISO and the light was better so the ISO came down. This beetle is only 5 mm long, and again I could see the elements in the eye in the image.

Altica species (possibly Altica lythri) -  ISO 500 ; 1/400s ; f11 ; -0.7 EV

My first session with the lens, out in the field, was on 23rd August when I went to Alvecote Wood for a Wednesday evening 'open evening'. Sadly there was little sun and a strong breeze, so I saw very little to try the lens on.  I did manage to get some usable images, but it was extremely difficult as everything was moving around in the breeze, and the results were well below par - I'd possibly have done better with the 50-500.

fly species (possibly Nemorilla floralis) -  ISO 800 ; 1/640s ; f13 ; -0.7 EV

Six-striped Rustic (Xestia sexstrigata) -  ISO 1,000 ; 1/250s ; f10 ; -0.3 EV

A bit disappointed at how little I'd seen, I headed homeward. However, I did appreciate the benefit of carrying the lighter lens for the evening.

I arrived home to find another subject for my camera. A Vapourer caterpillar was on the doorstep! It was dusk by now, so I popped up the on-camera flash. Although it does not look natural, I'm quite pleased with the result.

The Vapourer (Orgyia antiqua) (caterpillar) -  ISO 1,000 ; 1/250s ; f10 ; -0.3 EV ; on-camera flash

On Thursday 24th August my wife, Lindsay, alerted me to a 'beautiful moth on the mint'. It turned out to be a relatively common micro-moth - the Small Purple and Gold. This species is around 8 mm long, and was another useful subject to try the lens on. As it was partially in the shade, I used the flash again to fill in the shadows.

Small Purple and Gold (Pyrausta aurata) -  ISO 1,000 ; 1/400s ; f11 ; -0.7 EV ; on-camera flash

By now, I was feeling that I needed a more intense session somewhere in order to really assess the lens, and learn how to correct any mistakes I'd been making. I'd been getting very mixed results, and I needed to understand why. Fortunately, I did not have to wait too long before such an opportunity came along - but that will wait until a later post. 

I have already come to the conclusion that the optimum aperture for the 150 macro lies somewhere between f10 and f14. Larger apertures, with their smaller depth of field, have their place, particularly if I can get the subject flat-on. However, for some reason that I've yet to figure out, small apertures (f22 for example) seem to frequently give poor-quality images - dreadful lack of sharpness in spite of what should be adequate shutter speed. I have a suspicion that I might have a fault with the lens (possibly with the image stabilisation), or an incompatibility factor with the camera, particularly as I sometimes hear a buzzing noise from the setup as I'm shooting. This will be an ongoing investigation until resolved.

With regard to the 50-500 lens, that will, I believe, remain my lens of choice when going out on a birding or general nature watching session. However, when the prime target is uncompromisingly butterflies and/or dragonflies, the 150 macro is already proving its worth and will be favourite.

Thank you for dropping by. My next post will probably revert to catch-up mode and feature pre-macro images.