Ghosting and shutter drag

I just had the opportunity to shoot as a second for my first wedding on

Friday. Fortunately the main photographer was very relaxed and told me to have

fun, all of my shots are mine, and gave me a perfect chance to learn by

experience. Unfortunately, while she has a great eye, she has no technical

knowledge and could not help me with the problems I was experiencing with my

camera.

 

In the dressing room, as well as the reception hall, the lighting was dim to

very dim, respectively. And in these circumstances, I had a serious problem

with shutter drag and as a result, very few of my photos in these rooms turned

out as I would have liked. In the dressing room, there was movement and lack

of focus. I think that my problem was a low ISO, which I had set at 200. In

the reception hall (which was mostly candle lit), most of my shots had serious

ghosting. In this scenario, I was using an 85mm set in AV mode at 1.8, 1600

ISO and a 430EX flash.

 

Can anyone help me figure out what I was doing wrong? This is the first time I

have had the chance to use an external flash, and I would like to rectify my

problem ASAP compositionally, my shots looked good and I am so disappointed

that these problems happened at a time where I could not get help to understand

them.

 

I appreciate any help I can get!

If you are going to use flash as the main light, set the camera in manual and select a shutter speed of at least 1/15, but 1/30 would probably be better. This is usually enough to get some background illumination unless it is very dark.

 

Then set the aperture to whatever you think appropriate. f/2.8 to f/5.6 usually work well, but if you're going for that small DOF look, shoot it wide open.

 

Most of my wedding work is shot at 400 to 800 ISO. 1600 is reserved for very dark areas where I can not use flash, but if you have a 5D it's more acceptable.

Your use of the term "shutter drag" in your question implies you know what that is, yet, you used AV, which goes counter to using shutter drag in situations where you aren't on a tripod. You may want to read the following:

 

http://www.planetneil.com/faq/dragging-the-shutter.html

 

The basic theory goes like this. Flash will freeze subject motion and handholding motion by virtue of it's short duration--it kind of acts as a very fast shutter speed. Meanwhile, you can use slower shutter speeds to "let in" some of the ambient light so you don't have the dark backgrounds. However, you must underexpose the background in relation to your camera settings, by about two stops or more or you will get the ghosting and motion blur that you experienced. This is why AV is no good (always use manual camera mode for best control)--it tries to expose for the ambient light, not underexpose. When you are not using your flash and underexposing the background as above, you are subject to the handholding guidelines and motion stopping guidelines as per normal. Normally, you can't get frozen subjects using 1/30th and 1/15th shutter speeds (especially with longer lenses), but you can if dragging the shutter with flash while underexposing the background because the flash duration freezes motion.

 

You must have a good measure of flash on your subject to really freeze motion, so if your flash underexposes and you are less than about 2 stops underexposed on your background, you will begin to get motion blur. Also if your subject is moving fast. Anything correctly exposed by flash will be frozen--less correctly exposed, less frozen (as in foreground subjects lit by flash frozen, background subjects less lit by flash blurry). Also, if there is a bright area right behind your subject, you will get ghosting even if you are underexposing the general background, because the bright area throws your shutter drag proportion off.

 

Also, it isn't necessary to use such a high ISO and wide aperture to use shutter drag. Sometimes you may want the shallow DOF, but other times you may want a little more DOF or margin of focusing error, particlarly if there are multiple sutjects and any depth to your image.

And, I might add, shooting with a high ISO means you are putting yourself much closer to the actual ambient exposure and this makes it harder to underexpose your background by the necessary amount.

Heather - show us a picture that you have a problem with which will help all the boffins here figure out exactly whats up! Can you do that?

Thanks for trying to help! Here is an example of the problem I was having. Nadine, what I meant by shutter drag was that it seemed like it took forever for the camera make the exposure after I pressed the shutter button.

I think your problem is that the exposure is only 1/4 sec. The clearly defined areas are from the flash exposure, everything else is from... well, everything else.

That looks like classic "dragging the shutter" and Nadine is exactly right in her description. The flash exposes well, and the ghosts are the result of a slow shutter trying to expose the scene with ambient light. You get two images. One is stopped by the flash, the other is blurred by the motion of the subjects during the long exposure.

 

It looks to me like the camera was in Av mode, and automatically tried to give you a shutter speed appropriate for the ambient light with the selected f-stop. That speed was too slow. The "forever" the camera took to make the exposure was the result of the very slow shutter speed.

 

Try using Jim's method.

Jim's method.. or alternatively, if you're in a situation with similar but slightly changing lighting throughout the venue, you could use AV mode, but dial in some negative EC to yield shutter speeds that get you to 1/15 to 1/30th.. In your 1/4 second shot example, an EC of -2 stops would have brought you there. The advantage to -EC method of shooting is that you'll have consistent results of background vs. main subject differences in illumination.

I have found that in some low light conditions the "shutter drag" could be due to auto focus difficulties or if using the camera flash it could be the recharge time.

I don't usually use a slow shutter for dance shots like this. I might do a few to get an artsy effect, but mostly not. I would still keep the camera on manual, but select a shutter of 1/125 or so, and let the background go dark.

 

That said, I kind of like this shot.

I hope you get the concept from reading the article at the link I posted. It is important to underestand because you will have to change your shutter drag to camera settings proportion based on the ambient light present. Jim's suggestion will work in "most" darker reception venues, but you will run into trouble at say, a reception held in the daytime with a higher level of ambient in the place.

 

John Craig's suggestion to minus compensate the ambient is useful in some situations, but again, you are relying on automated responses, and I know for a fact that with the Canon flash system, you get frequent underexposures with flash, so your shutter drag margin can be thin at times, meaning you will get ghosting and blur unintentionally sometimes.

 

Also, while many photographers seem to think the well ghosted image is artsy, I would say most clients think motion blurred images are mistakes. So while I would offer some, I wouldn't shoot them all that way.

Thanks for all of the suggestions. I am still reviewing the photos I took and I realized that some of them turned out "ok." In my frustration, I had changed to Program mode, and the shutter speed was 1/60 at f2.8 for most of those that are sharp. They still show some background detail, but the tones are dull throughout the picture and it seems flat. But at least I have a starting point to go out and play until I get it right. Thanks again!

The "dull and flat" part has nothing to do with dragging the shutter and more to do with how you have your parameters set if using JPEG or how you process your files if RAW.

Thanks, I knew that the other problems were a result of "other" elements.

<p>I don't mean this to be offensive, so I hope you don't take it that way, but you need to learn how the EOS flash system works. It is, unfortunately, a topic which Canon doesn't discuss in adequate detail in their manuals, so I'm not surprised you're having trouble here.</p>

 

<p><a href="http://photonotes.org/articles/eos-flash/" target="_blank">http://photonotes.org/articles/eos-flash/</a> is the bible for this. It will explain why you got such slow shutter speeds in Av, and why you got 1/60 in P. And just about anything else you might possibly want to know about the EOS flash system. Being a bible, it's rather large and you won't be able to absorb it all in one sitting, but skim through it at least, and in particular read the sections dealing with the specific issues you encountered.</p>

Steve - and everyone else who replied! - THANK YOU for all of your insight and help. I will definitely look over the photonotes website, and much of what was being said in earlier posts is making much more sense to me the more I think about it. I am looking forward to testing changes to my settings and seeing the results. There is no teacher like experience, but you all have certainly helped!