Search found 581 matches

by soldevilla
Sun Jan 13, 2019 4:21 pm
Forum: General Discussion Forum and Community Announcements
Topic: searching a formula for a barlow
Replies: 8
Views: 3359

Many thanks, Rik. This is a big help for me.

Thanks again
by soldevilla
Sat Jan 12, 2019 12:24 pm
Forum: General Discussion Forum and Community Announcements
Topic: searching a formula for a barlow
Replies: 8
Views: 3359

searching a formula for a barlow

Many years ago I used a simple formula that allowed me, knowing the diopters of a negative lens and its position before the focus, to know how far the resulting focus is away. As in a telescope barlow ... I know that maybe it is not an issue of this forum, but I think that here there should be frien...
by soldevilla
Sun Dec 30, 2018 3:06 pm
Forum: Equipment Discussions
Topic: Schneider 28mm f2.8 Componon Perf Stacked is Extremely Good
Replies: 32
Views: 5768

Hi. What is the optical design of your assembly, Robert?
Macro Symmar is focusing to infinity and then you superimpose the Componon? It is assumed that an enlarger lens works best when the distance to the focus from the front and back is short ...
I already have some tests to do next year.
by soldevilla
Tue Dec 04, 2018 10:37 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: someone knows this objective?
Replies: 9
Views: 4039

I expect youhave this - see P57: http://www.science-info.net/docs/leitz/LeitzImageForming-IlluinatingSystems.pdf "DO" means "with or without cover glass". (So it's not the same as mine) this objective will be filled with dust in the drawer. Be careful, they breed . I put two lenses like that in a d...
by soldevilla
Tue Dec 04, 2018 2:51 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: someone knows this objective?
Replies: 9
Views: 4039

Nothing, I have tried everything I have and I do not get any major improvement. I have discovered fun things, as using a photographic duplicator between the lens and the camera. I expected that I would not get any image but yes, there is image and it is not especially bad; or place it in front of a ...
by soldevilla
Mon Dec 03, 2018 11:55 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: someone knows this objective?
Replies: 9
Views: 4039

I´ve found my projection eyepiece. I have unmounted it for cleaning and i have found that it is a very simple Huygens eyepiece :smt089 . I go to test an Ortho. Is the same design but both lens are a achromatic group. PD. I have tested a 12,5mm eyepiece. Too much! only 0,2mm of field. I think I have ...
by soldevilla
Mon Dec 03, 2018 5:55 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: someone knows this objective?
Replies: 9
Views: 4039

Thanks. I not have a Periplan eyepiece, but I own a lor of eyepieces for telescope. I will try some of them.
by soldevilla
Mon Dec 03, 2018 2:47 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: someone knows this objective?
Replies: 9
Views: 4039

someone knows this objective?

The first lens I bought is a Leitz 170 / - L20 0.32 with integrated iris, some years ago. I have not used it too much because I prefer the Nikon, but this Leitz has the advantage that the cylinder measures just 10mm and allows me to illuminate my samples much better. but it always shows a chromatic ...
by soldevilla
Mon Dec 03, 2018 2:37 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: gold, again
Replies: 2
Views: 2645

gold, again

New minerals in my collection. It is very curious, and incomprehensible to me, that the same objective produces results so different according to the nature of the object photographed. These two photographs correspond to the same sample (in fact, they are less than 5 mm apart). The "lettuce" (really...
by soldevilla
Thu Nov 29, 2018 11:39 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Kasolite
Replies: 3
Views: 2674

Hi JL. Now I'm not in my house. The only thing I have is this link with the analysis.

Salud.

gr-mulhacen.foroactivo.com/t2402-kasolita-sierra-de-cabo-gata-nijar-almeria-andalucia-espana
by soldevilla
Tue Nov 27, 2018 1:01 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Negative copier
Replies: 12
Views: 3402

I read once that the resolution numbers offered by the scanners and printers are indicating the accuracy with which the head is positioned. In the case of the mtuell scaner, it could be indicating that the mechanical position of the head is very close to one thousandth of a millimeter (it is very li...
by soldevilla
Tue Nov 27, 2018 12:03 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Negative copier
Replies: 12
Views: 3402

I wonder if so much resolution is really necessary. I photograph my negatives with a simple Canon 1100D and I have already solved the photographic grain, so using more resolution will only get to better define the grains. I have a 6 * 6 camera and a 9 * 12cm camera. When I go back to my house, I am ...
by soldevilla
Mon Nov 26, 2018 12:54 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Kasolite
Replies: 3
Views: 2674

Kasolite

Kasolite is a "new in Spain" mineral that I have honored to take images for publishing it. It is very small, and I need to use the Nikon x40 objective for to obtain this one. I'm out of home, taken images of archeological items, and I have used for our forum the picture issued in Facebook. I hope it...
by soldevilla
Fri Nov 23, 2018 3:28 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Self-adhesive flocking in long tubes. Aaaaargh!!
Replies: 35
Views: 13332

I have used since I can remember for all my photography and astronomy accessories the cheap black velvet adhesive sheet that they sell for young people to line their books. If it is used only with its adhesive, the sheet peels off after a short time. I paint with contact glue (I do not know if this ...
by soldevilla
Thu Nov 22, 2018 12:31 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Negative copier
Replies: 12
Views: 3402

I think not... this is the negative http://www.photomacrography.net/forum/userpix/1389_color1_1.png Now, Ctrl+A, Ctrl+C, Ctrl+N, Ctrl+V Take a sample of color from the bottom edge with the dropper, outside the frame, and paint the new image with the paint bottle tool. And now Apply image, subtract o...