scavallucci Posted November 4, 2004 Share Posted November 4, 2004 After wasting a fair number of moon shots during the night of thetotal eclipse, I convinced myself and installed the Wasia hack inorder to get a working MLU... tonight I tested the usefulness of thisfeature.I shot a bridge at night (8sec exposure) 5 times without MLU, and 5times with MLU and a programmed delay of 3 and 6 seconds.This is an unprocessed 100% crop of a shot without MLU: http://d6d2h4gfvy8t8.cloudfront.net/2849356-lg.jpg This is an unprocessed 100% crop of a shot with MLU and a 6sec delay: http://d6d2h4gfvy8t8.cloudfront.net/2849359-lg.jpg Other interesting notes: the two 5 shot group produced consistentresults, and there is no apparent difference between 3s and 6s MLUdelay. Finally, I also tried repeating the same tests using a cheapSlik tripod, and the difference is amazing! No MLU and then MLU(6s)are here shown: http://d6d2h4gfvy8t8.cloudfront.net/2849350-md.jpg http://d6d2h4gfvy8t8.cloudfront.net/2849353-md.jpg I really couldn't be happier about the FW hack...thanks Wasia! Hope this helps,Stefano Link to comment Share on other sites More sharing options...
scavallucci Posted November 4, 2004 Author Share Posted November 4, 2004 I forgot a couple details... lens = 70-210mm f/3.5-4.5 @ 210mm and f/16 Link to comment Share on other sites More sharing options...
rayn Posted November 4, 2004 Share Posted November 4, 2004 You are not likely to see much of a difference with mirror lock-up at those speeds. Traditionally, about 1/4 of a second to 1/30 or thereabouts are where you'll need mirror lock up. Not to say it isn't important at other speeds, it's just that the effects are less noticeable. Link to comment Share on other sites More sharing options...
kiestphoto Posted November 4, 2004 Share Posted November 4, 2004 Has anybody gotten/seen CFN4 working with Wasia? I want to buy a drebel as a backup body, but I am so used to CFN4-3 mode, that it would be very hard for me. Link to comment Share on other sites More sharing options...
scavallucci Posted November 4, 2004 Author Share Posted November 4, 2004 I didn't want to check the differences at 8 second exposures, that was only a way to get easily a diagram of the camera oscillation in time (using the car head/taillights) :) I agree with you, on a 8s exposure the average light captured by each photosite does not depend a whole lot on the oscillations of the initial phase... This apparently is not valid with the shots taken with the cheap tripod though. Link to comment Share on other sites More sharing options...
mendonphoto Posted November 4, 2004 Share Posted November 4, 2004 If he wasn't using a remote shutter, the MLU could make a difference even at 8 sec - especially if the tripod wasn't very stable. A hand around the camera and finger pressing the shutter causes a lot of shake. Link to comment Share on other sites More sharing options...
jimstrutz Posted November 4, 2004 Share Posted November 4, 2004 Nick, CF#4 does NOT work with the Wasia hack. It's a great pity too. Link to comment Share on other sites More sharing options...
scavallucci Posted November 4, 2004 Author Share Posted November 4, 2004 Hi Aaron, I used the wireless Remote RC1 on the non-MLU shots... I am also a little puzzled by one thing: why does the headlight trail on the pictures looks like a composition of dots rather than a smooth line? I always assumed that during a long exposure the sensor was left for the whole time in charge accumulation mode, while here it looks like the camera is transferring the raw sensor data at a fixed rate and adding them in the system memory, resulting in loss of exposure during the sensor unload intervals ... am I just speculating? Link to comment Share on other sites More sharing options...
mendonphoto Posted November 4, 2004 Share Posted November 4, 2004 That's definitely not how a long exposure works. What you describe is a strange phenomenon. I can't explain it. Even in digital cameras, the shutters are left open for the entire time of the exposure, and the image is not recorded until after the shutters close. Pixels on the sensor continually accumulate light until the exposure is stopped (interestingly making digital cameras more "analog" than the grain in film). I'm positive of this. This is the reason many digital cameras have problems with "noise" and "hot pixels". Link to comment Share on other sites More sharing options...
smedly64 Posted November 4, 2004 Share Posted November 4, 2004 As said in the above note. Most video chipsets (CCD cameras) the individual pixels are like buckets that collect light, and at some point are shifted out to the external memory. In video it may vary from 15 to 1000 transfers per second. In single frame CCD imagers (telescope varity) it is also true you set the requirement and it stores then dumps the values to the external memory. I thought your images with dots was odd. When I have used my D300 in a similar mode I get a line not dots? Link to comment Share on other sites More sharing options...
ron c sunshine coast,qld,a Posted November 5, 2004 Share Posted November 5, 2004 Some obvious suggestions first just to get them out the way- <BR>Were you shooting through railings or a fence? Was the road bumpy Link to comment Share on other sites More sharing options...
scavallucci Posted November 5, 2004 Author Share Posted November 5, 2004 No, I shot from a deck but the camera was above the railings. Also, the bridge has been resurfaced few months ago and it's very smooth... Over the weekend I'll run some more experiments with different ISO, exposure and aperture. Link to comment Share on other sites More sharing options...
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