chimray Posted February 23, 2011 Share #1 Posted February 23, 2011 Advertisement (gone after registration) Now thinking to buy this Len, can you guys give me some comments 1. Uv ir filter: is it a must for m8.2 ? Also this filter is a special one in 77mm which only place in a special ring, cannot place in the square hood. 2. Viewing angle: something like 67- 100 degree, not really understand this If some can post pictures from this Len using M8 or M8.2, it will be great Link to post Share on other sites More sharing options...
Advertisement Posted February 23, 2011 Posted February 23, 2011 Hi chimray, Take a look here 18mm F3.8 in M8.2. I'm sure you'll find what you were looking for!
ho_co Posted February 23, 2011 Share #2 Posted February 23, 2011 1) All lenses for M8.2 should use UV/IR-Cut filter to avoid effects of the high IR sensitivity of the body. Nonetheless, not everyone uses them. 2) Field of view from Leica's technical data: Diagonal = 84° Horizontal (long side of M8 frame) = 74° Vertical (short side of M8 frame) = 53° Does that help? (I don't have the lens and can't post pictures from it. The forum's search function might help you find pictures made with it.) Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/144825-18mm-f38-in-m82/?do=findComment&comment=1596998'>More sharing options...
chimray Posted February 23, 2011 Author Share #3 Posted February 23, 2011 Tks and it help but honestly not so understand for pt.2, I need to digest more, tks:D Link to post Share on other sites More sharing options...
ho_co Posted February 23, 2011 Share #4 Posted February 23, 2011 Chim, the camera makes a rectangular image. The diagonal of that rectangle runs from one top corner to the further bottom corner. With this lens on the M8, the angle ("field of view") encompassed across that diagonal, measured from the camera, is 84 degrees. Similarly, the height of the frame (short side) as seen from the camera encompasses 53 degrees. And the width of the frame (long side) as seen from the camera encompasses 74 degrees. So if two objects on the ground in front of you are 80° apart, the field of view of the lens isn't wide enough to catch them with the camera held horizontally. (80° is wider than the 74° angle that the lens sees.) On the other hand, if the angle between the two objects on the ground as seen from the camera is 70°, the lens will be able to record both in the same image. (70° is less than the lens' 74° horizontal field of view.) Link to post Share on other sites More sharing options...
chimray Posted February 23, 2011 Author Share #5 Posted February 23, 2011 Thanks Howard to give me a lecture, I need time to understand all these:o Link to post Share on other sites More sharing options...
marknorton Posted February 23, 2011 Share #6 Posted February 23, 2011 For the M8 and M8.2, Leica have a neat UV/IR solution which is a shameless copy of the solution we developed here for the WATE. It's much better than using the huge filter ring and filter though is only suitable (and needed) for the cropped sensor cameras. You can use the standard hood which comes with the lens. The rangefinder coupling on this lens is not great and relies on the deep depth of field this focal length/aperture combination provides to dig itself out of trouble. Link to post Share on other sites More sharing options...
hoppyman Posted February 23, 2011 Share #7 Posted February 23, 2011 Advertisement (gone after registration) Wolfgang from the Leica Akademie loaned me one to try with the M8 Customer Service loaned me while mine was being upgraded. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/144825-18mm-f38-in-m82/?do=findComment&comment=1597176'>More sharing options...
ho_co Posted February 23, 2011 Share #8 Posted February 23, 2011 Geoff-- To give Chim an idea of the angles of view involved, do you recall about how far from the nearer headlight you were? Link to post Share on other sites More sharing options...
hoppyman Posted February 23, 2011 Share #9 Posted February 23, 2011 Well, this is a crop but I would have been around 2-3 metres away, from memory. The idea was to provide a practical example of course. I think the most useful number would be that the 18mm gives a horizontal angle of view (from left to right) of 90 degrees. Most people can picture that, I think. On an M8 that is a little cropped of course. The actual figure then is 74 degrees. I think easy to hold out your arms to make 90 degrees to picture that angle. Just pull them in a little for the M8 Looking at that another way, on the M8 it is like shooting with a 24mm lens on an M7. For general comment I found it easy to handle, not too big or heavy and with low distortion, excellent definition, contrast, colour rendition etc as you would expect. Stopped down a little it is truly excellent. The ZM Distagon (Zeiss design) is also very good in my experience. On the M8, the focal length lets you easily produce dramatic effects by deliberately choosing a close or low view point. http://www.pbase.com/hoppyman/image/101813580 http://www.pbase.com/hoppyman/image/101824431 http://www.pbase.com/hoppyman/image/130777816 At the same time works reall well for landscapes etc without any gimmicky fisheye type effect. http://www.pbase.com/hoppyman/image/131263464 Link to post Share on other sites More sharing options...
ho_co Posted February 24, 2011 Share #10 Posted February 24, 2011 Chim-- Does Geoff's explanation make better sense to you than mine? (I hope.) If not, what part are we failing to clarify? Link to post Share on other sites More sharing options...
chimray Posted February 24, 2011 Author Share #11 Posted February 24, 2011 Thanks Howard and Geoff, know I may understand a bit more, why I rasied this question is when I surf the web, see the len comparsion, why in Zeiss 15/2.8 only show 1 viewing angle and Leica 18mm show a range, see attachment. Geoff, your pcitures is nice in Zeiss 15mm, so what is yr comment for this len compare to Leica 18mm 3.8 ? Compare Zeiss Distagon T_ 2.8_15 ZM and Leica Super-Elmar-M 18mm f_3.8 Asphe.pdf Link to post Share on other sites More sharing options...
ho_co Posted February 24, 2011 Share #12 Posted February 24, 2011 .. see the len comparsion, why in Zeiss 15/2.8 only show 1 viewing angle and Leica 18mm show a range, see attachment.... Ah, now I see! You'd have to ask the folks at Camera-Catalog why that's the case. Anyway, for the Zeiss, that's the diagonal (which defines all the others via the Pythagorean theorem). I've got no idea why they show a range for the Leica lens. That's highly peculiar. Maybe it would be better to get information directly from the manufacturers' own sites instead of from third parties. Remember also, the numbers they're quoting are for full frame 35mm, so both lenses would show less on the M8 because of its crop factor. I haven't used either of the lenses, but I don't think I've seen anyone complain about either. The 15mm Zeiss is wider and almost two stops faster, but it's also quite a bit heavier. You'd need to look into getting a UV/IR-Cut filter for the Zeiss; it might be even clumsier than with the Super-Elmar. Link to post Share on other sites More sharing options...
chimray Posted February 24, 2011 Author Share #13 Posted February 24, 2011 Thanks Howard, u are a morning bird to reply so earlier Link to post Share on other sites More sharing options...
marknorton Posted February 24, 2011 Share #14 Posted February 24, 2011 The angle of view of a lens is: 2 * ARCTAN (d/2f) Where "f" is the focal length and "d" is the sensor size. For the M8, the sensor diagonal is 32.45mm so with an 18mm lens, the diagonal angle of view is 84 degrees. Use 27mm as the sensor size and the horizontal angle of view is 73.73 degrees, rounded to 74 degrees. Note too that the foqcal length is not exact and the angle of view will vary slightly as the lens is moved away from the sensor to focus closer. Link to post Share on other sites More sharing options...
LeicaMSeattle Posted February 24, 2011 Share #15 Posted February 24, 2011 Great lesson on basic geometry! Link to post Share on other sites More sharing options...
beewee Posted March 5, 2011 Share #16 Posted March 5, 2011 Little late but I have this combo along with the UV/IR and screwmount filter holder. I actually bought the UV/IR filter about 8 months after getting the lens so I've shot with this lens quite a bit, both with and without the UV/IR filter. Whether you absolutely need the filter or not depends on your subject. If you're shooting people with dark synthetic clothing, you'll want the filter to avoid the magenta cast. Also, if you're shooting vegetation, you'll also want the filter to avoid a olive green / yellowish cast on foliage. The field of view of the 18/3.8 on the M8.2 is the equivalent of a 24mm on full frame so if you've ever shot full frame with a 24mm, that's what you should expect. It's a fair bit wider than looking through the 24mm framelines on the M8.2. If you don't already know yet, you'll also need to budget for a viewfinder. I personally went with the Zeiss 25/28 finder. Even though the frame lines are a bit narrower than the actual field of view of the 18/3.8 on the M8.2, the viewfinder (to me at least) is brighter, has distortion and is cheaper than the leica counterparts. I've also tried the Leica wide angle zoom finder but found that the edges were blurred in the sense that you don't have clear cut edges of the frame and found it quite annoying. If you're patient, you can find used Zeiss finders for around $300 or maybe less if you're lucky. Link to post Share on other sites More sharing options...
AbbeyFoto Posted March 5, 2011 Share #17 Posted March 5, 2011 I use the same combination as beewee. I too like the Zeiss finders but there is not a tight match of the 25mm frame to the 18mm / M8 combination. I bought the UV/IR filter with the lens. Be warned it is expensive but well made. You can use the lens hood with this filter but the hood does not give great cover for the filter and so you need to careful with oblique sun light catching the filter. I like this lens a good deal. Not done proper tests but I suspect it gives more colour saturation then other Leica lenses. Chris Link to post Share on other sites More sharing options...
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