Search found 7817 matches

by ChrisR
Thu Apr 23, 2009 12:33 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

You want the mass at the sensor (ie as near as possible), so the shutter energy moves it minimally. The wood is lightweight and springy, and the table is miles away compared with the distance between the shutter and the sensor. I don't see it doing much to stop the sensor moving - we're only talking...
by ChrisR
Wed Apr 22, 2009 11:33 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

IN the first graph, with mirror lock, those are the shutter tremors. On the Richter scale on the right which is barely readable, they're both 14-18k units, which compare with the shutter vibration on the other camera. Lower, where "zuruck" normally means "back", so I assume dropping back, there's a ...
by ChrisR
Wed Apr 22, 2009 1:14 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

Dave - that doesn't SOUND too difficult to test :D
At say 1000th second exposure with a camera with a 250th flash sync speed using minimum overlap. I reckon you'd see the effect of the first curtain closing, 3/4 of the way through the exposure. Agreed?
by ChrisR
Wed Apr 22, 2009 1:00 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

Rik -SO it is! I would have expected the exposure-ending part of the process to be much the easier to achieve electronically - just ignore the outputs from the sensor, before closing the curtain. So perhaps we'll see changes in the future. The live-view shutter on a D700 is a crash-bang-wallop affai...
by ChrisR
Tue Apr 21, 2009 10:57 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

There is probably a magical window of shutter speeds where the virbration causes significant problems Well the German post shows the highest peaks in the first 50th of a second, with a half-life of around 1/10th of a second. So the shutter spoeed chosen, 1/20th , is obviously a good one to use. Rik...
by ChrisR
Tue Apr 21, 2009 2:23 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

mgoodm3

Any idea what you'd get if you used flash and a darkened room?
Chris
by ChrisR
Mon Apr 20, 2009 3:36 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Speed Test for Zerene Stacker.
Replies: 15
Views: 7508

try downsizing by 2X, so that you're working with images of size 2.1k x 1.5k pixels.
You meant :D 4x, OK I'll try that.
It appears I can go up to 3GB for about $50 though, so that has to be the way to go!
Thanks for the advice.
by ChrisR
Mon Apr 20, 2009 1:14 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Speed Test for Zerene Stacker.
Replies: 15
Views: 7508

Oh dear, I do apologise Rik, being dyslexic I avidly check spelling but the numbers slip by. "reduced in PS to 100 wide" Should have been 1000 wide, ie 1000 by about 666. And you guessed right about the 4.2 x 2.8 = 12Mpixels. The good news is that using today's update and PMax I got a very good resu...
by ChrisR
Sun Apr 19, 2009 9:06 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Speed Test for Zerene Stacker.
Replies: 15
Views: 7508

Running Pmap with scale set at 15% instead of 5% because I moved the lens to focus at about mag3 - 4 , subject about 6mm deep, and got multiple images when the last 15 or so images were processed (when image size reduced in PS to 100 wide) Letting it go with 4.2k x 288k images, "Thread 6, out of mem...
by ChrisR
Sun Apr 19, 2009 4:22 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Measuring camera vibrations
Replies: 60
Views: 17723

AS it happens I have load cells, optical tranducers and a couple of oscilloscopes about the place, but using a laser the obvious thing to do would seem to me to get it shining (attenuated) back into the camera, or at least onto something the camera can see. With a little thought a magnification of t...
by ChrisR
Sun Apr 19, 2009 3:27 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Speed Test for Zerene Stacker.
Replies: 15
Views: 7508

My old 2.67Ghz P4 with 1GB ram took well over an hour for 5 x 4200 x 2800, which is about 0.5 Mppm. I only got through the 115 images in the stack by reducing each one to 1000 wide. ZS was slightly slower than CombineZP, but not enough to matter. Using more jpeg compression didn't make much differen...
by ChrisR
Sun Apr 19, 2009 9:10 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: B & L fiber optic/ flash setup
Replies: 65
Views: 26648

I'm looking for a properly tapered plastic bottle Well I'm not going to give you Mrs Ballcock's number :twisted: I'd try a lens with a large entrance pupil to see how much better it made things than just putting the fiber up against the flash head. Either with a flash meter, or your SLR and a piece...
by ChrisR
Sat Apr 18, 2009 1:28 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

I reckon I've read all the posts, hereabouts and their quotes from historical external references. Whether I've understood them is another matter... To paraphrase; Use a smaller sensor... ... put on a lens that is half as long, set it to the same f-number, and take another picture. ... to make the "...
by ChrisR
Fri Apr 17, 2009 11:53 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

I'm reserving judgement on Depth of Field. What Rik et al are saying, feels wrong! eg As a photographer , I care about the f number. I don't give a stuff what the iris measures. I care about how fuzzy the image is on the print, not about what size the sensor was at an intermediate stage between the ...
by ChrisR
Thu Apr 16, 2009 4:59 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Like a kid on Christmas day
Replies: 9
Views: 4820

They always said your best photos were in your head, between the time you took them and when you developed the film. My best idea for cheapskate macro is in the same abyss. A Cokin filter holder, eg at http://www.cokin.co.uk/photos/extring.jpg That shows one with extension rings , which I've never s...