Talk:Single-lens reflex camera

message: The term 'reflex' has nothing to do with reflection by a mirror.  A reflex camera is one where the image is focused onto a ground glass plate for viewing before exposure.  This image can come from a viewfinder lens as in a TLR, or through the imaging lens as in an SLR.  Note that modern digital cameras where the imaging sensor is used to display the image on an LCD viewfinder are not technically reflex cameras.  This article is a technical mess.
73.177.133.8 (talk) 19:09, 14 November 2015 (UTC)
replies: text: The term 'reflex' has everything to do with a mirror.  A camera that focuses directly onto a ground glass screen is not a reflex camera. TLRs and SLRs have mirrors, so they are reflex cameras.  And yes, agreed, sensor viewfinders are not reflex cameras. It's not clear what point you're trying to make here. Groogle (talk) 02:14, 5 January 2021 (UTC)
thread_title:  Reflex? 

message: SFLDID cameras are different than SLR and should not be connected. 64.222.211.140 (talk) 17:27, 8 March 2011 (UTC)
replies: text: "Prior to the development of SLR, all cameras with viewfinders had two optical light paths..."
SRL cameras also have two light paths. The correct distinction is the number of lenses.  —Preceding unsigned comment added by 76.119.143.94 (talk) 15:51, 12 January 2008 (UTC)
thread_title:  Definition? 

message: Difficulty in constructing wide-angle lenses because of the space-consuming mirror movement.
My question is: Wouldn't a telephoto lens require more space due to its greater focal length, than a wide-angle lens (whose focal length would be smaller)? Isn't the article's comment reversed on this? (Or am i missing something here?)
This is right. The problem is that at infinite focus the center of the lens should be at a distance of the film plane that is equal to the focal length. This mean that a 100 mm telephoto will have its center at 100 mm from the film while a 28 mm wide angle will at 28 mm only this doesn't leave enougth space for a moving mirror that should be around 24x36mm for a 35mm camera. For illustration have look at http://cameras.alfredklomp.com/jupiter12/ the Jupiter-12 is a very basic WA design for non-SLR camera and look how deep the rear element goes into the camera. In the fifties they were no WA for 35mm SLR while 35mm were alvailable for Leica. The solution is to use a retrofocus lens. This design allow the lens to have a distance from the film that is longer that its focal length, it's like two lens packed the first one forms the WA image and the second focuses the first image on the film. Obviously this is complex design thus expansive and prone to more aberrations. Retrofocus designs are sometimes called "inverted telephoto", because you can roughly reverse the design to build short (I mean physical size) telephoto lenses. For instance you may find a bit bulky a 300mm lens that will at least 300mm long with a basic design. A telephoto design will allow to build a lens shorter than 300mm. Ericd 00:53, 25 Jun 2005 (UTC)
thread_title: Other Questions

message: The K1000 is a notable camera, IMO, because (a) it started the K mount and (b) it was very successful in terms of sales.  Yes, it didn't introduce any real technical advances, but that's not in my opinion the only measure of notability.  Comments? Matthew Brown 09:36, 17 November 2005 (UTC)
thread_title:  K1000 

message: As i know the advantage of SLR camera is for able to see the exact sean through eye piece (avoids parlox error). Now all digital cameras shows the exact picture on the screen. Then still what is the importance of the SLR camera's. Please some one clarify.
:A digicam screen eats batteries and is very hard to use in bright sunlight. Also the resoloution of the small LCD display isn't sufficiant to use for anything more than selecting the frame area (can't really be used to manually focus or to check the autofocus has got it right). I have a screen only digicam and its pretty horrible to use compared to a camera with a traditional viewfinder. Plugwash 00:29, 26 February 2006 (UTC)
replies: text: In addition to the above comment, I would like to say that an SLR viewfinder is usually brighter, clearer and the image more defined than is the case for an LCD screen. There is no eye-strain, as would be the case with continued viewing of an LCD screen. I will say that one of my digital cameras, the Canon PowerShot G7, has a fine LCD screen and when I don't want to carry a D-SLR, this camera is surprisingly good. I wish, however, that the camera had a real wide-angle capability as the lens is the 35mm camera equivalent to a roughly 36 to 210mm camera lens. I would prefer, say, a 24 to 85 35mm camera equivalent, or even wider.--MurderWatcher1 19:55, 5 September 2007 (UTC)
thread_title:  Impotance of SLR camera in this digital era. 

message: I don't know how to include this but when a rangefinder gets autofocus it lost its rangefinder and become a basic viewfinder camera... See Konica Hexar AF or Contax G. Ericd 15:54, 6 December 2005 (UTC)
replies: text: These cameras should be considered as rangefinder cameras only and not included on this page. Sorry for the long-awaited response!--MurderWatcher1 (talk) 23:12, 7 December 2007 (UTC)
thread_title:  Rangefinder vs. Reflex 

message: I contribute mainly to the french wikipedia and worked recently on the french version of this article. It uses the same cross-section picture (as do many other international Wikipedia's). Recently, someone stated that this picture is wrong, that it shows a wrong number of reflections in the prism. Personnaly, I seriously doubt it and would rather think that the US, DE (etc...) articles are correct. Only this user reverts every time I remove his comment. So I guess I need some extra sources to convince him (or maybe he's right after all, who knows?). I made some search but found nothing except copies of this US wikipedia article on other websites...
Does someone may an extra source/reference then?
The only (small) critic I have against this picture is that it doesn't show inverted rays after the lens, but it's not treally the point of this article to explain the way lenses work. As a side note, I got the same problem (with the same user) with the picture illustrating a roof pentaprism, so I asked a similar question in the "Talk" page of this article. --Jérémie A. 13:12, 28 February 2006 (UTC)
thread_title:  Is the cross-section correct? 

message: The diagram does not show the aperature. It would be nice if it was included.
Erland Lewin 14:33, 28 February 2006 (UTC)
replies: text: The aperture is irrelevant to the concept being shown, and adding an iris diaphragm would be an unnecessary complication. -- Hoary 11:16, 2 March 2006 (UTC)
thread_title:  Aperature 

message: What's the difference between SLRs and SLR-like cameras? All that I can tell is that SLRs don't come with a lens (?), and SLR-likes do. 71.250.17.62 02:01, 20 June 2006 (UTC)
replies: text: found some information at DSLR 71.250.17.62 15:49, 21 June 2006 (UTC)
thread_title:  SLR-like 

message: I have just removed this very recent addition: Filters that attach to the end of the lens only increase the options for the  photographer. The most commonly used is a UV filter, which is extremely useful for reducing the harshness of sunlight in a picture.
:The first half is true, and also true of various alternatives to the SLR. (Indeed, it could be argued that a red filter is a major pain with an SLR but a breeze with a rangefinder camera.) The second half is simply untrue. -- Hoary 13:22, 12 October 2006 (UTC)
replies: text: The correct wording of the first paragraph should be: "Filters that screw into (typical 35mm SLR's) or bayonet onto (Hasselblad lenses) to the front of the lens". You can, in some lenses, insert filters into the rear of the optic, such as certain mirror lenses such as the 500mm f/8 reflex Nikkor Super Telephoto lens; or some fisheye lenses. There are also some interchangeable lenses with built-in filters.--MurderWatcher1 15:16, 7 September 2007 (UTC)
thread_title: Filters

message: Respectively questioning the usage of the double arrows around the word <<intelligent>> in the first sentence of the “Autofocus” section. Is there a meaning to this or just an oversight? Just a Wiki-rookie trying to help! Bigwig77 01:52, 2 January 2007 (UTC)
replies: text: Thanks for catching that. I've replaced the guillemets with double quotation marks. A non-native English speaker probably added them by mistake. --Imroy 05:02, 2 January 2007 (UTC)
thread_title:  Guillemets 

message: Wouldn't Paul1513's recent additions be more appropriate in History of the single-lens reflex camera? --Imroy 02:24, 2 May 2007 (UTC)
replies: text: I just saw this. However, we do have some history already in this Wikipedia reference so, anyone else want to 'weigh-in' on this topic?--MurderWatcher1 20:19, 7 September 2007 (UTC)
thread_title:  SLR chronology 

message: In many SLRs there's a circle at the center of the viewfinder that splits the image, shifting some to the left and some to the right unless the image is in focus. What is the name and mechanism this gadget? —Ben FrantzDale 01:04, 2 November 2007 (UTC)
replies: text: It's called a split-image focusing screen. Most recent SLR's (digital and film) have a plain screen without the split-image focusing aid. I guess manufacturers think it's unnecessary now with autofocus being so common. Replacement screens can be purchased though, e.g   (I'm not affiliated with Adorama in any way, I simply found it with a Google search) --Imroy 02:42, 2 November 2007 (UTC)
replies: text: The 'canonical' manual focus focusing screen involved a focusing matte covering the entire viewing area, with a central split-image prism surrounded by a microprism collar.  All three were useful for focussing in different ways.  The modern autofocus SLR has a very fine matte screen and no other focusing aids.  The coarser the matte, in general, the more obvious the 'snap' into focus is, but a coarse matte reduces light transmission.  Since an AF SLR generally loses a portion of light to autofocus and metering, because cheaper SLRs have less efficient pentamirrors rather than pentaprisms, because most SLRs come with a slow kit zoom rather than a fast prime these days, and because reduced format digital SLRs have less light to play with anyway, it's less desirable to have a screen that doesn't pass the maximum amount of light. Matthew Brown (Morven) (T:C) 07:56, 2 November 2007 (UTC)

text:  Thanks. I added a request for more technical detail to Focusing screen. —Ben FrantzDale 03:52, 3 November 2007 (UTC)

text: I believe Herbert Keppler and some others referred to this focusing collar in the center of the screen as a split-image rangefinder. As —Ben FrantzDale has said, there are many types of focusing screens and you have to find the particular one that is useful to you. When I purchased my first Nikon F SLR, I wanted the type 'F' focusing screen, which had a microprism collar. I really wanted the 'E' at the time but that lacked the microprism and was just a straight fresnel screen, with grid lines, so that you could use this for architectural and landscape photography. Maybe do a search on these if you want more information.--MurderWatcher1 (talk) 23:22, 7 December 2007 (UTC)
thread_title:  Split focus thingy 

message: "To avoid the noise and vibration, many professional cameras offer a mirror lock-up feature, however, this feature totally disables the SLR's automatic focusing ability."
I think this is misleading. Canon dSLRs do the following when set to use mirror lock-up:
1) Focus when the shutter is half-depressed
2) Flip up the mirror when the shutter is fully pressed
3) Open the shutter
4) Close the shutter
5) Lower the mirror
The autofocus works the same as when not using mirror lock-up.
--Ilnyckyj (talk) 01:59, 15 November 2009 (UTC)
replies: text: What you described sounds like normal non-mirror-lock-up mode; don't you need a second button press at least?  The point is that once the mirror is up, you don't get to autofocus again before the second press. Perhaps you can clarify that. Dicklyon (talk) 06:37, 15 November 2009 (UTC)
thread_title: Mirror Lock-Up

message: In the History section, the description of the Olympus OM2 is correct - "Olympus The 35 mm film-based Olympus OM-2, which was the first SLR to measure light for electronic flash at the shutter curtain". But the photo is of the later OM-2SP/OM-2 Spot-Program model, which was not the first. A photo of the original OM2 is needed (I have an OM-2N, which I could photograph, and that would be better - but we really need the original OM2 to accurately show the first model with that feature) -- Boing! said Zebedee 10:03, 5 April 2010 (UTC)
thread_title: Wrong photo