This article is divided into four parts, in which it is fully shows the shared discussion forum from 20 February 2014 to a 9 June 2014, with the glorious completely manual realization by “Massimar”, a mirror Newton diameter 300mm focal ratio F 3,8 with excellent quality of surface roughness given by peak / valley on the glass less than one-sixteenth of the wavelength (Lambda) of 560 nanometers of yellow-green light that the human eye is more sensitive, corresponding to an optical quality of at least lambda / 8 reflected wave.
All this of course respecting the all-important Couder criterion, which states that (..in order to get the perfect canonical diffraction image giving maximum quality and contrast in the images provided by the telescope that will mount that mirror), the reflective surface of the mirror must be such that all reflected rays converge within the "diffraction notch" (also called Airy radius), which in fact, for the mirror in question, is a little disk in diameter 2,6 thousandths of a millimeter (microns) which is located at the distance of 2280mm by the mirror itself, equal to the focal length of 1140mm.
The teaching and educational importance of the discussion, for those who want to have an excellent example of how it carries out a good optical work, It is absolutely made unique by the wealth of detail in the description, both budgeted corrective actions from time to time, and that the results (good or bad) obtained, from the fixes made to finalise the processing of that superb mirror.
The importance cited is coming from the fact that all the numerical data given here, are all you need which can be profitably typed within any program for evaluating the Foucault test, in order to study and active testing of the variations of the shape of the mirror surface, until its fulfillment.
Part 3 of 4
Re: Parabolizzazione mirror 300 F 3.8 Great GIULIOT, I do not know what I had tried that information on the internet finding very little…I now have a better idea and above all a tool for comparison with other Partine…:ok: |
Re: Parabolizzazione mirror 300 F 3.8 For capacities. With a bread from a kilogram of Gugolz 55 I made a tool for the 300F6 and 250F5 a tool for the advanced and I still tentatively for at least another 200mm. Calculate it for my tools I realize, with a silicon mold, of pitch candy from 20x20mm thick x10mm….so do not thin. |
Re: Parabolizzazione mirror 300 F 3.8 Great Giuliot ! :ok:, all this “mine” of procedures is subject to the use of more specific Gulgoz, or they are also applicable for the vulgar rosin ? p.s. I do not know if it happens to you: if they are logged in can not display some images in the post Giuliot, but only to previews, if I get disconnected instead is nancy… |
Re: Parabolizzazione mirror 300 F 3.8 Realizing the “seniority” one of the previous link I gave you, (maybe now no longer works) and which it refers to the comparison between hardness of the natural pitch Gugolz and that of Acculap brand “synthetic”; I am attaching a link to download from my “google drive”, the PDF copy of the same document that I hold for some time…(otherwise permissible is extremely rare). @massimar: In reference to the use with the rosin, to obtain hardness of the pitch parameters: I would say that I, personally I would use my Gugolz 55 (because I already have, and if I had I procurerei bread) to make a penetration test with ball. Try that then I would use for comparison. following, I would put in my old pan, 650g of rosin flakes (that is just part of that abundance that had very kindly provided me with good Reginato, with the purchase of my blank Ø250 pyrex, I requested specifically thickness of 28mm). Those 650 g (if you are correct volume calculations and the specific gravity) They are sufficient with good margin, for covering a tool diameter 300mm, a layer continuous pitch 10mm thick. Obviously in the casserole add also NOT 11.5% by volume (example Texereau)… but, for example, 8% of castor oil; and stirred it well preleverei a quadrotto be cooled in water and try the ball, as a comparison “all’americana” with the hardness of Gugolz 55 ….(…taking into hot on the electric stove thermostated at 60 ° the saucepan with lid) I realize that this does not guarantee anything. Ma, making a more general discussion of Growth, I would only point out that….The questions you ask will you today, I have made me the day before yesterday… NON… potendomi give (alone) acceptable answers, e, for this, even today I I learn from you things that I had no way, nor time to groped to learn by myself in the past. P.S: (the Gugolz 55 for me is excellent in winter, ie up to 17 ° C ambient… Why in summer ” you live” …and I do not need the pastime “Gym maintenance of muscle tone”, which it is precisely de “scratching glasses” ;)). |
Re: Parabolizzazione mirror 300 F 3.8 I started with Foucault and Ronchi tests although they are still far from the parable, I should be roughly in “halfway” A shameful the focal length of the mirror measurement error :spaf: that accurately measures 1130 mm and not 1120 as reported in precedeti test, hence the focal ratio returns to be the starting: 3.80 I omit to say why I did wrong because there's really no shame :D Run sessions only with past W with sub-diameter 125 mm lasting 20-25 me. approximately fifteen.  Click to enlarge http://s26.postimg.cc/wmqq27b4p/R21.jpg Readings Foucault tester : zone 1 = 0.05 report:  Click to enlarge http://s26.postimg.cc/b1lnelee1/F21.jpg As you can see the road is still long, But it seems to be progressing smoothly… at least I hope ! |
Re: Parabolizzazione mirror 300 F 3.8 massimar for parabolizzare with sub-diameter you have two solutions: flatten a circular crown on the edge or vice versa deepen the center. The easier and controllable solution is usually the second. One method is to start with a small tool, working mainly in the center and around it, using past COC with limited frittering, alternating sometimes of planetary over the entire surface in order to avoid the edge ribattutto, that still, probably, It will still be generated, although rather sweet. The epicyclic also restricts the formation of “zones”. Obviously, the edge is then retorted always removed with the sub-diameter, using the method of localized pressure. It then proceeds with larger tools trying to standardize the parable, But mostly working outside the center. As usual, always check your progress frequently. To make more precise work the patina should be changed reducing the part of the surface of the edge tasseli, cutting them with a cutter. |
Re: Parabolizzazione mirror 300 F 3.8 the “quantity” Information contained in the post astrotecnico It is increasing in inverse proportion to the unused space, then an increasing density that will always require more time to be well understood. At this rate we will see the birth of the first “singularity” in a forum, where all knowledge is contained in one word resulting in an infinite time for its understanding. :) Sorry astrotecnico, I'm joking, and as always I thank you for your great availability and for all the valuable lessons, the fact is that then the techniques mentioned by you, to be sought ( if you are ), including tried and tested, and as you can imagine it is never easy, especially for a novice, be sure you have got it right and do the right thing. passed epicyclic: since there are endless ways to design an epicycle in a circular area, I went to seek , overseas typing “EPICYCLIC stroke parabolizing mirror” but I found nothing… The methods for a localized pressure for the elimination of retorted edge, I hope that when if the need arises, do you mean someone, considering that (at least on this ) It is everything, but also the opposite of everything, indeed, there are many self builders who claim to have found the best method for solving this problem. ( obviously all different methods from each other ) reduction in the area of part of the dowels to the edge: Also here there are many procedures described for the tool change ( until
“stella”, until
“triangles”, until
“margherita” etc..) , even some manufacturers recommend making all parabolizzazione with past COC, modifying the surface only at the edge of the tool, so that the material removed at the center is greater than that removed in the periphery as a function of the contact surface, which is calculated according to the parabola to achieve. So a technique that should be studied in detail, with indications of those who have already experienced, to hope to get some results. There would be many other questions I get from reading your interesting posts, but if someone had an answer for these, It would be a great help. |
Re: Parabolizzazione mirror 300 F 3.8 You do not know how I am with you when you say d`accordo “especially for a novice, be sure you have got it right and do the right thing”…'I am there almost always doubt…:) |
Re: Parabolizzazione mirror 300 F 3.8 It actually my post is a bit’ too terse ! Now I try to clarify ……. passed epicyclic: this has passed for me a form, let's say so, petals. Imagine doing a series of circular past interlinked with each other, closing on itself this series. I'm talking about some past, not many. localized pressure: This is normally used operating system for tools in general, where a guide hand, the other applies pressure. Elimination of the edge ribattutto: you're right in saying that there are many ways to do it. Obviously also the sub-diameter are suitable for this use, applying the pressure required, which must be consistent. We will see in detail how, But I think you've already guessed. Reduction of the surface of part of the blocks at the edge the pitch: look closely at the movie beginning G.Waite (T= 35 seconds) and notes as well as he cut the pieces to the edge. In the audio commentary explains it very well and I must say that despite being an American does not speak a very narrow slang, enunciating the words ! |
Re: Parabolizzazione mirror 300 F 3.8 Thank you astrotecnico,:ok: and to think that after finishing 125 mm thought I had seen most of what there was to see on the optical processing :spaf:, It was just the tip of the iceberg ! I do not know how many other disciplines are so closely related to the knowledge of other, here you go by mathematics, optics, materials technology, chemistry, the physical ( and the cabal because luck is always useful ..) I say to take away a small pebble in the shoe, to those who argue that it is a kind of tedious and repetitive work, of the kind ” I do not I could never do because I have all this patience” , in fact, patience is one of the last requirements that are used to this type of application. |
Re: Parabolizzazione mirror 300 F 3.8 Your 125 It can not be that pure basic exercise, as indeed it is also a 300F5. |
Re: Parabolizzazione mirror 300 F 3.8 A bit’ irons in the fire… When I built my network for the Ronchi test I printed on glossy paper, a series of lines made with CAD thick 0,25 mm, which meant ( in my opinion ) 4 lines for 1 mm , that is, a black line 0,25 + a white 0,25 + a black 0,25 + a white 0,25. This thing is important, because changing the number of lines in the various software setup, graphic simulation changes accordingly, and why with is also the 125 mm previously worked, it based only on Ronchi, I went “long”… With Foucault, I became aware of this aspect, now all back even crossing the results between Foucault and Ronchi, whereas with the previous setting the result is that analyze with a double number of lines compared to the actual ones on its lattice, It is equivalent to doubling the value of the conic constant. Returning to parabolizzazione, I went ahead considering that the last analysis showed that there was still to be excavated in the middle , I adjusted the past trying to apply what I had previously been told by astrotecnico, I hope you understand it:  Click to enlarge http://s26.postimg.cc/yklho07q1/stroke_z1.jpg then with the sub 125 mm to also align with the area 3 in this way:  Click to enlarge http://s26.postimg.cc/uzpm4s36h/image.jpg The following are some sessions with classical past in W always with the sub 125 mm. Results of tests Ronchi:  Click to enlarge http://s26.postimg.cc/gconn44k9/image.jpg Foucault test with values calculated on the average: 0.13 2.12 3.88 5.78 7.35  Click to enlarge http://s26.postimg.cc/sftzaofmh/report3.jpg What now? He pulls down the edge so if you go over you return to the sphere ? P.S. The ML chart contains an error ( at least it seems ). I do not know why but printing out the screenshot of the ML chart values are halved: On the software I see this chart, which it is also consistent with that of Modas and with the spreadsheet of Giuliot:  Click to enlarge |
Re: Parabolizzazione mirror 300 F 3.8 Hi Massimo. I see you progress well. The “Zig Zag” always part of the game. My network of Ronchi (which it is then the slide with a pattern from 5 and one from 10 linee/mm, present as an attachment in the book “notes optical astronomical Luigi Ferioli), presents, in what he 10 linee/mm , a width of blacks traits 0.05mm. Indeed printing of your millies-la croix is always wrong in so unrealistically optimistic. |
Re: Parabolizzazione mirror 300 F 3.8 hello Giulio, perhaps a typing error, I think you mean 0,05 mm for the width of blacks traits, quite right ? And, Also it seems to me that I am doing the correct way, but now that the “scissors” He begins to shrink, the effects of any correction seem to be amplified and spend more time to decide what to do that in the actual machining, for fear of doing the wrong thing. What would you do ? :) |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
In fact, It is my typo, and the right figure is 0,05 (I also corrected the message) Quote:
If the HX data on the windows of your Couder mask (67-94-116-134-150) they are correct, putting your drawdowns of Foucault, in my excel sheet, I would do the following considerations: 1) I see first of all that the area 4 It is at the moment a minimum point, already low at the limit (current) not grattabilità, and leave it to rest. For example: Sconfinerei scratching in the area 2 (But scratching less) bringing it to a draw 1.8 (in F13), which would mean scrape 29.8 nanometers high. (detected by the difference between the before and after the blue graph) Sconfinerei still in the area 3, but much more slightly, bringing the draft 3.78 (in g13), taking away only about 13.5 nanometers high.. 4) Arrived up to here, I would put in the box D24, an experimental value that I find around 1400. A value that the graph of green background, It aims to correctly orient your curve, until it touches at a point on the red or green dish, and on the other in two points facing, which their mutual distance expresses the peak-to-valley mistake of your curve (hence the Lambda). 4) At this point you would find with a nice dish to lambda / 3, and you'd just want to touch up the area salient 5, the only report to the fold, remained outside the reflective diffraction notch, proceeding to scratching with a light hand. See how they did it?… I have an inclination for the simulation game and the dream ...(But fortunately these are dreams that depend only on us). |
Re: Parabolizzazione mirror 300 F 3.8 Since I wrong :spaf:, I would have also modified the 4 , to me it seemed short ! one thing important, I forgot to mention, the exact values of the rays of the areas calculated with CouderMask : the effective diameter, net chamfer is 297 mm, therefore the rays of zones : I believe, however, that the analysis should not change much. |
Re: Parabolizzazione mirror 300 F 3.8 Change actually slightly:  Click to enlarge http://s3.postimg.cc/5ubqnnucv/Foucault297_F1130.jpg Realizing the draft values in area 1 of -0.5 (that is -0.68 compared to the current reading); in zone 2, di1.8; in zone 3, of 3.85 (AS STATED IN THE PREVIOUS POST) accrue for already a surface with lambda 4, without touching the area 5, whose reflection still would fall out of the diffraction notch (then not optimal contrast ....). To have a superlative mirror you should drag FINALLY, inside "TRUMPET" of Millies-Cross tolerance (that in my excel is the graph in yellow background), also the area 5, grattandola with all due caution to avoid “game over” with return to the sphere, to bring it to a draft of not less than 7.62 At the end of this hypothetical adventure, you would have a value of lambda 7,8, obtained WITH ALL 5 ZONE reflective INSIDE…. the diffraction notch. By entering to form an image with a considerable contrast non plus ultra. (I would still be improved ... but personally I would NOT be the case going to put "kicks ass in" .... as they say my dear friends Trentino. Is’ this; regardless of my very personal ruminations; a prospective setting of your work on a 3.8 F…., I assure you…among the best that we can hope!! :ok: |
Re: Parabolizzazione mirror 300 F 3.8 …..I forgot to invite you to replace in the Excel sheet, the various drawdowns hypothetical proposed for each zone, starting with the first to be changed. I, in my normal insecurity in this field, I draw much benefit from these simulations, that help me to experience things, then I can never make as I had speculated…But that lead me still very close to the simulated goal.:ok: |
Re: Parabolizzazione mirror 300 F 3.8 Thanks Giulio, ! :ok: I'm trying simulations, as you suggested, which actually make it a better idea of what you should do. I have not yet clear the relationship between the amount of material removed and the effect on the curvature and then draw on the values. Another unclear issue is the reliability of the readings, after two or three sessions of measurement, the readings “stabilize”, in the sense that I always get the same results, the maximum difference that match than the first is of the order of 1/10 in mm. ( on the central areas ). demand from 1 million $: there is a way to evaluate and quantify the error “subjective”, ?:rolleyes: |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
At first your lower Zoina was 2; lowering the area 1, 2 e 3, The lowest area becomes a temporary lack 4, but only until you correct the 5. After all the hypothetical operation, you would find with a lambda 7.8 but again with a zone 2 that touches under. |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
In fact, matter before the operation, is then go to see to what degree moves the point in the graph of the glass to be removed. Quote:
No. But to my knowledge, (I am referring to parrot what is written in the sacred texts) by a certain curvature no longer spherical, on, you could replace the method of Foucault with that said caustic of reflection, which it seems less subjective, and more precise, of which I have little knowledge. On this particular topic it would certainly be illuminating the thought of Astrotecnico. |
Re: Parabolizzazione mirror 300 F 3.8 Giulio, I was studying your repeating simulation start, e ( casually ) I face that just changing the values of the area 2 e zona 5 bringing respectively 1,8 e 7,7 leaving the other unchanged, a thing happens very very interesting ..:D  Click to enlarge http://s26.postimg.cc/rl3au9zbt/ITA…_Su_5_zo.jp g But how does one “shorten” only the area 2 without touching the other ? |
Re: Parabolizzazione mirror 300 F 3.8 the catch is …:spaf: or shorten a radius should PUT glass….while working you can just take off. To back “to grow up” the glass in an area, must lower all the other. really sorry, why the “glass missing” in zone 2 that would make you splash the Lambda value of the stratospheric 1/16.6, It would be very little…..If you think about what could be its thickness, to ensure that the focal point of that area, going to fall 32 CENTS mm, more towards the center of curvature !!! Is’ a little like going to the ball, in the sense that we need to work throughout the rest of the figure, so that the deficient part against the rest, riemerga. With my modest experience, I'm not surprised, however, that there was some interesting trick, but I do not know. OTHERWISE simulations are used just to browse in the vicinity of the position where it has come, and where possible find the unexpected shortcuts. |
Re: Parabolizzazione mirror 300 F 3.8 and at this point I'm usually a bit’ in confusion, in the sense that for me is shorten a beam to think that you can do it, also increasing the curvature in that area , then removing material from the median area of the sector. But I already know that does not work, although I have not figured out why… :or |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
Your idea is right. But part of the difficulty is practical, and it is in the tool size in relation to the width of the annulus to be corrected only in the center. In some of these cases there are descriptions of how to use tools, directly thumb; doing a regular spiral movement in the previously well demarcated area with a permanent marker daring much “rich cream” cerium oxide (or zirconium, or qel that is). No hurry, in the sense that we must not rest for next to nothing, and verify to the course at each revolution of the table. Certainly a brave but timid proof perhaps you can….Have you ever seen that does not suddenly solve the situation ? |
Re: Parabolizzazione mirror 300 F 3.8 another evaluation… :hmmm: If one observes the general trend of the curve, and then Ronchi, you can see that about half the curvature radius of the lines increases, This makes me think of a central hole that still is not aligned with the rest of the surface. A mid-range we are the inner boundary of the area 2. The curvature of the exchange “hole” shortens the focal length of the area 1 compared to 2 and increases the overall draw. Foucault tells us to go to the parable should increase the curvature of the area 2, putting the two together, it means ( in my opinion ) there is to “smooth” the edge which is formed between the central cavity ( the hole ) and the remaining surface.  Click to enlarge http://s26.postimg.cc/o8044oc2h/image.jpg In this way , uniforming the curvature, you should have a first effect reduction the value of the overall draft and also the draw between the first two zones as the hole increases the curvature only to the first zone, while the remaining surface is still under-correct, We can stand ? |
Re: Parabolizzazione mirror 300 F 3.8 Of course you can stay, because in any case we see Foucault “of small scale”, the areas defined by the rigid mask Couder..che maybe you are right “mounted” of the offending area, and they do not see the exact beginning and end of an interesting phenomenon. While the Ronchi instead, He sees things together. Your reasoning then row….And at worst, from close checks you will do, you can always fix. In all ways I think I would keep a discreet amplitude reduction of the treated area, working very slightly and with tool size a little smaller than the area to be treated, and making a check in each round table. (The “bello” of this phase always very weighted processing, It is that you can not spoil anything permanently :)…Except…. its stoic resistance :or !! |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
Well, thanks Giulio, then this evening I would start with this procedure attack: sub 60 (ashtray ) with light localized pressure at the center to apply with past court ( tangential ) within a crown of a crown of rays 60-100 mm ( to the edge horse ) per 2 rounds of table.  Click to enlarge http://s26.postimg.cc/mvif2semx/stroke_z2.jpg COC sub-125 to even ( few ) following, depending on events, Repeat the procedure if necessary, or some’ Healthy victimhood in the forum with a new post titled “back to the ball in Part III ” :) …….. At this point I feel I have to give some advice to those who, perhaps reading these pages, or other discussions in the Forum, be tempted to embark on the road optical dell'autocostruzione: do not do it, unless you have the confidence to rely on the support and guidance of someone with years of experience and also on the cooperation of “scratchers colleagues” and share experiences and compare the problems, because contrary to what may seem, It is not a way to go solo, It must be part of a “crew” with expert surfers to ride, without which you will not get anywhere. I was convinced before and they are even more now, why every time I thank all those who make available to others their experience, small or large, with intellectual generosity, in full agreement with what should be the philosophy of a Forum. Who started this path alone, relying on its own strength and its ability to learn definitely has a natural talent , but this , Unfortunately, not my case… :hello: |
Re: Parabolizzazione mirror 300 F 3.8 What can I say ....: I confirm that as you say ... ..magari would experience almost no pressure ..., because, in addition to your considerations, I, by reckless illiterate in matters, taking the excel spreadsheet with the data of your drawdowns 0.13 – 2.12 – 3.88 – 5.78 – 7.35, I see by the blue graph the boundary between the area 1 e 2, it's tall 64.9 nanometers high.; while, the value replacement 2.12 with 1.8, this height leads to 36.7 nanometers high.. Which means that they should go into operation, 49 nanometers high. (... that is the crazy amount of 0.049 microns !) to bring already to an approach of the two limit parabolas, such as to bring the lambda to 4.7 |
Re: Parabolizzazione mirror 300 F 3.8 So, just for the hell of theorizing, I think that by acting in the way that has been said and eliminating the “edge” consequently we will also have eliminated the excess curvature of the area 1. The next step should be to resume digging the central areas, while maintaining their relative distances up to bring them back to the right fit with the outer zones, is that, to recover 0,4 mm draw “eaten” previously. At this point you should end up very close to the situation that you have simulated. All this with the obvious premise that could've said a roundup of hogwash :) |
Re: Parabolizzazione mirror 300 F 3.8 Predictions about the parable figure based on the finishing touches, They are like those weather….They are good only in the very short. |
Re: Parabolizzazione mirror 300 F 3.8 Stò following long,beginning of the discussion,this beautiful adventure of the process of parabolic mirrors ;I must pay compliments exaggerated the strength of will and the time spent in different stages of lavorazione.Certo is that it's also a great satisfaction and pleasure ,I think,both the processing that the final result,when this was a beautiful mirror and supercorretto lucidato.Non hide some envy but I hope one day to have time to venture with a nice touch of glass to work,indeed I hope presto..per now I follow the tread …:hello: |
Re: Parabolizzazione mirror 300 F 3.8 weather update: good weather does not rain ! I made only two sessions of corrections planned due to an unforeseen event ( I'll tell you later ). In fact the results are in line with forecasts, not equal but the trend is to shorten the relative drawdowns at least until the absorption of the central cavity.  Click to enlarge http://s26.postimg.cc/jox2an8yh/Picture_1043.jpg Measurements: 0.35 2.20 3.85 5.45 7.30  Click to enlarge http://s26.postimg.cc/ym5jbnm6x/Tes…04_14_zone.jpg The incident is blown out observing with attention Ronchi test: Taken from a “terrible suspicion”, I put the mirror on the tube and went into the garden to look at Mars: the small planet disk is presented with the sharp edges , but with a view “ghost” slightly on the same disc, as when it is observed with binoculars not perfectly collimated, moreover this “elongation” changes direction passing from intra to extrafocal. It was already that I had a few days of this notice “distortion” on rhonchi, Surely sessions to standardize the surface were not sufficient to eliminate the errors zonal of working with sub-diameter. So I did not insist further with corrections and I went to see the goals from Cristiano Ronaldo of Italy 1 :D |
Re: Parabolizzazione mirror 300 F 3.8 Ciao morfeo, thanks on behalf of all “grattavetro”, we hope to have you soon among us :hello: |
Re: Parabolizzazione mirror 300 F 3.8 @Morfeo: As far as I'm concerned…(I maybe I cover the role of the famous “Talking cricket” that this is an adventure of Massimar) What you say is a safe undeserved compliment. The trick that underlies the realization of a mirror Newton, It is to understand even “broadly” the “steps forward and backward ones” to do for the generation of the dish with the glass scratching. I say "Broadly" because then you always find yourself in a similar condition to that of the conquest of a beautiful girl seemingly unattainable ...... This is to say that doubts will always be present, and Decision, it will be necessary to follow other corrective aiming purposefully ...... BUT ... ..avendo understood the general sense dell'antifona ... remains only an excess of adrenaline to be disposed of in the course of the adventure. However, ALL adventures are harbingers of adrenaline, although in a different way. The beauty of this is that while Massimar and Deabis scratch, I'm doing as Jiminy Cricket, but even without having absolutes, except , at my back, modest experience in the production of three mirrors without being able to take advantage of the benefits of sharing problems, offering a Forum….(And today, contrary to the rest of the world, continue to be counted on the tips of two fingers SUN those who are currently in Italian amateur glass scratching). Then there is the adrenaline for me ... but it's positive as fatigue; chilli and red wine in the diet !! |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
So be:D Quote:
You overestimate me boy!!! To me it is only in mind the possible double reflection by the rear mirror wall!! Quote:
So you must do!! :ok: Apart from anything else, I see that the center (dropping the edge that faces last) It is still high, so maybe enlarging the middle of your ashtrays share for a round or two of table, It could lead counsel (…I hope easily increase the lambda) |
Re: Parabolizzazione mirror 300 F 3.8 Quote:
So I would… PINOCCHIO ?! Well, I hope at least to meet the Blue Fairy :cool: anyhow, for me this is an adventure team, alone I would not go anywhere, in my mirror I put the material we work, but to my mind it is minimally, I would not even done 125 mm without the support of the “cricket” Giuliot, the guidance of “master Geppetto” astrotecnico, and the comparison with both “the cat” Deabis e “the Fox” bart, which with their associated rich threads of valuable tips and experiences. Rather, what I wonder is who will never Eater :hmmm: Quote:
I hope not ! because the fact that you have not mentioned that word ( ugly ) ast that starts and ends up igmatismo, that is my ancestral fear that I can not even appoint in full, leaves me hopeful… |
Re: Parabolizzazione mirror 300 F 3.8 I would be confident that the effect of that word (which begins with my provincial capital)…you would do with Ronchi….So I would be optimistic about. |
Re: Parabolizzazione mirror 300 F 3.8 Indeed !, This is exactly what I said, it seems to me that the Ronchi is distorted, It is not symmetrical, It seems made in Pisa, It hangs on one side ! The defect observed in a visual to tele, It could be a fire ast… ? |
Re: Parabolizzazione mirror 300 F 3.8 Could… |