rahul_deshpande1 Posted November 29, 2004 Share Posted November 29, 2004 Hi All, I received my OM-1N fom KEH today and I noticed something wierd... When I attach my 24/2.8 lens on it, I can see a huge vignette with only a small circle of the field at the center of the viewfinder. This does not happen with my 50/1.4.Does this have something to do with the focusing screen? It is not a split image diamond pattern screen like the one in my OM10. Rahul Link to comment Share on other sites More sharing options...
preston_merchant Posted November 29, 2004 Share Posted November 29, 2004 Sounds as if the depth-of-field preview button is engaging and the lens is stopped down. What do you see when the lens is at 2.8? Link to comment Share on other sites More sharing options...
mark_bouquet1 Posted November 29, 2004 Share Posted November 29, 2004 Just a guess, as I've never experienced this, but it could be that you have a screen optimized for extreme telephoto lenses, or for extreme macro work. There'll be a number on the tab of the focusing screen when you remove it. (Wash your hands first and do not to touch the screen except at the edges or tab. Better yet use the tool supplied for the purpose, if you can get one.) With that number, you can look the screen up on the web or post the number here, and someone will tell you what it's specifically for. Link to comment Share on other sites More sharing options...
rahul_deshpande1 Posted November 29, 2004 Author Share Posted November 29, 2004 Looks like I have a 1-12 Cross hairs/Clear field screen. I looked it up on http://brashear.phys.appstate.edu/lhawkins/photo/om-screens.shtml It is used mainly for photomicrography or greater than life-size macrophotography. If you guys can look up the link, am I right to assume I would need a 1-3 split image/matte screen? Rahul Link to comment Share on other sites More sharing options...
lex_jenkins Posted November 29, 2004 Share Posted November 29, 2004 Yup, that focusing screen is optimized only for specific photographic uses. For general purposes with most lenses you'll need one of several other OM screens that are readily available. Some folks also swear by the brighter (and more expensive) Beattie screens. Link to comment Share on other sites More sharing options...
kieran_hamill Posted November 30, 2004 Share Posted November 30, 2004 Lex is right. You wont be able to discern DOF effects and focus snap with that screen, but with a 24mm lens it will not be too critical and you can be guided by the DOF/distance markings on the lens. I'm not sure that there isn't some issue with exposure compensation with that screen on the OM1 variants also - can anyone else advise? Link to comment Share on other sites More sharing options...
frank_oddsocks Posted November 30, 2004 Share Posted November 30, 2004 Yes, the best general-purpose screen is the 1-3. Don't get the 2-3 or the Beatties, which will upset the metering on your OM-1. You could also get the 1-4, which lacks the central rangefinder devices, but as you are using reasonably fast lenses the 1-3 is fine. Good 1-3 screens are hard to find used. You should be able to sell the 1-12 easily. It is designed for greater than lifesize macro photography with the magnifying finder. Given all that, KEH ought to agree to swap screens with you as soon as they have a good 1-3 in stock. Link to comment Share on other sites More sharing options...
richard_oleson Posted November 30, 2004 Share Posted November 30, 2004 a 1-13 split/microprism, or a (i think it's 1-1) microprism spot screen, or an all-matte or matte-grid screen will also be okay (can't remember their numbers)... you have a non-focusing screen which can't be trusted for metering and has other issues as you've noticed. don't know if this is useful or not, but you can also use Pentax MX screens in the OM1: I have an MX matte-grid screen in one of mine. :)= Link to comment Share on other sites More sharing options...
skip_williams Posted November 30, 2004 Share Posted November 30, 2004 Take care of the 1-12 screen. Those will bring a good price to the right buyer. You should be able to buy a 1-1, 1-2, 1-13, or 1-14 screen pretty cheaply by asking around. I personally like the 1-1 and 1-2 with their simple center microprism. The all-matte 1-4 and grid 1-10 are also nice. See them all here: http://www.star.ucl.ac.uk/~rwesson/esif/om-sif/findergroup/focusingscreens.htm Skip Link to comment Share on other sites More sharing options...
rahul_deshpande1 Posted November 30, 2004 Author Share Posted November 30, 2004 How do I care for and store the 1-12 screen once I replace it with another? Anything to keep in mind, like special handling, wrapping etc? I'm assuming I would just put it into the case that the replacement screen comes in. Link to comment Share on other sites More sharing options...
richard_oleson Posted November 30, 2004 Share Posted November 30, 2004 the best way to store it is in its case- this way nothing touches the delicate surface of the screen. anything that touches it can scratch it, even 'protective' wrapping. Link to comment Share on other sites More sharing options...
ruben_bittermann Posted November 30, 2004 Share Posted November 30, 2004 If you do not have the original case and twizer (correct English?), you can gently wrap your screen with a clean and old piece of cotton T-shirt. By old I mean one that has been washed dozen or hundred times. BTW, this is perhaps the best material to clean lens surfaces. In case you do not have an old cotton T-shirt you can dare to use lens cleaning paper. Next, in order from good to less good, is any soft fabric dedicated to clean eye glasses. This solutions may not be microscopic safe, but good enough for any photographer whose desire to take pictures is greater than to admire his cameras. Cheers, Ruben Link to comment Share on other sites More sharing options...
skip_williams Posted November 30, 2004 Share Posted November 30, 2004 When you buy a new screen, use the plastic box that it comes in to store the 1-12. There's also a little brush and special tweezers that grab the screen's tab for insertion/removal. Or sell the 1-12 bare and keep the box. Skip Link to comment Share on other sites More sharing options...
timothy_mills1 Posted December 5, 2004 Share Posted December 5, 2004 Rahul, My guess is that you already have a Beattie screen in your OM-1. In my experience all the Beattie screens vignette with lenses wider than a 28mm in the OM bodies. The 28mm vignettes slightly, but not enough to be a problem. My 24mm with the Beattie behaved just as you describe. I finally took the Beattie screens out of my OMs for that very reason. If you look at the Beattie site they warn about this issue. If you use moderate wides or longer lenses the screens are great; very bright and snappy. Tim Link to comment Share on other sites More sharing options...
rahul_deshpande1 Posted December 7, 2004 Author Share Posted December 7, 2004 Timothy, How would I be able to tell if the screen I have is a Beattie? Asa matter of fact, I did notice that the cross hairs on my screen differ from the "1-12 cross hairs-clear field type" displayed on the website which Skip Williams mentioned. The cross hairs are made up of single lines, whereas the ones on the website are made up of double lines. On a separate note, I got my 1-13 screen today and fitted it into the OM-1N, it works beautifully. Rahul Link to comment Share on other sites More sharing options...
timothy_mills1 Posted December 11, 2004 Share Posted December 11, 2004 Rahul, Now that you have a OM screen you can compare it to the one that came in the camera. Factory OM screens have the screen designation printed on the tab of the screen. I took the standard one out of one of my OM-1s and it has a "13" printed on it. I am not certain how to verify a Beattie screen after the fact since none of mine have any markings on them. You could compare them side by side against a light source such as a window with an overcast sky and see if the "Beattie" seems brighter. Also when I look through my Beatties out of the camera they are bright and clear when I look straight through, but become darker if my eye moves even slightly off axis. I think this is the same effect as a wide angle lens causing light fall-off at the edges. The Beatties also look to have deeper cuts in the screen, but that may just be my imagination. Tim Link to comment Share on other sites More sharing options...
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