Need recommendations for 50mm or higher lens that is sharp across the lens

Discussion in 'Adapted Lenses' started by dsiglin, Jul 31, 2013.

  1. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    Here's the reason why I'm asking: I'm going to "scan" film with my Nex. I therefore need sharpness across the lens. Now, the El Nikkor line of enlarging lenses are sharp across the lens but I'm not sure how/if they can be used as a normal lens to take photos of film.

    So, I was wondering if you good folks might recommend a lens to me. Thanks in advance.
     
  2. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    Any legacy macro 50mm lens should be more than good enough. These lenses are generally very sharp across the frame at apertures around f/8. I have copied slides with my Panasonic GH2 and Panasonic 45/2.8 macro lens and that worked very well. I've tried it later with my NEX-6 and a Minolta MC Celtic macro 50mm because that's what I have and that worked fine too. I wouldn't go longer than 50mm on a NEX camera, with 50mm you already need quite some distance between lens and slide. I'd advise aperture between f/8 and f/11 so that you have enough depth of field to accommodate for curved slides.

    I have used a Nikon ES-1, a little known but very useable slide copying device which I read about here. I copied that setup with other lenses and cameras and I was happy with the results.
     
  3. ChangshaNotes

    ChangshaNotes Super Moderator

    Aug 15, 2012
    China
    Colin
    Thanks for that link Ad.
     
  4. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    Indeed, great link.

    Question, with the two spacers out in front of the lens, does that make it so the image being scanned is filling the camera sensor without anything being cropped? I'll be shooting mostly 6cmx4.5cm film so that's going to be a different setup than 35mm I suppose.
     
  5. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    Indeed. I happen to have a Nikon K-ring set which contains 3 rings with 52mm threads and different widths and I used them as spacers if necessary. Alternatively you can buy a stack of 52mm scrap filters, remove the glass and use the remaining rings as spacers, cheap and cheerful.

    For 6x4.5cm you may be better off with a shorter focal length, the Sony E 30/3.5 could do the job I think.
     
  6. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    I do have the Sigma MiniWide II with 1:4.5 "macro" and a minimum focusing distance of 9". Perhaps that would work for the 6x4.5?

    Now, I had a crazy idea for setup involving an ipad for a lightbox. It would look something like this:
    setup.

    The idea being I can easily adjust the distance from the camera to film and find the sweet spot.

    Alternate idea, I see macro addons like such which would be an easy and cheap way out but I guess might degrade image quality by adding more glass into the equation.
     
  7. WoodWorks

    WoodWorks Super Moderator

    Dec 12, 2012
    Ashland, OR, USA
    David
    Hm... might work. Though I think you probably will run into uneven lighting across the screen. I just fired up my iPad with one of the flashlight apps, and it has a definite "bright" and "dark" side.
     
  8. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    True, if it does I see tracing light boxes on ebay for fairly cheap, those would probably have a more even light distribution.
     
  9. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    Any retrofocus wide-angle lens like the Sigma MiniWide (28mm I guess) is bound to have uneven sharpness across the frame and distortion, mostly worsening at closer focussing distances. That's where macro lenses have the edge, they are specifically designed for low distortion and even sharpness. Same problem with close-up lenses (sometimes called macro "filters" but they're not really filters), image quality suffers. Legacy 50mm macro lenses are fairly cheap, to be honest I think your money is better spent on one of those.

    And I agree with Woodworks, even lighting can be a challenge. I'd bet on using opal glass (if that is a word, I mean glass or plastic that diffuses the light like the diffuser used in the Nikon ES-1) and lighting it from the back with a halogen light. My 50 Watt desktop lamp did a fine job. With the setup you presented it won't be a problem to handle larger distances between lens and slide so a 50mm macro lens should do the job without a problem. I had some 4x4cm slides my dad made a long time ago and I copied them by sticking them on a small slide lightbox which had a useable area of roughly 12x8cm. However, dismounting the slides and taping them to the lightbox is not a feasible process for more than a few slides :).
     
  10. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    addieleman, would you mind explaining what the difference is between the orange magnification ratios and the white? Is the orange what you get with the optional extension tube?
    663031133_o.

    It's looking like I need to buy two macro lenses, a 50mm for 35mm film and a 28-30mm for 6x4.5. Just when I was starting to get to reasonable amount of lenses.
     
  11. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    Exactly.

    Depends, maybe you can keep it to only a 50mm lens. For 35mm slides you need a magnification ratio of 0.65 (1:1.54) and for 6x4.5cm 0.35 (1:3). So for 35mm slides you'll need the extension tube. For 6x4.5cm you'll need a distance between lens and slide of approximately 194mm; if you can work with that, a 50mm lens will do. A 30mm lens will give you a distance of 117mm, still fairly large. It all depends on your setup. I don't know if there exists ready-made stuff for copying 6x4.5cm slides; if not, you'll have to make a contraption yourself.

    BTW, I think 50 lenses is a reasonable amount, so I don't see how adding 1 or 2 lenses would make a significant difference. But that may just be me... :)
     
  12. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    50? Wow. Can we start addielman loans to talknex thing? I have 4 lenses for my Nex and that still feels like a lot.

    Ok so thanks for doing the math, looks like that would be about 7.6 inches for the 50mm and 4.6 inches for the 30mm. That's not horribly far away and I can even make a tunnel to shoot into.

    Question though, the minimum focusing distance for the MD 50mm 3.5 macro is 9.6 inches. So it looks like the distance I would need to be for 6x4.5 negatives to get 1:3 would be 7.6 inches. That's not possible with the 50mm 3.5 or am I missing something?
     
  13. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    No can do, need them all to play with myself. BTW, I said 50 is a reasonable amount, I never said I only had 50 myself...

    The scale on the lens indicates the distance between the sensor plane marker on the camera and the subject.
    i-BHhD3sp-L.
    I was talking about the distance between the front glass of the lens and the subject, which can only be calculated approximately, say with a tolerance of 10mm for this type of lenses and that is accurate enough for what we're doing here.
     
  14. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    Setup is almost complete, I am waiting on LED bulb for backlight and need to design/build a permanent attachment for negative holder to slide through. In the mean time I did a quick n' dirty where I taped an old negative from my holga to semi-opaque plexiglass and put a 60w light behind. Enlarging lens was set at f16. I just propped the plexiglass against the light source and shot away. Not as refined as the final system will be but the results I got are promising. I was able to resolve to the grain. I don't remember what film I used, and the image itself is very not sharp, in typical holga fashion. Here's the "scan". Obviously downsampled so it can be uploaded onto here.

    E~6779717fae42479c93a4fd2a34f9e35a.
     
  15. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    That looks workable. If you're going to do color slides and you're not happy with color rendition, try a halogen or a normal tungsten light to see if it makes a difference. White LEDs have a different spectrum, it seems that cyan can be under-represented.
     
  16. dsiglin

    dsiglin TalkEmount Veteran

    230
    Apr 23, 2013
    Greenville, SC
    Definitely a good idea to try various lighting sources and pick one that works the best. I want to eliminate all variables (lighting, distance, etc, etc) so I can make a streamlined workflow in photoshop or lightroom. I'm hoping I can make a white balance for each of the color film types I shoot. I shot that in raw which gives me great latitude to bring out details in the negative. Once I get the final iteration of the "rig" and am happy with the results I'll post a how-to. I just shot some B&W with my Mamiya 645 at a friends wedding so those will be a better judge of resolving power than a holga negative. :) Still, being able to see the grain on the full sized "scan" is heartening.