adrian_theze1 Posted February 10, 2015 Share Posted February 10, 2015 <p>I bought a Mamiya 645 pro and am using a 120 film back. I'm struggling with focus issues and I'm trying to track down what can be causing this from the obvious, my 50 year old eyes, to the less obvious. I've tried focusing with glasses and without and am still getting soft images.<br> I've just put another test film through the camera, again all images are soft. One thing I have noticed is that the corners of the negatives are not at right-angles as I'd expect but rather, from the longest edge they curve inwards to the shortest edge. This is suggesting to me that the film holder is not holding the film flat. It's a similar effect to projecting onto a less than flat screen with a projector. I'm sure if this is the case, it would certainly add to sharpness issues. Should I purchase another film back as this one isn't doing the job it should or is it something I'm doing wrong. I'm very careful when loading film to keep both spools tight.<br> Thank you.</p> Link to comment Share on other sites More sharing options...
stephen t Posted February 10, 2015 Share Posted February 10, 2015 <p>Do you have a copy of the manual and follow it to the letter regarding loading the film? I have several 120 bodies and loading the film backs does not always seem intuitive to me. I've considered carrying a copy of the film loading procedures in the respective camera bags just to be sure I have a reference available. <br> If you are sure the film is loaded correctly, the issue could be with the focusing screen or the pressure plate. I'll be watching this thread to see what other more knowledgeable folks have to offer.</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Thank you Stephen for for your response. I'm certain I'm loading the film corectly. The following image illustrates my problem. The curling at the corners can be seen quite clearly.</p> <p><img src="https://space1eleven.files.wordpress.com/2015/02/img119.jpg" alt="" width="782" height="1718" /></p> Link to comment Share on other sites More sharing options...
dave_thomas8 Posted February 10, 2015 Share Posted February 10, 2015 <p>If you're e-speaking of the little point at each corner, that is likely just the mask/film gate shape. Such artifacts are pretty common with many medium format cameras.</p> Link to comment Share on other sites More sharing options...
stephen t Posted February 10, 2015 Share Posted February 10, 2015 <p>ditto Dave's response - I get those as well.</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Thank you Dave. I can check that one off the list then. Much appreciated! </p> Link to comment Share on other sites More sharing options...
John Seaman Posted February 10, 2015 Share Posted February 10, 2015 <p>It may be worth reading this:</p> <p>http://www.photo.net/medium-format-photography-forum/00aUH5</p> <p>Even if the focus screen is upside down or displaced, or if the mirror isn't in the correct position you should be getting sharp results for the type of shot you posted, just be setting the lens to infinity.</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Thank you John, I took some shots with the focus set at infinity using my 35mm 3.5 Sekor C lens. At the infinity mark the images were very soft, as were those I considered sharp without my glasses. I couldn't really see terribly well at all through the viewfinder with my glasses to know if the image was sharp or not. <br> I experimented focusing at different points around the infinity mark and did get one image I guess I would consider acceptably sharp but it's very soft on the left side in the middle distance compared to the right and it's not perfect by any means. This rather hit and miss approach to getting a sharp image of course isn't sustainable.<br> <img src="https://space1eleven.files.wordpress.com/2015/02/scan-150209-00052.jpg" alt="" width="950" height="780" /><br /> <br> In some ways I feel I'm at a disadvantage in that I really don't know what to expect in terms of rendition of detail and sharpness but, coming to medium format from shooting with a D800e I expected it to be as good and better and certainly better than this. This 950px jpeg looks OK of course, it's the full size image where the softness really shows. The disadvantage of scanning a negative and then viewing in Photoshop is we can pixel peep and maybe I am expecting too much.<br> This is my best image taken with my 80mm and cropped but it's not knife edge sharp..<br> <img src="https://space1eleven.files.wordpress.com/2015/02/scan-150208-0006a.jpg" alt="" /><br> Perhaps this is all does come down to my aging eyesight and a lot more practise using manual focusing required. I've ordered a +1 diopter being the closest to that which I use with my D800e (I think). I asked Nikon for the exact scale and range used on the D800e but that was restricted information apparently so I'm guessing a +1 will come closest. Maybe this will improve things. The focus screen fitted does not have a rangefinder spot so have ordered one with and maybe this will help further.<br> Thank you once again. I did look at the link you mentioned earlier today.</p> Link to comment Share on other sites More sharing options...
stephen t Posted February 10, 2015 Share Posted February 10, 2015 <p>What f-stop are you using? I wonder if you are getting diffractive interference with a very small aperture??<br> What film and what developer are you using? They will affect perceived as well as actual sharpness.<br> I think the flowers look just fine. Well, better than just fine, in my opinion! Window light?</p> Link to comment Share on other sites More sharing options...
John Seaman Posted February 10, 2015 Share Posted February 10, 2015 <p>To be honest these images don't look unsharp on the screen, but its hard to judge by 700 pixel images.</p> <p>Could it be happening during scanning?</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Thanks again Stephen. I was using f/11 for the landscape so deffraction shouldn't be a problem. <br> Both these pictures were shot using Pan f Plus 50, developed in Ilfosol 3, 1+14 for 6 minutes at 18°C. Thank you on the daffodils. I was pleased with the tonal range and texture. I used two lights with daylight bulbs, reflective umbrellas and a bit of white card as a backdrop.</p> Link to comment Share on other sites More sharing options...
stephen t Posted February 10, 2015 Share Posted February 10, 2015 <p>Adrian, everything you are doing sounds just fine to me. As John said, maybe during the scan? Have you looked at the negatives on a light table using a loupe? </p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Thanks John. I'm using an Epson V600 and putting the negatives in the proper carrier. They're sitting nice and flat so I'm guessing scanning isn't the problem. I shall see if the diopter improves things. I'm certainly enjoying using the Mamiya and doing the processing. It's been quite a revelation after digital. <br> The diopter I've ordered will be here in a few days. I'll take another test roll and see if there is any improvement and take it from there.</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 10, 2015 Author Share Posted February 10, 2015 <p>Checking the negatives seems like a good idea Stephen. I'll have to build a light table, I'm sure it can be done quite simply with a sheet of acrylic and some two by two, and I will check the negatives. That will at least tell me if there is a problem with the scanner.</p> Link to comment Share on other sites More sharing options...
stephen t Posted February 10, 2015 Share Posted February 10, 2015 <p>Check around for used xray viewers - since docs are switching to digital imaging, they are very reasonably priced now. If you are viewing B&W as I do, color balance won't matter. I use a Mamiya RB67 chimney finder or my Toyo field camera loupe to check negatives, along with an xray viewer mounted on the wall and they work great.<br> Keep in mind also, that film "looks" different from digital - that's part of it's charm for me. Kudos again on the daffodils - very nice.</p> Link to comment Share on other sites More sharing options...
martin_dake Posted February 10, 2015 Share Posted February 10, 2015 If you have a tablet like an iPad you can find a light table app for it and use it to view your negs. Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 11, 2015 Author Share Posted February 11, 2015 <p>Thank you Martin, I have a tablet, I'll check it out.</p> Link to comment Share on other sites More sharing options...
lubos_soltes Posted February 11, 2015 Share Posted February 11, 2015 <p>what DPI are you scanning at ? V600 has a practical limit of around 1300dpi for medium format film.</p> <p>1. check the negative with a good loupe<br> 2. send one or two frames to somebody with a "proper" scanner (drum scan, Imacon, Nikon 8/9000)</p> <p>I have the previous model (V500) and I scan up to 3200dpi but only for experiments. 2400DPI is about the absolute limit that shows any gains (however small). And the resulting picture is ALWAYS SOFT on pixel level. You cannot get D800 level acuity from a flatbed film scan. never. simply not possible.</p> Link to comment Share on other sites More sharing options...
ondebanks Posted February 11, 2015 Share Posted February 11, 2015 <p>Adrian,<br> <br />My comments are:</p> <p>1) The outwardly curved image corners are absolutely normal with the M645 range. This is not a flaw.</p> <p>2) It sounds like your 35mm C lens has a misalignment problem. You say "At the infinity mark the images were very soft" and "it's very soft on the left side in the middle distance compared to the right". Both of these statements started alarm bells ringing. My 35mm N (same optical formula bar the coatings) is extremely sharp centrally at infinity, even wide open, and even on smaller-pixel digital bodies. And a classic sign of a misaligned lens is that it is softer on one side of the image than on the other. Furthermore, the 35mm lens (a) is an ultra-wideangle and (b) incorporates a floating element. Both characteristics make it more prone to image degradation from misalignment, usually after it's taken a fall.<br> I think it's better to test for possible camera issues by using your more robust 80mm lens.</p> <p>3) The daffodils photo is lovely, but it's not the best subject for a focus test - too 3 dimensional and irregular, and using the 80mm lens in its close focus range is not where it is optimised (I'm assuming you have an 80/2.8 or 80/1.9 and not the 80/4 macro).<br> I'd run a series of 80mm exposures at infinity, varying the aperture from wide open to its smallest stop.</p> <p>4) I'd agree with others that a flatbed scan won't give you more than about 2000 dpi of real resolution. With a 645 frame, that's around 15 Mpix equivalent, some distance behind a 36MP D800E. But slow film, good technique and a "proper" scan (as per Lubos' post) can produce over 40MP.</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 11, 2015 Author Share Posted February 11, 2015 <p>Thank you Ray and thank you Lubos. I didn't take up medium format film photography to compete with my D800, there's a lot more to it than that obviously, but as I mentioned in my original post, I expected better than I was getting and I now have a lot of clues as to why that might be. I will be returning the 35mm as I agree, sharper on the left than on the right is not a good sign at all.<br> I will do as you suggest and run a series of tests with the 80mm lens.<br> I don't have the money for a Nikon 9000 scanner, even second hand, so I will make do with my scans as they are. I'm sure once I've got my focus issues resolved they will be much improved anyway and good enough for the Web.<br> I will hopefully be printing from my negatives in the not too distant future. Another very steep learning curve but one I'm looking forward to but I need to make sure I can get a good sharp negative first.<br> Thanks everybody once again for your very helpful advice.</p> Link to comment Share on other sites More sharing options...
lubos_soltes Posted February 12, 2015 Share Posted February 12, 2015 <p>Adrian, the V600 is a good scanner for proofing and small sizes. I have printed a satisfactory 50x60cm BW from a V500 scan (I am using a 6x7 camera, so I am getting a bit more data from the scan), the main limit was my sloppy shooting technique. By satisfactory I mean it was not a complete disaster :-)<br> <br />However if you want to achieve top results (or large sizes) there's no going around a drum scan. But this is usually needed only for a few frames a year (depends on your needs of course) and using a mail-in scanning service is the usual practice there.<br> <br />Good luck with the testing and future gear so you don't have to face lens issues in the future :-)</p> Link to comment Share on other sites More sharing options...
xenophon_costeas Posted February 13, 2015 Share Posted February 13, 2015 <p>Ah, sharpness! We can never have enough!</p> <p>Seriously, though. Before you blame eyesight trouble or the Sekor, I believe you shound run tests with mirror lockup and/or a cable release [at 1/125, 1/250 and 1/500 shutter speeds]. </p> <p>Mirror and camera shake are, to my mind, the most likely culprits when it comes to that (slight, but depressing) sense of softness.</p> <p>If you want, check out my sharpness troubles at:</p> <p>https://lycabettus.wordpress.com/2012/07/09/shooting-the-mamiya-rz67-handheld-how-much-sharpness-one-sacrifices-over-a-tripod-and-mirror-lock-up/<br> <br> With greetings from Athens,<br> <br> Xen</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 13, 2015 Author Share Posted February 13, 2015 <p>Thank you again Lubos for your invaluable advice. It's all part of the journey.. :-)</p> Link to comment Share on other sites More sharing options...
adrian_theze1 Posted February 13, 2015 Author Share Posted February 13, 2015 <p>Thank you very much Xen! I've read your post. Very interesting. I always use a tripod, I'm going to have to get in the habit of mirror up as well.</p> Link to comment Share on other sites More sharing options...
william_frucht Posted February 14, 2015 Share Posted February 14, 2015 <p>Adrian, bending of film in the scanner is much more of a problem with MF than with 35mm, and if some areas of your images are sharp but others are soft, this could be what's happening. Even a barely detectable warping will throw parts of the image out of focus. When I had my late, lamented Nikon 9000, I had to use a glass negative holder. Let me suggest a simple test that will tell you if the problem is in the camera or in the scans. When you magnify your images in Photoshop (or Lightroom, Aperture or whatever), look for the grain structure. In the sharp areas, of course, both the image and the grain will be sharp. In the soft areas, if the grain is still sharp then the problem is in the camera. If the grain is soft (or not visible), the problem is in the scans: the negative is not being held flat enough. I'm currently using a Plustek Opticscan 120, which has other issues, but the negative holder is quite good.</p> Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now