Long Exposures with 5D Mark II ?

<p>Just bought a new 5D MarkII. It is my first digital DSLR.<br>

I used to take pictures in low light conditions in night time between 8 mins to a few hours with my film

cameras.<br>

Don't know how long can I shoot with 5D? Does battery will cover to my 4 hours shoots? Or will it go for only 20

mins?<br>

Anybody know about the time limitation with long exposure of 5D Mark II with standart battery (without extra

power grip).<br>

Thnks a lot,<br>

Sami</p>

<p> </p>

<p>And should I use mirror lock up?</p>

<p>Sami,<br>

I own a 5 D Mark II and have to admit that I never gave it any thought about the long exposures. I do not have an answer to that particular question. Seems silly to say I am sure, but it amazes me how many well meaning respondents fail to address the question asked. I do know that if there is no AC adapter available to power very long exposures that there is a battery grip available that allows you to mount either two batteries thus doubling their capacity or six AA alkaline batteries which have a pretty high current density. Of course so much depends on why you are taking such long exposures. If you are using this camera as the prime focus sensor in an astronomical telescope there are sensors made specifically for this purpose that will likely give a more satisfactory result for less money and aggravation than trying to adapt a full frame DSLR.<br>

As to mirror lock up. It is not difficult to use. Whether or not to do so depends a lot on what use you are making of the instrument. If your exposure is on the short end of long and your mounting mechanism, (tripod, sand bag ...), is not able to prevent camera shake with which ever lens you are using, longer lens more shake, then of course mirror lock up is what you probably need. If you have a very rigid configuration and a very long exposure and a physically short lens, then mirror shake is much less of an issue. Although there are those who would advocate for it in any case. <br>

If in doubt lock up the mirror check with canon for ac adapters to power your camera. If you are doing deep space astrophotography consider a dedicated ccd sensor made specifically for that purpose. </p>

<p>The problem with long exposures and digital cameras is noise - even with the 5D MKII. You will not like the results of a multi-hour exposure. When I shoot star trails I stack multiple shots and combine them in Photoshop. I take continuous 30sec. exposures over a period of multiple hours and combine those in post processing. You might be OK with an 8-10 minute exposure though - just give it a try.</p>

<p>all you need is to use bulb mode (choose "B" right next to "AV" and "M" ). i may suggest a remote trigger for long exposures. using live view to focus better (useful on low light), this engages mirror lock up<br>

im not sure how long 1 fully charge LP E6 battery will last but i usually drain my batteries playing around with bulb exposures at night and if i remember correctly i had have a few hours playing alone at night with just 15% left on my battery<br>

Christian</p>

<p>I have gone as long as 4 or 5 minutes with an XTi and 50D with no problems, using a remote release, mirror lockup, and the long-exposure noise correction feature. The latter takes a second image without exposure and subtracts the noise, so it will double the time it takes before the camera comes back under your control. I suspect you could get to 8 minutes easily. Hours, however, is another matter. That might generate far too much sensor noise to correct. I just don't have experience with that.</p>

<p>Mirror vibration is gone within a fraction of a sec so MLU won't make any difference on an 8 minute exposure. MLU is mainly beneficial with slower shutter speeds, e.g., 1/15-1/4 sec., where the aftershock may slightly blur the image.</p>

<p>Night shooting with a DSLR is a different proposition than with film. In some ways it is an improvement but in others it can be a step back. The sword has two edges when it comes to very long exposures:</p>

<ul>

<li>In favor of the DSLR is the fact that it doesn't suffer from "reciprocity failure," a situation that requires film photographers to make extremely long exposures in many situations and which can also lead to certain color shifts. An exposure that might be 10 minutes long on a DSLR could be considerably longer with film.</li>

<li>In favor of film, it doesn't suffer from increasing noise as exposures get longer - and this is an Achilles heel for DSLRs. For long single exposures on a DSLR you most certainly want to use the long exposure noise reduction feature, though this effectively doubles the time for each exposures since the camera will take a second "dark frame" exposure. (The dark frame contains only noise and hot pixel data to be subtracted from the real frame.) </li>

</ul>

<p>I've had good luck with 15 minute or so exposures and perhaps a bit longer. Some claim to have gone beyond that, though I haven't tried. There are a few alternate approaches - I'm not an expert on either but I'll go ahead and mention them in case you want to follow up:</p>

<ol>

<li>Using and automatic timer you can make a series of separate 30 second exposures separated by a minimum "dark" interval and then use specialized software to combine them into a single image. I know of people who use this to create composite exposures of many hours length.</li>

<li>I understand that some avoid the "dark frame" delay by making a single exposure with the lens cap on and somehow subtracting that data from a series of following photographs made with long exposure noise reduction disabled.</li>

</ol>

<p>Perhaps counter-intuitively, mirror lockup isn't really an issue for (most) very long exposures, since the time of the mirror-induced vibration is a very tiny fraction of the overall exposure. One exception might be, or so I'm told, is for star trails - the claim is that you might get a little "hitch" and the start of the trail when the mirror vibration occurs.</p>

<p>You might (or might not... :-) find my post on basic night photography techniques interesting: <a href="http://www.gdanmitchell.com/2009/02/11/hints-for-night-photography">Hints for Night Photography</a> .<br>

Good luck,</p>

<p>Dan</p>

<p>The 5D MKII unmodified will not give you a great pic when shooting 4 hours long. The noise would be murder. For long exposures youll want to have a cooled sensor.<br>

Example of canon mods: http://www.centralds.net/en/index.htm<br>

<img src="http://www.centralds.net/en/image/astro50d-s1.jpg" alt="" width="475" height="346" /></p>

<p>The "cooled sensor" may be just the ticket for a few very unusual photographers... but just as effective to use long-exposure noise reduction for shorter exposures or the multi-image approach for longer ones.</p>

<p>I see that I should use my film cameras for long exposure shots :)<br>

Anyway I will try 8 mins shots with my D5 MkII. But not sure about the results...</p>

 

<p>Sami, for exposure of more than 15 minutes, why not keep using film?</p>

<p>I have two different long exposure shots:<br>

1: A. Day shots with ND filters (1m longest) B: Night shots under full moon 8-10 mins<br>

2: Sky shots in the night longer than half hour<br>

I can use/try DSLR for the purpose 1 but I think I will shoot film for the purpose 2.<br>

The problem is, not much labarotories develop slides anymore...</p>

<p>Look at this program, specific for stacking images: http://www.tawbaware.com/imgstack.htm<br>

Not sure if CombineZ or Helicon Focus can also be used for night shots.</p>

<p> </p>

<p>I have the original 5D MkI and I did try a 45 min exposure. With the long exposure noise reduction it took 1hr 30min to complete the exposure. There wasn't much left in the battery after the exposure was done. The battery in the 5D MkII is different but I wouldn't expect it to go much longer. </p>

<p>As others have said sensor noise and hot pixels do become a problem in long digital exposures. For anything over a few minutes you would probably be better off with film. </p>

<p>Bob Atkins did write a article comparing <a href="http://www.bobatkins.com/photography/eosfaq/drain.html">battery life of canon film cameras</a>. There are some that basically don't consume any significant battery power with the shutter open. The EOS 600 series and EOS 1V can keep the shutter open all night and still have enough energy left in the battery for several more long nights. </p>

<p>Mirror lock up will have no effect on long exposures. The reason for this is that most of the vibration created by the mirror is gone in about 1/4 second. In low light levels that require more than a couple of seconds almost no information is recorded by the film or sensor during the first 1/4 second. </p>