Need help with macro shots!

[pwfletcher]

Using a Nikon D100, Sea & Sea DX100 UW housing, Nikkor Micro 105mm lens. The problem that I am having is that the automatic focus lens keeps cycling all the way from end to end when trying to lock on a subject. By the time it comes back to lock, the subject has moved and the lens goes through the cycle again. Has anyone else had this type of problem focusing with an AF lens? If so, how do you solve the problem? I just got the lens yesterday and hope that I didn't spend $700 for something that I can't use.

 

[Crispy]

pwfletcher,

The camera is probably having problems focusing for one of these common reasons: The camera is not able to "see" enough contrast between subject and background. this can often be corrected for by shiffting to the edge of your subject and obtaining a focus lock and then refraiming while maintaining your focus lock and taking the picture. Another possible problem is that the housing (and macro use) is prohibiting the I/R focus assist light from helping the camera focus. (this is the red light emitted from the camer in low light situations) your camera will use this light to help it obtain focus. I'm not familiar with the Nikon D100, does it have manual control over it's focus modes? Look for Servo or Single (becareful not to confuse for the film drive). Try to set to single which means that the camera will focus lock as opposed to servo focus (track a moving object).
Also If you are using a "picture mode" as opposed to manual you may want to see if there is a macro mode which some times helps with the focus issue by setting the focus drive accordingly.

I hope this helps

-Crispy

 

[BradfordD]

pwflecther,

The Micro-Nikkor 105 is a wonderful lens! However is does have the tendency to "hunt" (AF cycle) in anything less than ideal conditions. Situations in-which the lens tends to AF cycle would be low contrast shots (dark subject w/dark background - and to a lessor degree, light subject w/light background), backscatter (cloudy water, sand/silt stirred up, and small invertebrates swimming in the foreground), and movement (either yourself in the surge - or your subject).

For the most part however, a strong focus (modeling) light will minimize this AF cycling... I have used several different focus lights (strobe and/or hot shoe mounted) and have found the best to be two UK40 focus lights mounted in tandem on the hot shoe...

As the D100 has the same CAM focus as my N80 (mine is housed within the Sea&Sea NX-80), I would suggest that when shooting macro you set your camera to Single Servo AF (as opposed to Continuous AF) and Single Area AF Mode (as opposed to Dynamic AF Mode) - assuming your subject is rather static and not moving erratically. If you do decide to shoot macro in Dynamic AF Mode, I would suggest you shoot WITHOUT Closest Subject Priority (CSM 9-1)...

Also if no one has told you, the Micro-Nikkor 105mm tends to AF cycle more than the Micro-Nikkor 60mm. This does not appear to be a problem above water as much as underwater. Underwater, the further subject-to-camera distance of the 105mm over the 60mm DOES make a difference. Since you have the lens and the ports, you might consider getting the AF/MF focus gears - for those times that AF just won't work.

I hope this helps, as well... You are the first real time person I have heard that has the new Sea&Sea DX100 set-up, and I would be very interested in hearing about your thoughts and findings of the D100 and DX100...

--Brad

 

[pwfletcher]

Part of the problem could be that this morning was the first time that I have used the camera and conditions were less than optimal (big waves, low vis, beaucoup surge).

I just went over and talked to Joe Liburdi, who originally suggested that I get the 105mm lens, and he offered basically the same advice ... wait for better conditions so that the lens can find better contrast to focus on and use a strong focus light. In addition, less surge will obviously make for a more static shooting situation.

As far as handling goes, the housing is neutrally buoyant, easy to maneuver, and the camera controls are flawlessly designed (easy to use even with my gloves on). In conclusion, I must say the Sea & Sea housing is absolutely spectacular. Now, I just need to learn how to use the camera!

 

[BradfordD]

Great to hear about about your positive initial feelings for the D100 and DX100.... I'm thinking this would be my natural progression into digital SLR and U/W housing (so that I can still use my Sea&Sea ports and gear).

I'm sure Joe Liburdi will provide ALL KINDS of helpful information (Joe being the author of "The New Guide To Sea & Sea")...

But, with the 1.5x crop factor of the D100, your new 105mm lens would work out to be about a 160mm macro lens... pretty powerful - and hence tougher to macro focus.... Might a 60mm worked out better for you???

I've been in that "surgey stuff" you call Southern California diving, and can only say that it's better than the "surgey soup" I dive in Northern California!!... Seriously, you should have some excellent opportunities to dive between storms - this time of year is the clearest waters for my Monterey diving.

I've heard that the housing is much larger than the other Sea&Sea housings... do you notice this while diving? I've also been told that the DX100 is almost perfectly neutral underwater - which would be a great thing, as my NX-80 is negative about 2-3 lbs... Also, will my YS-120's work with the D100?? I notice that your set-up includes what looks like a YS-90 but which one? Sea&Sea now makes THREE different models of the YS-90... :bonk:

--Brad

 

[pwfletcher]

I completely forgot about the 1.5x factor! Yes, the 60mm would work much better! Off I go to the lens store to make the exchange ... stay tuned

 

[BradfordD]

Gosh, I hope I didn't talk you into changing your selection of macro lens... The 105mm is a GREAT lens! I think that adding a STRONG focus light would be the first option for trying to minimize AF cycling issues. You may have the same or similar AF problems with the Nikkor 60mm.

Dealing with the 1.5X crop factor are all part and parcel of owning this batch of DSLR's... Be aware, along with the 1.5X crop factor with the standard lenses you will be using, the Depth Of Field calculations will be different as well.

Because the CCD on the D100 is smaller than a 35mm film plane, the D100 will have a smaller (contracted) DOF compared to the 35mm film tables. This is not so noticeable with landscape shots where the DOF is less important - but it does become more critical with portrait and most importantly with macro.

--Brad

 

[blacknet]

Hello,

One of the golden rules of underwater photography is never ever EVER use autofocus. Manual focus is your friend.

Ed

 

[scorpiofish]

The 105mm tends to hunt. Part of the problem is that there the lens actually changes focal lengths.

The 60mm does work better, but I'm a big fan of the 105mm for serious macro work.

But, with the 1.5x crop factor of the D100, your new 105mm lens would work out to be about a 160mm macro lens... pretty powerful - and hence tougher to macro focus.... Might a 60mm worked out better for you???

The lens dynamics shouldn't be effected since it is just a crop. The reason it's harder to focus is that it is harder to isolate the focus point.

I've got the 60mm, 105mm and 200mm macro lenses. Focusing the 200mm is difficult just because of its length and trying to keep the focus point the focus point.

Constant surge destroys the AF possibilities of the 105 and 200.

I've also used the 105mm with 2x tele. Again, very difficult to AF because you have now lost 2 stops of light.

I intend to use the 105mm with the D100 as soon as Aquatica starts shipping their AD100 housing. I prefer the streamlined housing versus the box design of Sea & Sea or Ikelight.

Another tip for using the 105mm, if you haven't already traded it, is to limit the amount of refocusing you do. If you constantly try to readjust the AF, as in surgey conditions, the moment the AF sensor picks out something far away from the subject plane, e.g. background coral, it will start hunting, extending itself all the way out.

 

[BradfordD]

scorpiofish once bubbled...
The lens dynamics shouldn't be effected since it is just a crop. The reason it's harder to focus is that it is harder to isolate the focus point.

Scorpiofish,

While I don't completely agree with you (the lens dynamics ARE effected by the crop... i.e. contracted DOF), I do agree that shooting with what would be effectively a 160mm macro lens would be harder to isolate and focus on your subjects... Additionally at 160mm one might be forced to back up too far (depending on the subject) which would put a larger column of water between you and the subject which could effect the overall quality of the image....

I think the Micro-Nikkor 60mm (effectively a 90mm macro lens on the D100) would be a much more versatile lens, for 1:1 macro and some small fish portraits...

As to my thoughts on Auto Focus vs. Manual Focus.... I'm a BIG fan of AF... I'd say that 85-90% of my shooting is with an active AF lens. The newer Nikon SLR cameras (F5, F100, N80) have fantastic AF chips and sensors. These same AF chips and sensors are also used with the D1/D100 DSLR's. Of course there are times when AF just won't work, but I have found that these situations are rather rare. In most instances, AF works at least as sharp as MF, but focuses on the subject FASTER as well. All this allows me to concentrate more on my composition and aperture settings...

Just my $0.02

--Brad