1. Reminder: Please use our affiliate links for holiday shopping!

Practical difference between 1.4 and 1.7/1.8 ?

Discussion in 'Adapted Lenses' started by Amamba, Dec 19, 2013.

  1. Amamba

    Amamba TalkEmount All-Pro

    Apr 13, 2013
    SE MI
    Curious as to what the practical difference would be between 50/1.7(8) and 50/1.4.

    That's only about 1/3rd of a stop, not enough to make a noticeable difference in shutter speeds, and the DOF calculator for an object 5' away (or 1.5m, which would be the closest portrait distance) shows the DOF for f1.4 at .05m and for f1.7 at .06m - the difference of just .01m / 10mm or less than 1/2".

    So, unless you're after a particular lens for it's particular character, what makes 1.4 more desirable than 1.7/1.8 ? I would think that the impact won't be as noticeable as going from 2.8 to 1.8, or from 1.8 to 1.2.

    Now a disclaimer - I don't own a 1.4 lens, the only one I ever came across was MD 50/1.4 and by most user reviews it's not as sharp as 50/1.7 so I passed.
     
    • Like Like x 1
  2. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Hmm... what I can contribute based on my personal experience is that the MD 50mm f/1.7 WAS my favourite portrait lens until I got an MD 50mm f/1.4.

    Pretty much the same optical quality/color rendering IMHO but that extra speed was an added bonus for me that I shoot frequently indoor/low light portraits. Sometimes I have to shoot wide open (that both lenses handle pretty good in my opinion) but with the 1.4 I was able to skip flash (hate it), keep ISO lower perhaps and/or maintain a decent shutter speed - important since my portraits are of my kid(s) running around ;)

    Plus, its a faster lens - everybody want fast, lol :D

    edit: now I want an 1/1.2 :p
     
    • Like Like x 1
  3. Bugleone

    Bugleone TalkEmount Veteran

    210
    Aug 21, 2011
    The main "practical differences" are that 1.4 is twice the size, weight and usually price of the f2 lenses......1.8 or 1.7 in real terms these are f2 lenses.

    Depth of field is negligible, but strangely the real impact of the max aperture is found further up...ie, most lenses reach optimum image quality when stopped down 2 stops,..so, 1.4 lenses are around their best at 2.8 and the f2 lenses at f4, and there is considerably MORE depth of field between f4 and f2.8 as depth of field lenghthens as aperture reduces.

    The large aperture 50's were important in the film era but are not now apart from the 'posing value' of being a current fad. The grain difference between 200 and 400 iso/ASA film was 'huge and horrible' so the fast 50's offered a real solution in many situations. With the superb quality of 1600 iso in digital this need is now obviated.
     
  4. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    For me it depends very much on the optical qualities of the different 1.4/1.7/1.8/2.0 options. In the Minolta range the 1.4 lenses are generally better than the 1.7 lenses, but in the Nikon range I preferred the f/2 50mm because it was better at f/5.6 than the e.g. 50/1.4 AIS.

    I've never understood this point of view. With my A7 I'm comfortable with ISO 6400 and I still really like to have a fast lens because it gives you extra options in reducing noise or upping the shutter speed. It's just great fun to be able to make pictures under circumstances that wouldn't allow that with a slower lens and/or noisier camera. While I grant you that ISO 1600 is indeed excellent these days, on both my NEX-6 and A7, but why limit yourself? Just a few weeks ago I took pictures at my daughter's master's ceremony and I was glad to have the option to use a 50/1.4 and let the auto ISO go up to ISO 6400 if so needed. It made for some very nice pictures in a dimly lit restaurant.
     
    • Like Like x 1
  5. Amamba

    Amamba TalkEmount All-Pro

    Apr 13, 2013
    SE MI
    A lot of interesting info, thanks !

    So looks like I should've got that Minolta 50/1.4... I read some review stating 50/1.7 was about as sharp at 2.8 and sharper at 4.

    There's a Canon FD 50/1.4 on local CL, but the reviews are kind of mixed, plus I don't want to open the Pandora box by getting another adapter type

    Sent from my Nexus 7 using Tapatalk
     
  6. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Not the case with all lenses, Minolta MD for example, more or less same size and weight between the 1.7 and 1.4...
     
    • Like Like x 2
  7. porchard

    porchard TalkEmount Rookie

    14
    May 8, 2013
    At risk of sounding pedantic (but, in fact, just hoping to help;)), the difference betweenf/1.4 and f/1.7 is actually 0.56 of a stop, while the difference between f/1.4 and f/1.8 is 0.73 of a stop, so... these values just might make a noticeable difference in shutter speed.
     
    • Like Like x 2
  8. Deadbear77

    Deadbear77 TalkEmount Hall of Famer

    Sep 14, 2012
    Northeast Ohio
    Kevin
    I started out on minolta legacy glass, I like having the 1.4 minolta, had stops at 2 and 2.8 where as the 1.7 goes right to 2.8.

    I like my canon lenses also for the stops,

    My 50 1.4

    1.4, 1.8, 2, 2.2,2.8, ect

    My 55 1.2

    1.2, 1.4, 2, 2.2,2.8 ect
     
    • Like Like x 2
  9. dbmiller

    dbmiller TalkEmount Top Veteran

    777
    Mar 2, 2012
    New England
    Okay... If we're going to get pedantic... :)

    F-stops are traditionally rounded. And are often in 1/2, 1/3, or 1/6 stop increments.

    1.8 is more than likely 1.782 rounded up to 1.8 and is 2/3 stop above 1.4 (Which is actually 1.414)

    1.7 is more than likely 1.682 rounded up to 1.7 and is 1/2 stop above 1.4
     
  10. porchard

    porchard TalkEmount Rookie

    14
    May 8, 2013
    Agreed - but I wasn't trying to be pedantic... in fact, I was making an effort not to appear pedantic!;):biggrin:
     
  11. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    I agree, the real reason to get the 50mm MD Rokkor F1.4 is to be able to have it sharp, and still really fast at F2. I only shoot wide open with it when it is super dark.
     
  12. Jefenator

    Jefenator TalkEmount Top Veteran

    876
    Nov 23, 2012
    Oregon, USA
    Jeff
    Practical difference between 1.4 and 1.7/1.8 ?

    About $200 and 6 ounces. :biggrin:

    Kidding aside, in my limited travels it seems like the 1.7/1.8 lenses are often the basic "kit" lens from back in the day while the 1.4 as an expensive upgrade gets more loving attention from the manufacturer. My tests seem to jibe with that hunch - a general trend of better all-round performance with the 1.4s.

    Of course there will be exceptions. I recently got a Leica Summicron 50/2 which is pretty darn good wide open. OTOH my old Minolta MC-Rokkor 50/1.4 (which I paid literally 1/25x as much for) is a tiny bit better than the Leica at f/2. (It is also a lot bulkier…)
     
  13. Gandalf

    Gandalf TalkEmount Regular

    59
    Sep 5, 2013
    :dash2:
    And the correct form is "f/stop," never "f-stop" because we are denoting the focal length, f, divided by the aperture or stop.

    If we're going to get pedantic... :D
     
  14. dbmiller

    dbmiller TalkEmount Top Veteran

    777
    Mar 2, 2012
    New England
    Touché