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Bob_W

Member Since 20 Jun 2007
Offline Last Active Sep 27 2016 08:12 AM
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Posts I've Made

In Topic: Back Button focus/Nikon D7100

15 September 2016 - 03:54 AM

Thanks for all the helpful info.  Yes, I use AF-C and spot focus.  So I pick a point to focus on (using the back button), focus lock and then let go.  Then when I go to shoot, it's out of focus again...so I start all over and the continuous focus is going crazy trying to focus.

Everyone keeps saying how great BBF is, but so far, it's just as difficult as using shutter release focus.  I will keep practicing.

Thanks to all for taking to the time to answer.

 

Don't let go! The 'C' will only follow while the focus is activated. It's not an on/off switch. If using AF-S, holding the BBF lever will lock the focus, and then you will have to rock to maintain focus on the focal point.

 

Bob W


In Topic: Back Button focus/Nikon D7100

06 September 2016 - 03:50 PM

I am having trouble mastering BBF, especially on macro/supermacro. (I have a 60mm on my Nikon D7100)  Seems to me, BBF is really like manual focus...because if you move one little smidge, your image is out of focus...like when shooting a pygmy, etc. The whole "recompose" issue seems irrelevant, because you are constantly trying to focus...I feel like I'm missing something...can someone explain?  I'm sure it's "operator error"  :lightbulb:

 

A lot of people using auto focus will use spot focus. Assume a nudibranch sitting crosswise, left to right. They 'compose' the shot by moving the focal point to where they want the focus to be. Example, rhinophore 1/2 inch up, 1 inch to the right. They then focus on the rhinophore and shoot. Using BBF, the 'one little smidge' is the key to the whole thing. You leave the focus spot in the center. You focus on and lock on the rhinophore. Holding the lock, you recompose you image so that the rhinophore is 1/2 inch up, 1 inch to the right. You rock the camera in and out (one little smidge) until the rhinopore is again in focus, then press the shutter. It's an acquired skill, but once you master it, you'll love it. All the time you save not having to keep moving the focal point around. And it's easy to relock.

 

Bob W


In Topic: E-M10: Why no 2nd-C flash for P or A modes?

12 August 2016 - 04:48 PM

I posted a more detailed version of this in the Mirrorless subforum, but have gotten no answers.

 

http://wetpixel.com/...showtopic=58412

 

Can anyone tell me what my Olympus OM-D E-M10 has a 2nd-C flash setting for S and M modes, but it doesn't offer the same for P or A modes?

 

In P or A, the only 2nd curtain sync option it offers is SLOW2 which gives VERY slow shutter speeds. In S or M, it has Fill-in Flash, which syncs to the 1st curtain, and 2nd-C which appears to work just the same but sync to the 2nd curtain.

 

In P and A it has Auto and Fill-in, which both sync to the 1st curtain, but no flash mode that works the same as Fill-in except to sync with the 2nd curtain.

 

Why is that?

 

I want to use A mode with Fill-in flash synced to the 2nd curtain and my camera doesn't seem to have a way to do that. My thought is to use A mode to control depth of field and 2nd curtain sync so that if a fish is swimming fast, it will have a trail behind instead of in front.

 

I'd also like to know why, when I use A mode and SLOW2, my camera is firing the flash twice. The manual seems to indicate it should only fire once, just before the 2nd curtain. It's easy to tell that it flashes twice when the shutter is open for 15 to 30 seconds.

 

Thanks in advance for any help.

 

ps. Yes, I know someone is going to say "just use M mode". Thanks, but that doesn't answer my questions. :-) If I'm trying to take pictures of sharks, there's a good chance I won't have the time to sort out good M settings (I think), so I want to take advantage of the "help" the camera will give me in A mode. Furthermore, I just want to understand the theory and why the camera doesn't have 2nd-C in A mode.

As I read your question, and then review the E-M10 manual, what you are really asking is "Why is the E-M10 designed to operate the way it does". And it is NOT designed to do what you are trying to accomplish. To do what you want to can only be done in S/M modes. In both of these modes, you set the shutter speed and the camera then knows what to do with the flash in relation to the curtain. In P/A modes, the camera is using the shutter speed adjustment, in combination with the aperture, to achieve a good image and is unable to tack a flash on the end of the activity (2nd curtain). There's just too many variables to manage. So the answer really is "just use M mode" or S. With experience, and it doesn't really take all that long, you will be able to 'guess' at an initial setting. Take a shot. Review the image. Make adjustments. The shark will more than likely still be there for another shot.

 

Bob W


In Topic: My New Book: Underwater Photography Masterclass

30 July 2016 - 06:07 AM

I just received a 'ship notice' from Amazon US for the book I pre-ordered on March 5th. It is supposed to arrive on August 1st. Because of the delay, I had ordered the book on April 8th from Amazon UK and received it on April 20th. Hopefully, Amazon has gotten their act together and it will go smoothly for everyone from here on out and books will arrive in a reasonable amount of time. Enjoy!

 

Bob W


In Topic: Help with strobe settings

21 July 2016 - 07:21 AM

 

How does that work? Doesn't that mean that the camera is controlling the flash intensity and duration, even though you're in Manual mode? I infer that there is a separate camera setting that controls whether the camera flash is in Manual mode or automatic? So, if the camera is in M but the flash is still in A, then despite your manual settings for A, S, and ISO, the camera will still light the flash if it thinks it needs to?

 

I had assumed that putting the camera in M would mean that the flash was also in M mode and you would have to manually set it if you wanted it to go off when you snap a picture.

 

Note: I'm talking about the camera's built-in flash because I think with a fiber optic cable, the camera's built-in flash controls the external strobe as well, right? Assuming the external strobe is in TTL mode, that is. So, whatever the answer is here, it's the same answer whether you are using an external strobe (in TTL) or not, right?

 

That depends!. There are 3 different things involved in the process, each controlled separately:

1) the camera - f/stop, shutter speed, ISO in manual mode. Variations of control in the other modes..

2) the built in flash - depending on your camera, it may be able to be set to only fire when needed, fire full all the time, only fire fractional power, etc.

3) the external strobe - it can be set to TTL where the on/off mimics what the camera flash is doing as seen through the fiber optic cable. The strobe has no idea what's going on, it's just doing what it's told. You can use the the rotary dial to tweak the light from the strobe. Or it can be set to manual mode, where the light from the camera through the fiber optic cable is just a trigger for the strobe. It then fires based on the settings on the rotary dial. If your camera uses a pre-flash to make it's adjustments, you have to use the 2 lightning bolt setting on the strobe so it knows to ignore the 1st flash. Otherwise the strobe will fire on the pre-flash and won't be able to recycle quickly enough to fire when the shutter opens. conversely, if your camera doesn't use a pre-flash, and you tell the strobe it does, the strobe will ignore the flash and wait for the 2nd, which never comes. Ideally, when using the strobe in manual mode, you should set the camera flash (if capable) to fire all the time at it's minimal power setting. That way, you get enough light through the fiber optic cable to fire the strobe, but conserve battery power that would otherwise be wasted firing the camera flash at a high power.

 

Bob W