frode

<p>It is not the focal length that is the problem. It is the standpoint when you take the photograph. The focal length must be small enough for the new picture to cover at least as much as the old picture. Then you scale them in post processing til the buildings fit. But you will have to stand at the same point when taking the new photograph as the photographer stood when he took the old photograph. If not, you will have changed the perspective (i.e. the relative size and position of objects in the image). Perspective cannot be changed in post (you can however change the 2D perspective of the image itself, but that will not accomplish what you want).</p> <p>You will have to use relative sizes and positions of objects in the original image (and some math, or just walk around) to find the original standpoint.</p> <p>Hope this was of any help in an interesting project.<br> Best wishes,<br> Frode Langset</p>

<p>http://www.sekonic.com/downloads/DTS_Software_Guide_English.pdf</p> <p>Page 12.</p> <p>Best wishes,<br> Frode Langset</p>

<p>OK, I now see that the newest software also can use Xrite ColorChecker (Classic, Passport or Mini) as measuring target. However, they claim the Sekonic cards are more accurate.</p>

<blockquote> <p>1- i saw several types of card for use with sekoni 758, all do the same at the end?<br /> 2- i am interested for now in get a profile for the dinamic range of my camera , what type of card i need for do it? (hoping the cheap way : )<br /> 8<<br /> 5- the calibration of my nikon for dinamic range can be done only with a grey card?</p> </blockquote> <p>You <strong>need </strong>to use one of the two types of cards that is made by Sekonic for calibrating the 758, i.e. either the <a href="http://www.sekonic.com/products/l-758dr/accessories/exposure-profile-target-for-l-758dr.aspx">Exposure Profile Target</a> or the <a href="http://www.sekonic.com/products/l-758dr/accessories/sekonic-exposure-target-ii.aspx">Exposure Profile Target II.</a> They are e-x-p-e-n-s-i-v-e, but they can be used for other tests as well. Both can be used.</p> <blockquote> <p>3- worth buy those expensive cards?</p> </blockquote> <p>Since you calibrate with finished JPEGs (either straight out of the camera or converted in a RAW converter of your choice), the calibration will only be valid for RAW to JPEG-conversions with exactly the same conversion parameters (or camera parameters for in camera JPEG) that you used when you converted the calibration images from RAW to JPEG. Whether it is worth it or not is your decision, but if you do want to calibrate you need to use one of those cards.<br /> You are asking for my opinion, and all I am willing to say is that I could see some use of it... <strong>if</strong> it had calibrated RAW images (before conversion), that is, if it was able to approximate the sensors actual dynamic range (instead of the dynamic range of a converted JPEG image). It might be that you can trick it by carefully selecting conversion parameters, but that would be tedious.</p> <p>Cheers,<br /> Frode Langset<br /> (and excuse my English, it is not my native language)</p>

<p>Hi<br> Up in the right corner you have a link to "My Workspace". Click on it. You then get to a new page with "Account options" along the right side. The first item in that box says "<a href="/community/inbox">Check your Personal Messages</a>". Click on it and you will find your messages.</p> <p>Welcome to photo.net :-)</p> <p>Best wishes,<br> Frode Langset</p>

<p>This video explains your camera's auto FP mode (high speed sync):

<p>Hi<br> The flash has a _very_ short blink time which will freeze very fast movements. Therefore you normally should worry only when you mix flash light with light from the surroundings (that is when the flash light is about as strong as the light in the environment, for example when you use the flash as a fill light). Then you have a couple of options. You can use a tripod. You can decide that only the parts that are lit by the flash will be sharp. Or you can use a flash with a high speed sync (i.e. flash that can be used with exposure times faster than the camera's sync speed).</p> <p>What to do will of course be dependent on what you want to achieve. In your example (camera says f/1.8 at 1/60th of a second), one option is to select a small aperture (say f/8) and set the camera at the sync speed (probably around 1/200th of a second). Then the light from the surrounding will not be strong enough (in your example it will be underexposed by aprox 6 stops) to be of any importance and the flash light will dominate. It's short blink will freeze movements. Parts not lit sufficiently by the flash will then be dark which might not be what you wanted. If so, you must mix natural and flash light (use slow sync) which as described over might result in blurry areas where flash is not the dominant light. Have a look here: http://digital-photography-school.com/slow-sync-flash/</p> <p>Good luck and best wishes,<br> Frode Langset<br> (and excuse my English, it is not my native language)</p>

<p>Quite interesting. Thank you.</p>