Nikon D7100 And The New 24mp sensors

Posted on Updated on

img_05The entire line of DX Nikon cameras are now at 24mp so what’s the deal with all those pixels?  I’m going to talk about the Nikon D7100 a camera that I own. first off you might want to see my post on dealing with High MP camera files. I really don’t notice any difference in LR between 12mp and 24mp as far as processing speed (except for importing and exporting). When I export I usually downsize to 12mp so no problem there as well, I do this because 24mp is just too much with my computer and Paint Shop Pro when using layers. Compared to a Full Frame camera the D7100 is still noisy at higher ISOs  even if it can in the right conditions almost match the D700/600 for example with some noise reduction but as soon as you start processing the image (increasing  the exposure or lifting the shadows) noise starts to increase at a higher rate than the FF files. Even though most folks don’t need 24mp we really don’t have much choice  these days but we still have an advantage with these sensors when the file is downsized or viewed at normal screen sizes. Now, my D7100 is a little cleaner up to ISO 3200 then my D90 (only goes to 3200) when viewed at 100% but when I downsize the 24mp file to 12mp then I realize a nice improvement in noise and to some extent sharpness as well. The AF on the D7100 is much better as well so having sharply focused images is the most important thing we have, there is not much that is worse than a high ISO image that is out of focus. The lack of an AA filter does make for improved sharpness at 100% on screen viewing and to a lesser extent improved local contrast with most lenses and particularly with primes. I think the Sony sensor from the D7000 is a better sensor overall (better balance of mp and noise + lack of any banding and color casts) and better suited to todays DX lenses, I would rather Nikon had used that one without an AA filter and maybe some tweaking here and there. There really has not been all that much progress in Cmos sensors since the D3s, just more MP and a bit of tweaking. The Sony sensors are still the best. The D5200/7100 use a Toshiba sensor. The bottom line is that the D7100 is all I need to take and create images for some time. Would I like to have a few FF cameras and the best lenses? Oh Yeah, but that costs a whole lot of money and chances are viewers wont’ notice any difference in my output anyway.

Update: Now that I am using PSCC I find that I can use the full 24mp files without any noticeable lag using layers and brushes which is a problem for Paint Shop Pro (layers and a large brush is almost usable on my 4yr old quad computer).

Remember that a 24mp printed image is only 40% bigger than a 12mp printed image in linear dimensions. How is that? well if a 12mp files makes an 8×10 (example only) then you would need 4 8×10 images to fill the space a 16×20 would take. S0 to get a print double the size of your 12mp camera you would need 48mp! 40% is not that much of a gain. The higher the mp the greater the gain to go bigger again. So if you have a Nikon D800 (36mp) and want a 40% bigger print from it you need 72mp! that’s right 72 mp. Going from 6mp to 24mp actually gives you a print double the size. So the next time you start dreaming about going to 36mp from  24mp consider that there is only about a 20% gain in print size. A real wake up call. Also for each increment in mp the gain is smaller as it becomes a smaller percentage of the overall size, for example going from 12-24 than to 36mp then to 48mp with the last 12mp jump yielding about a 22% jump in linear dimensions  (my math might be a bit off).

Okay so here are my thoughts on some issues and observances. This is not a review.

1. Buffer size: this is really not the issue people have made out of it.

FYI. Going from a 45MB/s card to a 95MB/s card makes a big difference and I assume that even faster future cards will add even more shots to the D7100’s high-speed continuous shooting before slowing down.  With a 45MB/s card the camera literally stops shooting after the buffer fills up and you have to wait several seconds before you can shoot again. With the 95MB/s card you go from 6 fps to 2.5 or so fps in DX  mode @ 14bits, this is totally workable for me. Jpegs of course give  more shots before the buffer fills and will allow you to use a slower card.

If you need more speed note the following info. Once the camera slows down you get better than 3 fps in 1.3 crop mode.

 A DPR poster posed his tests results.

” I’ve received the SanDisk Extreme Pro 95MB/s  today (16Gb) :

Rate + number of pics before slowing down (with card empty, just formatted) :

1.3x, 12bit, compressed : 7fps / 19-20 pics
1.3x, 12bit compressed lossless : 7fps / 15 pics
1.3x, 14bit compressed : 6fps / 15-16 pics
1.3x, 14bit compressed lossless : 6fps / 9 pics”


Things really aren’t as bad as it first seemed and is likely to get better with future generations of cards. 7 fps is quite fast. Many folks do quite a bit of cropping for sports and wildlife shooting so the 1.3 crop mode should not be much of a problem in many situations.
I would assume this info applies to the FF camera bodies as well, particularly the ones with a DX crop mode.

Note: there are other brands besides SanDisk I’m just not sure about the speed comparisons.

2. Banding from pushing shadows and crushing blue continuous tones.

You may get horizontal banding in some situations if you push your underexposed shadow areas enough.  I don’t see this with D90 or S800 files so this seems to be another short coming of the Toshiba sensor in the blue channel. Note: you may never notice this in real world shooting unless you do some unusual processing. This artifact is the same (with slight variations) in a variety of convertors from ACR / LR 4-5 / PSPX5-6 / View NX. Also there are reports that this sensor may not be the  best choice for night photography due to the higher incidence of banding particularly at higher ISOs, on the other hand some folks who do night photography have reported not ever seeing any banding.  The banding is not much of an issue at all except for a rare few but even then the banding can be removed with software.

Note: Shadow banding is easily fixed with the De-banding tools found in Topaz De-noise or Nik’s Define 2. You do not need to have any noise reduction applied to use the De-banding tools. In extreme cases you can run the image thru more that once. You can expect 90-100% reduction of banding from the first pass in most cases. Now with that out of the way the D7100 has very good DR and you can push the shadows quite a bit. 14 bit raws give the cleanest shadows.

Sky banding (posterization) is not fixable to my knowledge so avoid heavy processing of clear blue skies (blue channel) or pick days with less clear skies for your projects. I have only  gotten this a few times in the last 2 years , the conditions have to be just right. Again this has only happened twice to me and this included a gray background in studio use but for that it only happened on one shoot and I have no idea why. Raw – 16 bit tiffs. Ligthroom 4-5 and PS CC or PSPX5-6. The only factor I can think of was the use of a high speed card I have for sports. I have not seen it since changing cards but don’t see any reason why that would be the case. Posterization is not a known issue for this sensor so I would not worry too much about this.

3. Color Casts within pushed shadows.

It’s there but in real world use its has not been an issue for me, and if it is I know how to fix it. Here’s what I found.

ISO 100, a touch of green in shadows.

ISO 200, the highest green of any ISO.

ISO 400, the most neutral of any ISO.

ISO 800, from here purple starts to get progressively worse as does noise and reduced DR.

4. Photos have yellow or green tint.

I’m not talking about the LCD screen which when new may have a bit of green cast until the adhesive cures just as it does in iPads. All the newer generation of Nikon Cameras seem to have less magenta then the D90/300/3 generations of sensors. You can adjust the camera’s WB in more depth by going to WB in the menu (not the info area) and getting to the color grid then adjusting all four parameters compared to just two in the WB from you Info button. If your still not satisfied you can make your own profile using the free DNG profile editor or just make some presets using the HSL tools. Another quick fix is to just apply a bit more magenta with the tint slider. Your raw converter may vary here depending on which one your using (Nikon Veiw and Capture NX don’t have this shift), and there could also be some updates or tweaking later on that will refine the color even more.

5. The lack of an AA filter makes this a much sharper camera.

Sorry that’s not as true as some are making it seem. Yes at 100% viewing with the best lenses at the right aperture will make for some amazing detail ( some what sharper) but once you leave those parameters the difference is lost compared to another camera with a weak AA filter like the D5200 with the same sensor that has a weak AA filter. Still there seems to be a sense of increased local contrast and acutance (is it real?). Both cameras can show excellent sharpness.

6. There are no lenses that can resolve 24 so why bother.

That is very true at the wider focal lengths there is not anything at 10-18mm that can do even 15mp justice at the edges or corners let alone the center. The Nikon 14-24 will come closest at the wider end and maybe the Zeiss 15mm. We really need some decent wide primes and updated ultra wide zooms. The Tokina 11-16 F2:8 or 12-24 mk2 seems to be the best at the moment from what I can see (I don’t own it though). From 18mm up we are doing better and with the current generation of primes we have really excellent IQ. Even kit lenses are starting to get better with the introduction of the 18-140 vr and new 18-50.  any lens will benefit from higher MP sensors even though they can’t resolve all the MP of the sensor. They will show better detail or a least a better larger file then you could get with the smaller MP camera and uprezing, and once you downsize the file the IQ tends to increase compared to just shooting the image with the lower MP camera. You will however notice more lens flaws at 100% viewing. Keep in mind that 24mp in DX is the same as 54mp in FF so there is more stress on the lens which is why wide angle has such a hard time (wide angle has always been difficult to get right). With the wider end of zooms your likely to notice the areas within the image that are not sharp, this is normal for zooms and may change somewhat with every shot as you move the lens and change focus and zoom with distance. A whole new generation of zooms need to be made for DX now. My Nion 12-24 does well at close distances with 24mp but not for landscapes I see just too much softness in the edges and corners for my taste. Downsizing to 12mp shows what I got from a 12mp camera which was never excellent IMO. If you can afford it FF is the better deal long term unless you need the crop factor or are good with what you get now. Don’t count on Nikon or Canon to supply you with more pro grade DX primes or zooms they want you to upgrade to Full Frame.

7. The build quality is much better then previous Nikon DX cameras.

Yes is does have better weather sealing and internal build quality but from just handling the camera I can’t tell the difference, they all feel like a light  plastic camera to me. It’s just the shape and weight that I notice. Did you notice that the weakest part of the camera is still not magnesium ( bottom of built-in flash in front and part of the main body).

8.  Pro AF from the D300 is much better than other consumers bodies.

Yes this time I do agree that the AF is much better than my old D90. Add fine tune and you can use large apertures with consistently sharp images at the point of focus. The AF/AE button is much better positioned to be used as AF-ON which pro bodies have a dedicated button for. Many pros only use the AF-ON button rather than use the shutter button for focusing.

9. Video is soft according to some reviews.

Maybe compared to the best but you can be sure that overall you’re going to get better video than older camera bodies. If your really into video you need a real video camera to which there are many larger sensored versions out there now. I have also read that some think the Video is better than the D600. The D4 had terrible video when it first came out (might be better now). The D800 is probably the best DSLR from Nikon for video.

10. Instant 100% viewing on the LCD.

This is one feature that I don’t want to be without now that I have been using it. You just program the Okay button to show a 100% view for instant feed back of focus. No more pushing the + button 6 times. Saves you time and folks don’t see you spending so much time checking (more professional). All cameras should have this feature.

11. Dual cards slots

Although I have never had a card fail on me in 6yrs I can see the value of two cards slots. You can also use the second slot for added capacity instead of back up. It probably cost Nikon $1 to put this in so I feel all mid range and up cameras should have this.

12. 24mp files slow down post processing too much.

Believe it or not that’s untrue. if you shoot Jpeg then you can just change the size of your Jpegs anyway.  For raw processing your making changes virtually (Jpegs as well) and not actually affecting the image itself so with LR I really don’t see much if any difference from my 12mp files. Now as always with LR you want to make sure you leave the lens corrections off until last or it will really slow processing down, particularly with the adjustment brush. I can have over a dozen layers on an image and not have any problems with my 4 yr old quad core  machine and 8 gigs. You can make exporting presets to resize if you want for Photoshop work or to access plug-ins from within LR after exporting to another folder or back into the same folder as 16 bit Tiffs. That takes a bit more time but not much. If your only working on a few images than you can just leave it full size. Once you go to export than your going to have to wait longer for the 24mp files. With one of the newer fast computers you shouldn’t have any issues with 24mp files.

13. Flash Misfires.

I have noticed this on 3 bodies and others are reporting this on forums. This seems to be some compatibility issue with certain flash units. What happens is occasionally you will get a low output flash pop in TTL mode only. I never  get a misfire with my SB800s but with an SB910 I did notice it on almost every shoot. Some others are saying the SB600 does this also.  I suspect this is something that most folks would not necessarily notice unless they were looking  for it. At first I though it was just the flash unit. I wouldn’t worry too much about this but it is worth testing for if you purchase a D7100. If your D7100 does this and you really want to keep it then concider changing flash units until this gets taken care of.

14. Odds & Ends.

Lock button on the program dial now prevents accidental changes. U1  & 2 is handy if you have never had it. New i button give short cuts  to some features. Controls for video exposure now located on the LCD.

Grips are so overpriced that I decided to try out a cheaper after market one (Meike) I had to send it back as the top mounting plate is too thin and flexes so much that with very little effort you can slip a dime into the area between the camera and grip. I wouldn’t trust hanging my camera from a Black Rapids strap using that grip at this time. So I may just wait for the price to come down some and get the Nikon or maybe  try another higher end after market version (yes there are higher end version for some cameras with magnesium in them, look at Phottix).

I think grips are really under utilized. Just think of all the options a grip could offer that the camera does not have. The camera would have to have the ability to communicate with the grip though.

For example:

Remote control capacity.
Increased buffer capacity?
Increased frame rate?
Wireless image transfer/ tethering
Other connections found on pro cameras.
Video options for better microphone and sound control.
Options for more custom user data banks like U1-2.
USB connect for auto updates.
Better fit with the camera so the grip looks more like its part of the body instead of an after thought.

You can probably think of a bunch more.

Actually if you consider how much Nikon charges for a built-in grip the screw on types are really a bargain, even the $450 D800 version.

D700 -D3 almost $2500 for that grip.  Same 12mp sensor and features. Only the D3S had a real world advantage. D3X (24mp version of D3) was way over priced, and still is.
D800 -D4 almost $3000 for that grip.  36mp vs 16mp. 36mp is cheaper. Big profits for those grips.  You could say the bodies cost more due to lower manufacture volume but that is only because Nikon jacks the price way up for the privilege of having a built-in grip. there should only be a $300 premium for those that want a full sized body with built-in grip, anything over that is just making lots of profit. Think about it, the grip is nothing high tech at all, it just holds batteries and has a switch or two and maybe another small LCD info window.

Other than the grip the cameras are not that different in the cost to produce.