50 f/1.4 Soft Focus

[carl_s]

<p>Good morning all,<br>

I recently replaced my 50mm 1.8D with Nikon's 50mm 1.4G (albeit a refurb). I was very excited to have Nikon's top offering in the 50mm prime series. However, I have to say I'm a bit disappointed with the sharpness. It seems like I was able to get better performance out of the D lens. It's difficult to make an apples to apples comparison as I already gave my D lens away. So - I'm hoping someone here will take a look at a couple sample images and let me know if these are fair representations of what I might expect from this lens. Or... might I have a bad copy? I realize that there's an awful lot of technique involved, but since I am feeling that my D lens was sharper, I'm thinking that may not be the issue here. <br>

Below are links for two images, one at f/2.8 1/100 and the other at f/2.2 1/100. I have used single point AF to focus on one of the child's eyes in each photo. The link is for the raw image so that you can see exactly what was captured without any of my LR edits and/or sharpening.<br>

Thanks for any thoughts all. <br>

Best regards,<br>

Carl</p>

<p>http://www.dropbox.com/s/4j0raln6xalwvct/_CRS2951.NEF?dl=0<br>

http://www.dropbox.com/s/ue2xblif6xw6txp/_CRS2961.NEF?dl=0</p>

[ShunCheung]

<p>Carl, the images you attached are 24M RAW files. Could you post some smaller JPEGs. You can just crop the critical parts for us to view.</p>

<p>And a better way to test sharpness is to put your camera on a tripod and use live view to manual focus. Depth of field at f2.2 is narrow. Any slight focusing error will throw off your results. Personally, I don't pay much attention to sharpness at f1.4 and f2. Most of your image will probably be out of focus anyway.</p>

[carl_s]

<p>Shun,<br /> <br />Certainly... Here is a link to a JPEG crop with no clarity, sharpening, or noise reduction applied (<2 MB each). I understand using the tripod for best results. Also understand the shallow depth of field at such a large aperture. However, I was used to the eyelashes being wonderfully sharp with my D lens.<br>

<br /> I was really just looking for the general "oh that is bad" or "eh, that's about right" response from those who are more experienced than myself. I'm trying to decide if I should contact Nikon and ask for a different copy of the lens.<br>

<br /> Thanks for your thoughts.<br>

<br /> https://www.dropbox.com/s/a0rw3i34vopx26u/_CRS2951_Crop.JPG?dl=0<br>

https://www.dropbox.com/s/mv3nhbgdw7e5kxw/_CRS2961_Crop.JPG?dl=0</p>

[chip_chipowski]

<p>In the shot with the bib, the blue bib seems to be very sharp and in focus. In the guitar shot, it looks to me like there may be some motion blurring going on. In any event, those both look like challenging shots in terms of nailing focus with shallow DOF. I agree with Shun's recommendation to put the camera on a tripod and do comparison shots using live view manual focus.</p>

[SCL]

<p>It looks to me like the point of focus is actually further back than the eyes. Did you try putting your camera on a tripod and setup a test chart and use compensation for the point of focus? I've had to do that with a couple of lenses to nail it within one mm. Nice shot BTW.</p>

[kari_oinonen]

<p>Check your lens first with the live view af using a tripod and a controlled setting.<br>

The second image shows possibly, that your camera plus lens are doing a bit of front focusing. This is not a problem if our current camera has the af-fine tune possibility. You might want to check how the af-fine tune can improve the focus/sharpness.</p>

[thomas_k.]

<p>For me 1/100 of a sec is camera shake danger zone, I like to keep my shutter speed at 1/125 or 1/160 for better handheld results.</p>

[Ed_Ingold]

<p>I tested a Nikon 50/1.4 AIS extensively using a Sony A7ii. The performance was pretty good, even compared to a Leica Summicron 50/2. If anything, I should think a newer model of the 50/1.4 would be better yet. Focus was always an issue on a Nkon, considering the shallow DOF. The A7ii allows for very accurate focusing with negligible camera shake (electronic shutter), letting the lens speak for itself.</p>

<p><img src="http://d6d2h4gfvy8t8.cloudfront.net/18045163-md.jpg" alt="" width="680" height="306" /></p>

<p>The magnification in this example is fairly high, as sampled from the overview below.</p>

<p><img src="http://d6d2h4gfvy8t8.cloudfront.net/18045161-lg.jpg" alt="" width="1500" height="1000" /></p>

[carl_s]

<p>Hmm.. All interesting comments. Thanks. Here is a tripod shot, f/4.0 1/200s and is more what I was looking for. However, I've increased the depth of field dramatically and doubled the shutter speed to get these results. <br>

https://www.dropbox.com/s/hgjqj6cm65jdmpi/_CRS2967_Crop.JPG?dl=0<br>

Perhaps I should be asking more technique related questions than equipment related ones. However, the idea of testing performance using a chart is intriguing to me. Does anyone have any resources that they might suggest for a first timer when it comes to using autofocus charts?<br>

<br /> As a sidenote, I had set the camera at minimum shutter of 1/100 using the twice the focal length rule. Maybe when trying to shoot candids of kids I need to rethink thatdecision and set something a little faster.</p>

[Gup]

<p>Carl, unless I've missed it, you haven't told us what body you are using or if this lens is the AF-S or AF model.<br>

I'm guessing the AF-S as you stated, "Nikon's top offering in the 50mm prime series." I happen to have the AF version of the 50mm G lens. I acquired it with the purchase of a used D700 body a few years back. I didn't use the lens for a long time, thinking it substandard to others I have. When I did finally use it on a D800E last year I was amazed at its sharpness. Really surprised. Subsequently I use it regularly now as a carry-around lens because of its size and weight advantage over my others. I also was able to 'fine-tune' it with my D800E, something I'm not sure your body is capable of. I don't think I've ever used a tripod or Live view with this lens mounted. I'd also use a higher f/stop if sharpness was a primary concern. Of course, it would be a trade-off if softer background rendering is your goal.<br /></p>

[SCL]

<p>Carl - check out this link explaining the process in very simple terms (http://www.nadeenflynn.com/calibrating-your-lenses-tutorial/). I've used Tim's chart for years and it works quite well. You should take notes as you're making adjustments...and view the results on your pc screen lightly sharpened. It is quite intuitive. Make sure your angles in the test are accurate to get good results.</p>

<p>When shooting candids of kids, use the fastest shutter speed you can, their micro movements, as well as your own pulse, introduce movement which really isn't minimized until around 1/500 sec. Either bump ISO or use a bounce flash.</p>

[chip_chipowski]

<p>I think Stephen's advice about 1/500 is a good if you want to avoid subject movement. I will just chime in to say that my indoor photos of my 3 year old are usually taken with auto-ISO set to a minimum shutter speed of 1/60. Obviously, at 1/60 subject movement is an issue so it is all about timing. Some of those low light shots have displeasing signs of motion, and those are discarded. Some shots have no motion on the critical focus point (eyes for example). Other shots have pleasing motion (to me). I attached one such example. I don't have the EXIF data for this shot but I think it was 1/60. So my advice is to either increase shutter speed, or increase the number of shots you take and come to terms with a low keeper rate :)</p><div></div>

[rodeo_joe1]

<p>Well, I can't see any of those dropbox images, and I suspect I'm not the only one. I just get the message that IE can't display the webpage.<br>

Why not just attach a few 100% crops to a post? Instead of making every potential viewer jump through hoops to see them.</p>

[carl_s]

<p>Gup - You didn't miss anything. I left out some important detail. The lens is the AF-S model on a D750. <br /> Stephen - Thanks for the link. I intend to look into this as soon as my kids will let me focus (pun intended) on something for more than 2 minutes. <br /> Chip - I guess this is part of everyone's dilemma. For natural light shots, I have been using 1/100 as a minimum and managing depth of field in A mode, selecting the aperture as appropriate for the shot. The D750 gives me huge flexibility (compared to my previous Nikon) when it comes to ISO selection. Still though, there's a big advantage to getting good results at large apertures and lower ISO's when it comes to noise.<br /> In the end, the whole reason for starting this thread was that I was absolutely enamored with the performance from my 1.8D lens. I bought the 1.4G thinking it would be at least a little step forward. Unfortunately, I've found myself disappointed more often than not. I haven't changed bodies, and I haven't changed techniques. This is what led me to wondering if there was an issue with my lens. I'm quite interested in the ability to make fine adjustments and am looking forward to giving that a try. <br /> Rodeo Joe - Sorry, thought Dropbox would be easier for most users. I'll attach here.</p><div></div>

[carl_s]

<p>Original #2 Cropped</p><div></div>

[carl_s]

<p>Shot with tripod 1/200s f/4.0. Significantly better, but a lot smaller aperture and twice the shutter speed. </p><div></div>

[ShunCheung]

<p>I think there is motion blur in the image attached to the post from 6:27pm: http://static.photo.net/attachments/bboard/00d/00dflX-560098684.jpg<br>

1/100 sec is probably insufficient to stop a child's movement.</p>

<p>As I wrote earlier:</p>

<blockquote>

<p>And a better way to test sharpness is to put your camera on a tripod and use live view to manual focus. Depth of field at f2.2 is narrow. Any slight focusing error will throw off your results. </p>

</blockquote>

<p>Another important point is that you need to use a static test subject to check sharpness. Any human or animal, especially a child, is a poor subject matter for that purpose.<br>

<br>

From the last three images, at least I see no evidence that there is anything wrong with your lens.</p>

[carl_s]

Very good, thanks Shun (and everyone else). That's

what I was looking to hear. Have a nice night all..

[rodeo_joe1]

<p>Yes, definitely subject or camera movement in "Original #1".<br /> Looks like a bit of front-focussing and maybe a touch of motion blur in "Original #2" as well.</p>

<p>Good advice to test the lens properly on a tripod and with a static subject, using magnified Live View to focus of course. Also do a bit of focus bracketing to ensure you're getting the best possible image from the lens. Depth-of-field is virtually non-existent at f/1.4 and viewing a 100% image.</p>

[ShunCheung]

<p>Carl, please don't just listen to me alone. I merely took a quick look at your images, and it is very much possible that I overlooked something. You also don't draw any final conclusion merely based on 3 images.</p>

<p>As I said, re-check that lens with a better test procedure to make sure that you are satisfied. Others may observe something I don't. I happen to have very bad experience with refurbished Nikon lenses. I have the impression that I just got unlucky 3 times, but I would certainly check a refurb lens very thoroughly within the return period.</p>

[michael_bradtke]

<p>Minimum shutter speeds are always very subjective. A lot depends on the photographers techniques and on how much subject movement there is. For shooting free range kids in low light I would want a higher shutter speed then 100</p>

<p>But unless I absolutely had need for the 50mm f/1.4 G I would pass it buy. It is known to be not as sharp wide open as the 50mm f/1.8G. Check out the lens tests and then shoot them side by side. Shooting a resolution chart as well as in real life the 50mm f/1.8 is sharper wide open then the f/1.4. Around f/3.5 to f/4 the lenses are equal </p>

[carl_s]

<p>So here are two images using Nadeen Flynn's focus chart. The first (AF in title) was taken using magnified live view autofocus. The second (MF in title) was taken using magnified live view manual focus. LR sharpening left at the default value of 25, no other noise reduction, clarity, or contrast adjustments were made.<br>

The two photos look virtually identical to me, which I think, would indicate that the AF system is working just fine. Focus falloff appears to happen somewhere around the 2 mm mark, and to me, seems roughly equal on both front and back ends. <br>

Now I am probably being over the top, but while "This text should be perfectly in focus" is definitely in the middle of the depth of field, the level of visual acuity doesn't seem to be all that great. Perhaps that's just a factor of doing so much pixel peeping... In a print I'm sure it would look great. Kinda wish I had more lenses for comparison's sake. <br>

Also, I've not used zoomed Live View before. Is this a technique that you guys are using regularly when shooting to pinpoint focus? Have a nice day all...<br>

Carl</p><div></div>

[carl_s]

<p>Manual Focus Shot</p><div></div>

[SCL]

<p>FWIW the image is spot on from a focus standpoint, but the image is definitely soft, not crisp as one would expect. If you stop down the lens 2 notches from wide open and still get less than razor sharp across the plane of focus, I'd return the lens.</p>

[carl_s]

<p>At f/2.5 it's a lot better (attached). I think I probably just need to take more care when taking photos of "free range kids." Fantastic line Mike...<br>

I posted this follow up primarily for anyone who might come across the thread down the road.<br>

Thanks for your help all..</p><div></div>