D3200 Backfocus Fix

I just bought a D3200 as a lightweight backup for the D800 on an upcoming hiking trip.  Resolution at 24MP is great when used with Nikon’s best glass, but I was very disappointed when the D3200 turned out to have a bad case of backfocus right out of the box.  Not only the kit lens, but all of my other Nikon lenses also exhibited the same backfocus. D3200, being an entry level camera, does not have the focus finetune function. There was not enough time to ensure that Nikon would get a readjusted unit back prior to the trip and since the D3200 is scarce, a replacement was not feasible either.

A search on “fixing back focus” yielded the site http://leongoodman.tripod.com/d70focusnew.html, which has a rather complete treatus on the whole focus issue, including how to fix it on Nikon DSLRs.  After reading through the material, I decided to give fixing the problem a try.  Basically, Nikon has provided a couple of mirror stops in the mirror box that control the final position of the main mirror and the secondary mirror used for focus.  These stops are adjustable and control viewfinder focus and autofocus separately.  As Leon explains, these stops are set during assembly to nominal positions and the camera’s computer settings complete the fine focus during final adjustment.

Checking the manual focus with a 50mm f1/4G indicated a manual front focus problem in addition to the auto backfocus issue.  Following Leon’s simple procedure, I was able to adjust the manual focus first and then the autofocus.  The only thing different for the D3200 is the use of the “Mirror Lockup for Cleaning” function in place of manually raising the mirror.  Only small adjustments were required to bring both the manual and auto focus back to the proper positions.  The adjustment cams only had to be moved about 1/20 of a turn.

Checking the other lenses showed that the auto backfocus issue had been resolved.  The images below show the before and after results for the 50mm f/1.4G as well as the adjustment of the focus mirror stop. (Care must be taken not to touch the sensor assembly!).  Sending the camera back to Nikon is probably the best approach, but in an emergency this approach works well.

Original Backfocus

After Adjustment

Adjustment of mirror stop

 

D3200 vs D800

Comparison of resolution of a D3200 vs. a D800.  The cameras were set up on the same tripod, at the same location, with the same lens – Nikon 50mm f/1.4G @ f/8 ISO 100.  I wanted to test the system performance showing the same subject area at the same distance.  The objective of the comparison was to see how well the D3200 will perform as a back-up to the d800 in a real world situation. Since the D3200 has a finer pixel pitch, one would expect as good or better detail from the D3200.  This ignores the crop factor and just looks only at the ability to render detail for a given lens.   Overall a D800 image will have more image information than the D3200 (36MP vs 24MP), but the subject detail is what I am looking at here.

The test was performed by using the same tripod position, same 50mm f/1.4G at f/8, ISO 100, 1/200s raw capture.  The images were processed in LR4 and PS, sharpened 60%, radius 1.0, brightness and contrast tweaked slightly to equalize images.  The images were cropped to show the same subject area.  Any final image detail difference would then be primarily due to the sensor resolution and AA filter. Several images were made with each camera, the best of which was used.  Focus was LV and auto.  D800 showed no difference in focus, but the D3200 LV was much better.

Three crops from the center are shown:  D800 at 455×388 pix, D3200 at 569×485 pix and an upsized D800 crop at 569×485 pix, 1.25x enlargement, which is the same as the ratio of pixel pitch between the cameras.  To me there is very little difference between the details shown, with perhaps a slight bit more with the D3200. Click on image for full sized crop.

I am very pleased with the D3200 as a lightweight backup that takes all of my lenses.  I am not pleased with the back-focus issue, especially since the D3200 does not have focus fine tuning.  I guess the D3200 will be going back to Nikon. Thanks for looking.

D800 Crop D3200 Crop
D800 Crop resized to match D3200 crop

 

Geotagging

Location tagging your photos is a great way to aid in sorting out all of those images from a long trip.  My experience with a third-party geotagger on the Nikon D800 is detailed in my EasyTagger review.  The EasyTagger GPS proved to be a very workable and not too expensive addition to my D800 travel kit.

New Web Site

I am launching this new website, concentrating on images, presentations and other writings on photography, to collect the large volume of stuff I have accumulated.  The image galleries will be augmented and any new writings will be added as they are developed.  In the blog I will discuss current items of interest.

Please let me know what you think and how I can improve the site and its contents.

Al Peter

Transit of Venus

The evening of June 5th will bring a very rare event – the transit of Venus across the disk of the sun.  This phenomenon will not repeat for another  105 years!  It is possible to observe and photograph to event, but with extreme care!  Please read the article at the following link, before attempting to either view or image.  If you have a solar filter, give it a try.

http://www.skyandtelescope.com/community/skyblog/observingblog/How-to-Photograph-the-Solar-Eclipse-and-the-Transit-of-Venus-149902015.html

D800

I received my D800 almost two months ago (03/30/12) and have had the opportunity to use it on several outings.  My impression is that it lives up to the speculation about its performance.  The files are very large and detailed, but offer no particular problems in post processing.  Lightroom 4 takes a few moments more to load the files, otherwise everything else is normal.  Some specifics:

  • I shoot in RAW, converted in LR (14bit, compressed) – the files are about 40MB, which works out to more than 600 images on a 32GB CF card (Sandisk Extreme 60MB/s).  Battery life is also greater than 900 images, depending on review, etc.
  • For me, handling is great.  Most of the buttons are in familiar places compared to the D300s, except the focus controls,which use the front and rear dials, activated by means of a small button on the left front.  This was one of the few things I had to refer to the manual about.
  • Much discussion is flying around about the redesigned right hand grip.  For me it is an improvement over the D300.  Even though the D800 is about 3oz heavier than the D300, it is very comfortable to hold and carry.
  • The images using a top quality FX lens are very detailed.  The ability to crop extensively means that each image can produce several different interpretations of the shot, created at leasure in post processing.  The lenses I have used so far are the Nikon 24-70 f/2.8, Nikon 17-35 f/2.8, Nikon 24-120 f/4 VR, and the Nikon 70-300 VR f/4.5-5.6.  In addition, I just received a Rokinon 24mm f/2.8 manual focus (which will be discussed separately).  All of these produced excellent results when used on a tripod or with higher shutter speeds.
  • Exposure control is excellent, if about 1/3 stop over-exposed.  Dialing in -0.3 took care of that.  Only slight tweaks in LR were needed to bring up shadows or bring down highlights.  The images appear to be quite forgiving and capable of a lot of adjustment to taste.  LR4 can easily bring down the apparently over-exposed highlight and recover lots of detail in the shadows.
  • The Auto ISO mode appears to work very well, and is easily turned on or off using the dials.
  • With the wide angles, the level and tilt indicators are great and easily controlled using the front FN button.
  • Video is interesting, to say the least.  I shot a full length musical production in 1080p, processed in Adobe Premiere.  the lighting was awfull, but the auto ISO worked great, with excellent images up to ISO 3200.  The only problems with video are zooming anf focus.  Auto focus is not very good at all.  Prefocus is a must, since the autofocus at the light levels for the production was very slow and uncertain.  Compared to a mid-range Sony camcorder, the D800 images are sharper and with less noise.  The 20 min. limitation on recording time was also a pain.  Overall the result was very good, but achieved with some difficulty.
  • For still photography, the D800 is a joy to use and well worth the extra expense and file size handling.

Some sample images are shown below.  Most are available in full size (7360×4912) as well as 100% crops of the center. The 1500×1000 images have been down-sampled for ease of viewing.  The full size images are available at the link below the image.  All were shot as RAW 14 bit compressed and converted to JPEG in LR, sharpened in LR with radius 1.0 @ 90%.  Click on a thumb to view.  The full size JPEG images are 15MB+ files, so they may take a few seconds to load.

Eden Park 1500x1000 N24-70 @ 70mm f/5.6

100% Center Crop

Water Tower 1500x1000 N24-70 @ 50mm f/6.3

100% Center Crop

Eden Park – Full size 19MB Water Tower – Full size 22MB

Water Tower 2 1500x1000 N24-70 @ 48mm f/5.6

100% Center Crop

Gazebo 1500x1000 N17-35 @ 30mm f/5.6

100% Center Crop

Water Tower 2 – Full size 19MB Gazebo – Full size 22MB

Alms Park 1500x1000 N17-35 @ 25mm f/5.6

100% Center Crop

Tulips 1500x1000 N70-300 @ 70mm f/11

100% Center Crop

Alms Park – Full size 19MB Tulips – Full size 22MB

Riverfront 1500x1000 N24-70 @ 60mm f/5.6

100% Center Crop

Bridge 1500x1000 N24-70 @ 24mm f/5.6

100% Center Crop

Riverfront – Full size 19MB Bridge – Full size 22MB

Riverfront Park 1500x1000 N24-70 @ 24mm f/5.6

100% Center Crop

Riverfront Park 2 1500x1000 N24-70 @ 38mm f/5.6

100% Center Crop

Riverfront Park – Full size 19MB Riverfront Park 2 – Full size 22MB

New Look!

New Site for Al Peter.

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