focussing speed and accuracy

Hello all,

I haven’t posted here since purchasing my first DSLR set up last year (10D, subal-C10, sea&sea strobes). Thanks for your help in making my purchase decision. It's been an awesome learning experience.

I mostly shoot fish and would like to get more into documenting fish behavior, esp. spawning. For fish portraits I use the 50mm sigma and 100mm cannon. I like the 100 for shyer species because of its tele-macro capability and the 50 for fish that let you get close. The 10d has nine focus points but most of the time I only shoot with the center one for accuracy, lightly “pumping†the shutter release while following the fish to maintain focus. Even though the percentage of in focus shots is ok I find that a lot of the time the interesting “poses†I want to capture are lost because the camera is either searching or the shot is out of focus, especially with the 100mm. There’s little I can do to improve this with lenses but I know there are faster cameras.

So my question is would a higher end model like the canon 1D markII make an upgrade worthwhile?

I played around with both cameras (10D and 1D markII) at the store in different light situations and was surprised not to find a huge difference in speed (though the difference in crop factor was quite apparent!). But perhaps someone who has experience with these cameras underwater can say otherwise. Changing cameras would require a change in housings as well so the investment would be substantial.

My main reason for upgrading would be to increase focusing speed and accuracy. Secondly, its nice to finally have housing that would not need to be upgraded every time camera technology improves (unless Canon decides the change the 1D line as well!). I am quite happy with the quality and features of the 10D otherwise. Any comments would be appreciated.

I shoot the same combo you do, however, for fish shots, I use the EF28-105 zoom behind the FP-94B. What' focussing mode do you use? I find that I get great success setting the camera to AI servo instead of one shot. I get a much higher percentage of keepers this way.

Stu

I think that you are right that you have the best lenses for the job. The problem with many zooms is that they will not focus as fast as prime lenses.

Part of the problem is that your camera has very good AF is bright conditions, but not so great in low contrast and low light, e.g. dusk - when interesting behaviour is going on. You could try a spotting light. I know my friend Giles uses that with his Canon at dusk, when I don't need one on my camera.

The 1D is a big step up in performance, but also a big step up in price. It would be an excellent choice for that type of photography. Just not a cheap one. If you can afford it you will not be disappointed.

Although I have no evidence I think Canon will change the body for the next generation of the 1D serious. General opinion is that Canon is equal to or ahead of Nikon in every area apart from body ergonomics in their pro bodies. It would make sense for them to change the body.

Alex

I use a 1DS with both 50 and 100 macro lenses. Whilst the focus speed is very good and accuracy excellent, you are probably suffering from subject failure - that is a subject which often has inherently low contrast and is being photographed in low contrast conditions (underwater).

What may well make a difference might be a good spotting light - I am spoilt because I am able to access my strobe's built in focus light from my housing so I can illuminate a subject until focus is achieved then release the switch and fire the shutter almost simultaneously. Even this is not foolproof but does increase the hit rate substantially - unfortunately this system is not available on all housings and flash units. Simply changing from your existing camera to a 1D series may not in itself solve your problems - there are many reasons for using a 1D series camera but the enhancements in focus speed/accuracy are not massive and I doubt that in themselves they would make the change viable.

Speaking as an ex-Nikon user, I did find the ergonomics of the Nikon to be easier to get on with, but the more I use the Canon, the less of an issue this remains. Ergonomics underwater are very different and may also be a big factor too.

I don't think the problem is your lenses. Having used both a 1D MkII and a 1Ds MkII, I can attest to the fact that both are very quick at focusing, particularly with the two lenses you're using (I use the same two). As Alex said, one of the key issues--esp. with the Canon 100mm--is light; if you have enough light, it focuses FAR faster than it will in dim conditions. Shooting in early morning or at dusk, you definitely need a good modeling light.

Having said all that, to make a significant step up (in terms of technology, since the newer Canon models do seem to have better/quicker AF than older models), I'd seriously consider the 5D. It is cheaper and significantly smaller/lighter than the 1D series, gives you full frame sensor like the 1Ds, and should have AF capabilities similar to the 1D MkII, but with half again the resolution. It will also likely be more considerably cheaper to house.

I, too, started with the 10D in a Subal and shot with both the Sigma 50mm and the Canon 100mm macro. I have learned a great deal with that setup and have been able to get some shots that I am pleased with.

Although I have a long way to go to get better and I am in no way equal to the the majority of the capabilties of the 10D, I found myself wanting to upgrade. One of the biggest reasons was the accuracy of the AF.

My camera didn't hunt as you said yours does. Mine would lock and fire the shot fairly quickly. But too high a percentate of my faster action shots both above and below water (such as faster moving fish or things like harbor seals) would be out of focus or just a bit soft. I'm talking about shots taken with center point focus and every other combo I've read about on different boards.

Further even some of the shots that I would have said were in focus aren't super sharp (and can't be sharpened to the point where they look super sharp). This was true of even stationary objects.

I sent my camera in to Canon along with some lenses. They calibrated them and it did get a little bit better. But it wasn't the kind of improvement I'd hoped for.

To be fair I've had little other AF camera experience to compare it to. I have since played around with a 1DMKII. But I didn't get a chance to play around with it in a situation with faster action or look at the sharpness in the fine detail. I'm not really surprised that you didn't notice a big difference when you played around with the MKII at the store; I didn't notice a big difference in my 5D until I'd had it for a couple of days and got a chance to shoot some situations I'm familar with.

Alex talks about low-light AF difficulties. The AF problems I had with my camera weren't low-light exclusive.

When the 20D came out I wondered if that would be better. But I never really considered it in more than passing as it wasn't, in my mind, enough of an upgrade.

However, when the 5D came out I got one. I'd always wanted a FF camera and it has less noise, more pixels, instant start up, a bigger viewfinder, better metering, and I had hoped when I got it that the AF would be better.

So far I'm quite pleased with the camera. I wish I could say the AF is perfect, but, in my opinion, it is not. But it's very very good.

I'm still waiting on my Subal but above water it handles fast action pretty well in the shooting that I've done so far. The biggest surprise in the upgrade though has turned about to be just how much sharper things in focus actually are. I have been really blown away by this. That extra bit of sharpness even in just one small detail of an image can dramatically change the overall look of the entire image.

The other day was looking at some shots of turtles I took in Hawaii recently with the 10D. I was going through them to pull the selects and I found myself opening images with compositions I liked that would end up, on closer inspection, a bit too soft to make the cut. (I can only imagine how much sharper some of those images would be I'd taken them with the 5D.)

Looking back I personally would never have considered spending all that money to upgrade for slightly better AF speed and accuracy. But knowing what I know it certainly would have been a bigger impetus for considering an upgrade, as you're doing now. When you find yourself passing over images for no other reason than that it's not in focus, that's clearly a problem.

As I said, I've bit the bullet and gone the FF route. It's a very big and costly move for me. But I'm very happy I did it. I'm biased to FF and would suggest you check out the 5D in addition to the MKII.

From the sound your post I suspect I was feeling like you're feeling. I hope this helps. Good luck.

P.S. Paul posted about the same time as my last one did, but as you can see, the common theme in these replies is LIGHT.

FWIW, after searching and searching (and trying several alternatives), I just recently ordered a Fisheye HG20DX Focus Light (available at www.backscatter.com). I've read VERY good things about it, and one of the big attractions for me is the fact that it has a variable output, so you can adjust the light level to your situation/conditions on any given dive. It's pricy, but for your situation and specific needs, it might make more sense to spend $500 on a modeling light than to spend many times that much on a whole new camera & housing...at least you could try going that route and see if it solves your problem...

I'd be very interested to hear if anyone has tried a non-usm Canon 100mm macro lens on a current camera. I sometimes wonder if the high focus speed of the usm lens means that it overshoots too easily in low light, low contrast conditions!

Anyone?

Stu, I've experimented with both AI servo and one shot mode. You're right, AI does give me a higher percentage of in focus shots but only if I have enough available light. I should have pointed that this problem occurs in lower light conditions, near dusk. As Alex pointed out this is the most exciting time to document fish behavior. One shot allows for focus lock so when the subject is located in or moves into lower light conditions I seem get better results by slightly pumping the trigger, locking the focus when there is enough light and waiting until the subject comes into focus. I should actually experiment with AI focus, that may give me the best of those worlds (I just started diving at dusk a week ago to document fish spawning).

Of course, also, some kind of modelling/focus light may be the answer to my problems...and a much cheaper one.

Frank

Hi Frank,

I use the UK SL4 (30 bucks)as my main spotting light, it's always on the housing. I turn it on when needed. I've used this with AI Servo to great effect on pretty much any subject from Pygmy Seahorses to Mature Emperor Angels. However, when I shoot mandarins, I felt that I needed a broader beam, so I used a UK D4R (80 bucks) as my spotting light. It gives a softer diffused light than the SL4 and the 8 watt bulb isn't blinding. I've read some reports that the AI Focus mode usually gives you a softer 1st shot then the AF catches up. I pretty much always use AI Servo underwater, and with the 28-105 being a USM lens, hunting isn't as painful as my 50 or 90 (Tamron) macros. I've printed pin sharp images taken with this lens upwards of 20x30 on a Kodak LED Printer.

I'd like to get the 5D next but other life things get in the way.

Paul, 2 of my dive buddies uses the non-USM 100 on their 10D, they have no problems with focus accuracy.

my 2 cents.

Stu

... I should have pointed that this problem occurs in lower light conditions, near dusk. As Alex pointed out this is the most exciting time to document fish behavior. . . I should actually experiment with AI focus, that may give me the best of those worlds (I just started diving at dusk a week ago to document fish spawning).

Of course, also, some kind of modelling/focus light may be the answer to my problems...and a much cheaper one. 

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Frank,

One other thought. If your camera allows you to modify custom functions to use the * button to AF instead of the shutter (I'm not sure if the 10D allows that, but I think so), you might consider using * AF in conjunction with a manual focus ring, rather than depending on AF alone.

You can use the * button to get "approximately" focused, and then use the manual focus knob to fine-tune focus on your subjects as they/you move around a little. I just started doing this on my latest trip, and it worked SO much better (once I got the hang of it) that it will be my standard MO from now on.

This method can make a BIG difference. For example, on that recent trip, I spent the last 10 minutes of a late afternoon dive (no modeing light, so low light) with a blue-ring octopus "on the move", and my 150mm lens (similar to your 100mm with your crop factor) just hunted and hunted in the dim light every time I tried to AF. I'd have been lucky to get one or two shots using AF, but I used the above method to manually refocus as I "tracked" him along the reef, and got about 20 shots of him instead...if you're shooting fish life at dusk, even with a modeling light, you might seriously want to try that approach.

Really interesting tips and discussion here. I hope some Nikon users have a read too.

Alex

Lots of techniques to try here.

I think I need to experiment a little more with the 10D and perhaps add some light. Upgrading seemed like the easy way to get better shots but it really doesn't do much for my skill level. Besides, subals 5D housing probably won't be available for a few months...

Thanks for your tips everyone.

This discussion really helped.

Very intresting discussion.

I to have, with my Nikon, sometimes the same problems - low contrast - low light.

I have never thing about a focus light becauce I never use strobes.

But maybe thats the solution. The Question is if there is a focus light that can be activated with the shutter release button on my Nexus housing. Becauce If i have it always on there will be a color chainge on the Photos, or??

lambis

...I have never thing about a focus light becauce I never use strobes. . .

The Question is if there is a focus light that can be activated with the shutter release button on my Nexus housing...

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I just recently returned from a trip with Mike O., and he has a focus light activated by half-pressing his shutter release (it worked GREAT for photographing mandarinfish at the last minute when mating!). As I recall, he rigged it up himself, and although he has a Canon camera, perhaps he can explain how he did it, and that might be of value to others (with various cameras/housings).

BTW, Mike O. is also the one who "taught" me the method I posted earlier in this thread -- using the * button for AF to get roughly focused on something, and then using manual focus to fine-tune it. I should have given him credit in my earlier post (didn't mean to make it sound like I came up with the idea myself! ).

Focus light activated by half-pressing the shutter release:::cool

Maybe its working togehter with the heinrich adapter but i am almost sure that they must existing focus lights with this funktion

cant wait to read more...

lambis

Focus light activated by half-pressing the shutter release:::cool

 

Maybe its working togehter with the heinrich adapter but i am almost sure that they must existing focus lights with this funktion

 

cant wait to read more...

 

lambis

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Alas, I am not as clever as Bruce has led you to believe. Though I do have a Matthias converter, and have configured it to work on the half-press with INON strobes should I actually install the converter permanently and buy INON strobes , my shutter-activated light is a stock Sea&Sea accessory that works with a limited set of their housings. It is connected to the camera's PC port through a bulkhead connection. My assumption is that it is reading whatever signal the camera would give out to communicate with a studio strobe's modeling or metering lamp . . .

Here's the site: http://www.seaandsea.jp/products/accessory/acce/light.html

Mike

PS My next step is to try to add some red gel to it (or order another and make it the "red lamp") for shy critters on night dives and pygmy seahorses . . .

I haven't had a lot of experience with focus lights, but thinking about the kinds of shots you would be wanting use it for Lambis (freedivers), I wonder how much use it would actually be? I guess it depends on how far away you are from them.

I would think that you might ahve more success by practicing your focusing technique so you get that central D70 sensor on part of your subject (the mask?) that has reasonable constrast on its edges.

Perhaps someone else with further experience will add to this, but in my experience I can't see a light being a huge amount of help for wide angle freediver shots.

Anthony you may are right. I stull have not very mutch experience with DSLR. After one photo trip I am still new and novice.

I MUST make a trip just to test thinks out and PLAY wwith my camera.

But its nice to know that there is a focus light that works with shutter release.

BTW I have a UK40 light on my mask but it is worhless for as focuslight

When i use the 16mm lens I am about 3 meters from the freediver (For fullsize portait) with the 10,5mm I am very near and there I have not a problem to focus becauce tis easer for the camera to find a detail. Less water between object and port helps a lot.

Thats, I think, is the reason that it was more hard to focus with my 16mm in Egypt.

Lambis