First dives with sigma 150mm macro.

James posted a picture a while back with this lens. Well I just got done with 10 dives with the Sigma 150mm macro - I though I would share my experience.

I used the sigma 150mm f/2.8 macro lens with a 500D close up filter. As I posted before, this lens is a VERY tight fit in an Ikelite port. The lens diameter is to much so the focus range button rubs the edge of the port and the lens is therefore forced to be slightly off center in order to fit in the port.

But it does fit well enough that the housing is water tight. Though I wouldn't recommend taking this combo underwater without insurance..

The close fit doesn't as far as I can tell effect the picture quality.

On two dives I was not careful when putting the port on and the port rubbing on the focus range switch was moved to a limited focus range. The port is clear and it is easy to see if the button has been moved but I guess I am not too observant because twice I went down with limited range of AF.

AF = very very tricky.

It works when it wants to. AF is really light hungry. If there isn't enough light it will not lock focus and therefore it will not let you take a picture. Even if it is exactly in focus if there is not enough light it will not allow you to take a picture.

Natural light is hardly ever sufficient for AF to lock. With both of the modeling lights from my two DS-125's illuminating the subject AF works very well and is quite quick up to about 1:1 It is surprisingly how fast and accurate the AF is once you get enough light on the subject.

Beyond 1:1 (1.4:1 is possible since I am using the 500D) AF has difficulties even when both modeling lights on the subject. I will probably end up with some kind of dedicated modeling light.

Over all this lens was ridiculously difficult to use compared to the canon 100mm. Since it always needs extra light to focus I am constantly having to re-aim the strobe/modeling light for each subject.

I really like the focal length and the close up filter combination. The extra length compared to the 100 made gobies and other small creatures much easier though some do not appreciate the modeling lights on them. The extra distance is especially nice as you approach 1:1 and beyond. With the 100mm I found that often I couldn't get close enough to shoot 1:1 or beyond because the strobes would hit the subject.

I also like that I am limited to a maximum subject size of 85mm due to the 500D. I was always tempted with the 100 to try to shoot larger fish portraits and they never came out because there was too much water between me and them. With the close up filter combination on the camera wouldn't focus that far even if I wanted to so there is no temptation.

At the closest focus the magnification ratio is 1.4:1 - the same as using a 1.4x teleconverter on the 100mm but without the loss in light.

Overall I like the lens and and feal this is an upgrade from the canon 100 though there is definately a learning curve. Most of the pictures posted are from the last day.

Some pictures. (levels and USM adjustments)

Bubble coral shrimp at the close focus limit. 1.4:1 This guy took me forever to get AF to lock at this range.

100% crop

Different species of bubble coral shrimp at about 1:1. AF was really hating these clear subjects, it took me 30 minutes to get this one.

Backing off more and AF was very quick. This goby is from a night dive. At night where the subject allways has to be lit by the modeling light no matter what lens I found the 150 no more difficult to use than the 100 was.

100%crop

At the maximum focus distance with the 500D on.

100% crop

Impressive results William....thanks for sharing

Karl

Thank's for the post William, I am adding that lens to my roster soon, I heard the focus was a dog in low light (glad the autofocus is so easy to overide to manual on this lens), I also like your comment on the limited range focusing with the 500D, get's rid of the bloody temptation to shoot far. But mostly I happy you could get every thing under ''sans problème''.

Regards

Thank's for the post William, I am adding that lens to my roster soon, I heard the focus was a dog in low light (glad the autofocus is so easy to overide to manual on this lens), I also like your comment on the limited range focusing with the 500D, get's rid of the bloody temptation to shoot far. But mostly I happy you could get every thing under ''sans problème''.

 

Regards

<{POST_SNAPBACK}>

Well MF is not an option for me - no chance that that lens would ever share its limited space in that port with a gear/clamp....

William,

Thanks for sharing! I really like your shots - awesome! This lens sounds like a good candidate for manual focus when shooting super-macro. Either that or a heck of a modelling light like a FIX light, etc.

Cheers

James

If your eyesight and viewfinder are good enough to confirm focus, you should shoot shutter priority instead of focus priority. In general I like the camera to take the pic when I press the shutter - regardless of what it "thinks"

On the Digital Rebel AF comes in two modes, ON and OFF. Nothing inbetween.

1) When you override AF using a HSM lens, does it still not force the camera to fire when you hit the shutter? I realize you can't fit a focus ring into the housing but just curious...

2) Would the russian rebel hack fix this problem?

1) In theory if the camera achieves focus lock you can then recompose/refocus and the camera will let you take so long as you hold the shutter button half way down the entire time. BUT only if the camera had locked focus before.

I said in theory because if the camera realizes what you are doing it will work. However if the camera thinks that the subject moved (as opposed to the camera moving) AF will track the subject.

In practice especially underwater refocusing/recomposing rarely gives good results. On land but it takes practice to get good at tricking the camera into working properly.

2) Short answer no it does not fix help.

It does fix the problem with the camera refocusing when you try to recompose, but it doesnt help the issue of taking a picture without focus lock.

The russian hack hacker quit a long time ago, he was replaced with another group who added features to the russion version. This group as quit now too. So it is unlikely that any new features will be added any time soon.