joe_hoyle Posted February 6, 2007 Share Posted February 6, 2007 hey guys ive got a realy big problem. i have been shooting on a mamiya rb67 using ilford delta 100. i am taking photog of trees and wooded areas for my current college project where i am studying ansel adams. it is the texture of the bark i am most interested in. my last 3 films have all been very slighty out of focus. you cannot notice this on the contact sheets but it looks terrible even when printed 10*8. i have been using an aperture of either f32 or f16 and shutter speeds have been between 15th and 1 second. now i am sure it isnt the camera or my eye, i even had a freind come with me to confirm that the shots were focused! cheers! please please please help! Link to comment Share on other sites More sharing options...
lauren_macintosh Posted February 6, 2007 Share Posted February 6, 2007 Suggest you go to this web site and read it thru and thru : [tim@FocusTestChart.com] it also has a couple of targets you can use to check your lens with: Link to comment Share on other sites More sharing options...
SCL Posted February 6, 2007 Share Posted February 6, 2007 Tripod...tripod....tripod. Also better to choose the sweet spot of the lens instead of f32 or 16...for most Nikon lenses it is around f8. Link to comment Share on other sites More sharing options...
michaelging Posted February 6, 2007 Share Posted February 6, 2007 I too suspect camera movement, can you post a example , its easy to tell. Link to comment Share on other sites More sharing options...
frank uhlig Posted February 6, 2007 Share Posted February 6, 2007 It might not even be "out of focus", but just diffraction at f/32. Try to get a hold of a good tripod and expose no narrower than f/11 and see. I think your poblem will be miraculously cured then! Link to comment Share on other sites More sharing options...
alex_lofquist Posted February 6, 2007 Share Posted February 6, 2007 Diffraction should not be a problem for a medium format camera at f/32, though I would consider f/22 to be a better choice of aperture. Do you have mirror lock-up capability? If the image is sharp to your eye but not on the film, then you have to determine if there is a problem involving the reflex mirror or the focussing screen. Try doing a series of photos with the lens defocussed small amounts from the best visual image. Keep a record and see if you can establish a correlation of sharpness vs offset. Some older lenses with serious spherical aberration will show a "focus shift" as the lenses are stopped down from wide open. To check this out, compare images made wide open (or one stop down) to those made at f/16 or f/22. Just curious, but what lenses are you using? Link to comment Share on other sites More sharing options...
edsel_adams Posted February 6, 2007 Share Posted February 6, 2007 A likely culprit could be your focusing screen. I would make certain it is seated correctly Have you tried using a tape measure to check distances? This should settle any and all arguments. Link to comment Share on other sites More sharing options...
joe_hoyle Posted February 6, 2007 Author Share Posted February 6, 2007 i will post up a photo later when i am home and see what you think. it is only a bit out, but it is realy frustrating. i am unsure of the lens as the camera is from college but i have used it alot in the past without any trouble at all. i am using a realy hefty manfrotto tripod and i am positive it isn't camera shake. i have only two weeks left, i have shot 10 rolls of film with only one final print to show for my efforts, the last 4 films i have all had this trouble. coincedently they have just started to look good as i have been experimenting with n+1 development. ok picture up asap. thanks for the help, joe. Link to comment Share on other sites More sharing options...
madredhen Posted February 6, 2007 Share Posted February 6, 2007 Have you had this trouble from the start, or did you notice a big difference at some point like the camera might have been dropped or jarred and the film holder is maybe no longer perfectly aligned? Check that the film back is not loose, if the film is not on the correct plane it will not be in focus. If the bellows are tilted only a fraction of the photo may be in sharp focus, at f16 or 32 everything else may be just slightly out, so check for consistency of focus across the whole image and if there is one segment in sharp focus it could be the bellows. Probably a better place to ask this question is the medium format forum of photo.net Link to comment Share on other sites More sharing options...
joe_hoyle Posted February 6, 2007 Author Share Posted February 6, 2007 i have treid two different film backs for the camera. ok here are some photo's, the first i printed up yesterday. heres a few from the cntact sheet, the pic of my little bro was to test a wider aperture (5.6) and although i havnt printed it bigger it looks good to me. please try and help! joe Link to comment Share on other sites More sharing options...
bill_bayless Posted February 6, 2007 Share Posted February 6, 2007 I had this problem a number of years ago with the RB67 and discovered the focusing screen was in upside down. I hope this helps. Link to comment Share on other sites More sharing options...
joe_hoyle Posted February 6, 2007 Author Share Posted February 6, 2007 the other ones didnt work. here is one shot of my little brother on f5.6 excuse all the marks on it, it is from the glass i used when making the contact sheet. Link to comment Share on other sites More sharing options...
kelton Posted February 6, 2007 Share Posted February 6, 2007 Joe, I too use RB67 for nature photos...also with some trouble. Here is what I have figured out... 1. My RB 67 lenses ( 90mm and 127mm) suck at f22 & f32...2. Hand-Holding this camera, use 1/125 or 1/250 shutter speed until you get used to it. I will sometimes hand-hold at 1/60 if wind is not blowing. 3. use a tripod and take your time. 4. Reaching for infinite focus often gives unpleasing results (at least for me.) I get much better results in the studio, but, then again, this is a great studio workhorse. Link to comment Share on other sites More sharing options...
joe_hoyle Posted February 7, 2007 Author Share Posted February 7, 2007 ok well i am getting the camera today and i am going back to try the same shots on say f5.6 and f8 and see what happens, i hope this works. if it doesnt it look like i am going to have to shoot on my lubetel :s i'll post up with the outcome on thursday after i have deveopled the film. Link to comment Share on other sites More sharing options...
Two23 Posted February 7, 2007 Share Posted February 7, 2007 1.For shutter speeds less than 1/30 you should be using mirror lock up. This is VERY important at the speeds you used on that camera especially. 2. You are aware that there is a minimum focus distance for most lenses? That is, a lens won't focus if it's too close to the subject? 3. Try f16, remembering that half the subject goes in front of your point of focus and half goes behind it. 4. Is the focus screen firmly seated? Kent in SD Link to comment Share on other sites More sharing options...
dan_fromm2 Posted February 7, 2007 Share Posted February 7, 2007 Kent, when the lens is focused to its hyperfocal distance, everything from half the hyperfocal distance to infinity is in focus. Isn't "half the hyperfocal distance to the subject" somewhat less than half "subject to infinity?" Link to comment Share on other sites More sharing options...
joe_hoyle Posted February 7, 2007 Author Share Posted February 7, 2007 i have just done another film on the mamiya and a film on the lubetel, measured the focal length on the lubetel so i can compare. if it is a fault in the camera i think i am going to ask for an extension on my project, ive still got to print up the finals! Link to comment Share on other sites More sharing options...
J.W. Wall Posted February 11, 2007 Share Posted February 11, 2007 Why not ask your instructor these questions, with photos in hand? Link to comment Share on other sites More sharing options...
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