Search found 165 matches

by Bushman.K
Wed Jan 20, 2016 11:15 pm
Forum: Equipment Discussions
Topic: High CRI LED source?
Replies: 14
Views: 7354

They claiming CRI 98 and color temperature up to 5600K for VTC series emitters, which doesn't sound realistic, because even top manufacturers don't offer anything like that - high CRI currently means "warm white".
by Bushman.K
Thu Jan 14, 2016 6:26 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Continuous light vs. flash?
Replies: 7
Views: 2175

I'd like to describe my own experience here. Usually, portable constant light sources are associated with relatively low power. Technically, to get acceptable short exposure time faster than 1/200, you need a light source which is equivalent to 100W incandescent lamp or even more powerful one. But c...
by Bushman.K
Wed Jan 13, 2016 12:47 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Downsizing and effective aperture
Replies: 28
Views: 4611

You are right about microscaling and the majority of downscaling methods. Even if you would pick some method, which will produce the same brightness profile as original image have, it doesn't mean it preserves real details. It just re-creates the same amount of contast. Speaking of your conclusion r...
by Bushman.K
Wed Jan 13, 2016 11:16 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Downsizing and effective aperture
Replies: 28
Views: 4611

So, here are "sharpness diagrams" derived directly from your images by wavelet decomposition, extraction of highest details level, contrast maximization and application of color lookup table to it for better appearance: https://habrastorage.org/files/a83/dcf/13e/a83dcf13e86645bb961cce6a809a30ab.png ...
by Bushman.K
Tue Jan 12, 2016 5:29 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Downsizing and effective aperture
Replies: 28
Views: 4611

I'd just insist on mentioning certain difference between "lower resolution sensor" and "downsampling". Because downsampling is quite diverse, from Least squares method which makes an image always super-oversharpened to B-spline method which actually preserves certain blur: https://c2.staticflickr.co...
by Bushman.K
Tue Jan 12, 2016 4:40 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Downsizing and effective aperture
Replies: 28
Views: 4611

While it's always possible to speculate about "effective DOF", "effective diffraction limit" and so on, if I were developing some sort of terminology for describing this situation, I'd always use "system, limited by ..." term to describe it in general. All games about reduction of image resolution m...
by Bushman.K
Mon Jan 11, 2016 1:23 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Processing and Hosting Video Clips
Replies: 6
Views: 1845

For certain tasks I'm using VirtualDub, which is completely free, but not really friendly, if you need to stitch fragments. Getting rid of unwanted parts, transcoding, stabilization and other things are much easier to use. Another editor I'm using from time to time is NCH Software VideoPad, which is...
by Bushman.K
Sat Jan 09, 2016 3:21 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: 5DsR/MPE65 useful magnification experiments
Replies: 8
Views: 6458

To expand Rik's explanation just a bit, I'd say that in general case, sharpening with global methods is useless because it obviously amplifies both useful details and noise. Local sharpening, limited in some way, does its job better. Sharpening, applied after certain "smart" noise reduction also wor...
by Bushman.K
Wed Dec 30, 2015 6:40 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Lighting for macro photography of fern gametophytes
Replies: 600
Views: 159063

Technically, specular highlights don't have to be produced with the same light source used for filling the scene. You can use large high power diffused source of any kind as your main source and another light with point source, several times weaker, to form specular highlights. You will still have t...
by Bushman.K
Thu Dec 17, 2015 2:17 pm
Forum: Equipment Discussions
Topic: New 5X APO Objective with Unknown Mount Any Advice Needed
Replies: 16
Views: 3596

Just in case, for about $6 you can always get yourself a pitch gauge which helps a lot to clarify thread parameters.
It's not a magic thing, but it helps.
by Bushman.K
Thu Dec 17, 2015 10:52 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: check before stack ?
Replies: 5
Views: 1558

There are different ways to visually check images (for example, you can use free IrfanView in thumbnail mode in addition to those tools mentioned above). But there is no simple way to check images automatically because of how diverse they are. In general case, image statistics (histogram shape and u...
by Bushman.K
Thu Dec 17, 2015 12:20 am
Forum: Equipment Discussions
Topic: New 5X APO Objective with Unknown Mount Any Advice Needed
Replies: 16
Views: 3596

0.05mm difference per thread × 4 threads = 0.2 mm which is about 1/4 of single thread width. For me, it sounds like M34×0.75 thread will not go into M34×0.70 thread deeper than two turns. So, I wouldn't recommend it. Ordering from Moscow, Russia will likely take 4+ weeks for delivery (keeping in min...
by Bushman.K
Wed Dec 16, 2015 3:17 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Tabletop setup for stacking at oblique angles
Replies: 9
Views: 4092

RRS equipment is good, but overpriced, considering production costs.

And yes, political contributions of RRS owner can have certain significance to people.
by Bushman.K
Wed Dec 16, 2015 1:02 pm
Forum: Frequently Asked Questions (FAQs)
Topic: FAQ: Assessment of empty magnification using GIMP
Replies: 13
Views: 16702

FAQ: Assessment of empty magnification using GIMP

Every optical setup intended for macro or microphotography has own limitations in terms of magnification. For example, setup with lens, set on macro bellows can be effectively used within certain extension length only. Longer extension gives larger image, but amount of details visible in it stays th...