Search found 7817 matches

by ChrisR
Sat May 02, 2009 4:28 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Stacking software issues…
Replies: 7
Views: 3184

Thanks for that. It's difficult to find previous discussions because all the keywords are so widely used.
by ChrisR
Sat May 02, 2009 4:16 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Live bug photography made simple.
Replies: 4
Views: 2480

If you remove the wire cage, what's left to retain the bugs? I admit to possessing an electric flyswatter, like http://en.wikipedia.org/wiki/Flyswatter#Electric_flyswatters. They were reduced from £30 to £5. It produces a few hundred volts, with enough energy to make your skin jump. I tried it twice...
by ChrisR
Sat May 02, 2009 2:56 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Stacking software issues…
Replies: 7
Views: 3184

Things are always easy to do when you don't know how to do them and therefore don't know what you're talking about. I've looked around the web but haven't found much about stacking methods, like pyramid or Dmap, so at the moment it looks easy. :D SO then, one simpleton's approach: Start at the front...
by ChrisR
Sat May 02, 2009 7:45 am
Forum: Equipment Discussions
Topic: Canon MPE65 on a Nikon Body?
Replies: 21
Views: 7025

Just not any NEW brand! It seems a shame when there are so many excellent lenses in the EOS family.
by ChrisR
Sat May 02, 2009 4:22 am
Forum: Equipment Discussions
Topic: Canon MPE65 on a Nikon Body?
Replies: 21
Views: 7025

It's a MF lens, so it doesn't need a helicoid. The thing I haven't found how to do - though it's probably out there somewhere, is electrically stop an EOS lens down when off the camera. It'll probably be a voltage, or a current, or a pulse, or a series of pulses. None of which would be hard to gener...
by ChrisR
Sat May 02, 2009 3:48 am
Forum: Equipment Discussions
Topic: How to repair damaged threads on microscope objective?
Replies: 14
Views: 6878

Er, Artful Bodger here. Not finding am RMS adapter cheap and easy to get hold of I cut a hole in a plastic microscope lens case - the ones where you screw the lens into the cap. With its base flattened a bit, and stuck to a body cap with a hole also cut in it, I'm sorted until I find something bette...
by ChrisR
Thu Apr 30, 2009 2:24 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

There would not be much point in producing a 50 megapixel sensor if the lenses you could put on it could only resolve 25 megapixels at full aperture! That assumes lenses resolve x lines/mm and stop at x + 1. But as MTF curves are designed to show, it depends on contrast. If you look at a lens test ...
by ChrisR
Tue Apr 28, 2009 5:50 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

Yes certainly it has (I spent more time than was good for me poring over spotty pictures from crystals of doped silicon and a TEM. Usually looking at "Stacking faults" which has a certain resonance... :o ). Those are linear(/square) with size, so we're seduced into simple sums. "All other things bei...
by ChrisR
Tue Apr 28, 2009 5:07 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

Nikon's productions of late have provided some comparisons, on the D3/D3X vs D2/D2x Full frame 12Mp sensor shows less noise than the smaller 12Mp ones, and less than the later full frame 24Mp sensor. But the 24Mp sensor does get more resolution out of a good-enough lens. As I mentioned above, the Ni...
by ChrisR
Tue Apr 28, 2009 3:30 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

Rik - Aggression - behavior aimed at causing harm or pain. Well of course that isn't intended and I apologise if that is felt. I can understand that you might perceive your point of view not being accepted as being aggressive, but that isn't intended. The basic technical matters aren't in question. ...
by ChrisR
Tue Apr 28, 2009 2:05 am
Forum: Equipment Discussions
Topic: Canon MPE65 on a Nikon Body?
Replies: 21
Views: 7025

Elf - there's nothing in Nikon's range which is good for magnifications of say up to 4 times, in the field. A reversed 28mm is usable, but with adapters (especially with a double cable release) it's a bit of a handful. I don't know anything about EOS bodies, I suppose some of them must be cheap, but...
by ChrisR
Mon Apr 27, 2009 2:07 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

it is simply not true that using a smaller sensor will give more DOF Well, I disagree, because when you use the camera with the smaller sensor everything changes. Just starting with the lens. To pluck just one aspect, pixel noise went down when Nikon developed the F3 sensor (full frame but still ab...
by ChrisR
Mon Apr 27, 2009 1:26 am
Forum: Equipment Discussions
Topic: Canon MPE65 on a Nikon Body?
Replies: 21
Views: 7025

OK Charles, so if I glue a Canon rear lens cap to a Nikon body cap, what DO I do with those pesky electrickery bits? Are the specs of the camera-to-lens connections for any of the manufacturers published, anyone :-k I can see me buying a bashed-up AF Nikkor just to see what the connections do. One f...
by ChrisR
Sun Apr 26, 2009 5:03 pm
Forum: Equipment Discussions
Topic: Canon MPE65 on a Nikon Body?
Replies: 21
Views: 7025

Canon MPE65 on a Nikon Body?

Could this be made to work?
I don't know how the Canon auto-diaphragm mechanism works. Presumably the lens could be fixed in the stopped-down position?
There seem to be many adaptors for N lenses to fit EOS bodies but not vice-versa :?
by ChrisR
Sun Apr 26, 2009 4:04 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Final (?) thoughts on sensor size and magnification
Replies: 49
Views: 12293

I've pondered this for a while now, and I know how I feel about it. It's a philosophiocal thing, really. The maths isn't in question, never has been. I worked things out as many of us would, when first able to apply school stuff to lens geometry. The tests referred to provide nothing surprising, the...