And again about photographing the moon with improvised means

The text was written as a supplement to the previous post and, in part, as a report on his own experience with the use of improvised means. Thus, this opus does not contain the slightest hint of ultimate truth and is intended for geeks who are not looking for shop solutions. The justification of the posting with duplicate content in some sense is only that about a dozen advantages were put under the proposal of the author of the mentioned post to me to issue a separate post. So they asked for it themselves .

Weekends were spent searching for used equipment and photographs (both electronically and on paper). Even if the post is not interesting to anyone, it turned out to be useful to me — along with my family, I was surprised to find many interesting photos. But I got distracted.

It was in 2003 and at my disposal was the recently purchased Canon G3 digital soap dish with a 4/1 / 1.8 "Matrix format (7.2 x 5.3mm). It is clear that even at the largest equivalent focal length (140mm) the Moon didn’t work :


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The size of the moon is less than 60 pixels, and I wanted to noticeably larger (in fact, it should have been one and a half times larger, but when shooting the example found now in the archives, the resolution was set to 1600 x 1200 instead of the maximum possible 2272 x 1704). None of my acquaintances had a telescope, but there was a mirror-lens objective of MS MTO-11, which I decided to use:



Everyone will say that it was necessary to fasten it to the SLR and not suffer. This, of course, is true, but we recall the date and make sure that the first budget Canon 300D SLR has not yet come out, and everything else was significantly more expensive. In addition, I wanted to do everything with the help of already available funds. The diameter of the image of the Moon, created by MTO-11, was about 10 mm. It was necessary to force the soap box to re-shoot this image, i.e. arrange a stronger macro than was available. The benefit of macro photography experience with the use of an inverted lens already had:



For this, an optical scheme with a second inverted lens was used:



A 50mm lens flipped to the object with a “film” side projects the image of the object to infinity, and the lens of the soap box focuses the image from infinity onto the matrix. In such a scheme, the zoom (shooting scale) is equal to the ratio of the focal length of the main lens to the focal length inverted. The lens was attached through a reverse ring of 58mm-49mm (reverse-adapter) to the adapter for attaching filters, which is standard for the camera used.

Since a suitable astrofoto is impossible without sustainability, we had to make an adapter, which allowed us to firmly combine a hedgehog, a snake and other animals. A certain amount of turning work, a bit of finishing the rasp to the rocket, and here is the result:



Project participants:

1. MTO-11
2. adapter M42-M42 in order not to spoil the thread MTO
3. the first part of the adapter (ends with thread)
4. the second part of the adapter with grooves for the protruding parts of the lens and the fixing screws with gaskets
5. 50mm / 1.7 lens (inside the adapter)
6. 58mm-49mm wrapping ring
7. standard for used camera adapter for mounting filters
8. digital camera

The focusing of all lenses is infinite, and the adjustment in field conditions was done by shifting the hard block soap dish + lens relative to MTO (implemented through rotation of part 4 relative to part 3 on the thread). A brief explanation of the optical circuitry enclosed by the garden : the MTO forms the image of the Moon, the 50mm lens turned over by the “film” side projects this image to infinity, and the lens of the soap box focuses the image from infinity onto the matrix. A heavy tripod was used, on which the MTO was fastened with the additions hanging on it. The survey was conducted from a prone position in a snowdrift away from the houses, until the hands were frozen, or the goblins' attention was drawn.

Let's finally see what this hybrid engineering masterpiece is capable of:



Converted jpg medium compression maximum resolution (2272 x 1704), pixel size - 50% of the source. To heighten the quality, we should, of course, shoot raw (the camera allowed), but that is. The result is pretty good.

A few years later, it was found that a similar idea was used for video shooting with a shallow depth of field at a time when the matrixes of cameras had small dimensions and gave, respectively, a greater depth of field. The difference was the presence of a frosted glass on which an intermediate image was created: a DOF adapter .

And finally, some more examples of the photographs obtained:



Now, of course, it is much easier to remove the moon with a good resolution: there are soap dishes with a giant effective focal length, there are relatively inexpensive (albeit not with the current course) SLRs with low-noise matrices, you can use a Barlow lens or a teleconverter to increase the pixel size (the Moon is about Three times smaller than the size of a 35mm frame when using a 1000mm lens), although the list of affordable lenses is small. But, as I said above, the equipment available then challenged, which was accepted and, good or bad (judged by you), the shooting was implemented in reasonable accordance with the rule of proportionality of the complexity / cost of the components included in the system.

Having finished the post, I remembered that I had a desire to photograph the moon while still in junior classes.


After reading the text again, I realized that the boom post lacks the main thing, that is, the seals:




I hope it was interesting, or at least liked the photos. If there are questions, I will try to answer and add text if necessary. Thanks for attention!