What Is The Highest ISO I Should Use For Portraits?

Question:

What is the highest ISO I should use for portraits on the Canon 5D mk2?

Today I’ll be expanding this question to include a general response for ALL cameras currently on the market, and some of the more popular cameras that have already left the market. There are a number of factors that go into “what is the highest acceptable ISO for my camera?” so I will have to lay out an explanation of my standards and a few other considerations before I get to the whole answer.

Basically, today I am going to talk about which ISO’s I would find to be acceptable for professional work in traditional portraiture or wedding portraits / formals.  So for example while I might go even higher during a wedding ceremony or reception, what ISO can I use to get wedding formals in a dimly lit church, or on a beach at sunset, and still deliver the quality of images that can be used for large printing without any noticeable loss of quality compared to if I had shot at my base ISO?

Answer:

Honestly if you’re just trying to document something or take a random portrait of friends doing something fun, every ISO that your camera has is worth using.  Many cameras have one or two “HI” ISO settings that become progressively more horrible and un-usable for large prints, and what I would definitely consider “un-deliverable” in a professional capacity.  However they still get the job done, if all you’re ever going to do is tag your friends on Facebook.  ;-)

By the light of the full moon – Joshua Tree NP
Captured during filming of the timelapse film “INTERVALS”
Canon 5D mk2, Canon 24mm f/1.4 L mk2
1/10 sec, f/1.4, ISO 25600, hand-held

Sure, if you zoom in and pixel-peep at your absolute highest ISO, it will look like mush.  But that’s fine if all you need is a ~1000 pixel image for the internet as a “goofing around” photo, or maybe as a more serious “proof of concept” type image for learning purposes.

Before we go any further, I’d like to dwell on the notion of “goofing around” for a moment.  Simply put, isn’t this partly what cameras are for?  Who said it was not okay to just entertain ourselves with photography?  If you ask me, people who take photography totally seriously 100% of the time are missing out.  Yes, there is a time and place to pixel-peep and worry about the sharpness and detail of all your images, but if you don’t ever have fun with photography you might burn out.

Oppositely, if you are indeed a huge pixel-peeper and you bought yourself a 20-30+ megapixel camera and you barely go above ISO 400 because you cannot bear to lose any more image quality, well then I hope you’re regularly making very huge prints with your images and not just sharing 900 pixel versions on your favorite forum community etc. ;-)

Of course who am I to tell other people what they can and cannot do with their cameras?!  I’m just giving my opinion for those who are looking to have fun and be as creative as possible with photography, and discover how far they can trust their cameras to deliver professional results.

Reasons To Use High ISOs For Portraiture

So we’ve established that you’re a professional portrait or wedding photographer, or you’re a hobbyist who wants to make a sizable print with professional standards.  What then? Why not shoot everything that is truly important at your lowest ISO?  There is very little that a tripod and studio lighting equipment can’t overcome. Well, it just so happens that on-location portraiture often falls into that category of “very little”.  True, you could put your camera on a tripod and then set up enough flashes to light up a whole cathedral if you wanted to, but doing so would take a lot more time to set up than you usually are given for such things.  If you have the time and/or the light to shoot at your lowest ISO, then more power to you.  However if not, keep reading!

When shooting at very high ISOs in very low light, it essentially all comes down to this: Finding a balance of image noise / detail, depth of field, and of course shutter speed related blur risks.

Using High ISO’s For Depth Of Field

Let’s say for example that you are able to shoot hand-held at ISO 200 or 400 at f/2.8.   However if you have five rows of people in a crowded, dimly lit church then there is a good chance that f/2.8 will not get everybody perfectly in focus. Or your lens simply may not have sharp edges at its widest aperture, especially if it’s a faster prime or an older f/2.8 zoom.  (I’ll have to write a whole different article regarding wide angle zooms and field curvature / edge sharpness!)

In this case you might want to raise your ISO so that you can hit f/4, f/5.6, or even f/8+ if necessary.  Any landscape or fashion photographer may cringe at the thought of raising your ISO just to be able to shoot at f/11 hand-held, but any fellow wedding / portrait photographer will understand this dilemma.

So, pay attention to your depth of field when shooting large groups in low light, and don’t be afraid to crank your ISO up when necessary.

Using High ISO’s To Eliminate Motion Blur

The other thing portrait photographers run into is the simple fact that their subjects are moving.  Even a portrait of people standing perfectly still cannot be shot at a shutter speed much longer than about 1/60 sec for very large groups, or for more artistic, creative images of a couple by themselves you might be able to pull off 1/2 or 1″ shutter speeds.

[Rewind: Tips for shooting slow shutter speed portraits!]

So instead of yelling at everybody in a group photo to hold perfectly still, consider raising your ISO to eliminate subject motion blur.  Usually for non-squirmy adults, 1/60 or 1/100 is sufficient, or to be on the safe side maybe 1/200 sec.

Even if your subjects hold perfectly still, you still need to worry about camera shake as well.  If you shoot your formal portraits from a tripod you can definitely coax a much higher keeper rate from any camera.  Many portrait photographers think that using higher ISO’s (or always shooting wide open) is an excuse to never worry about using a tripod, but in my experience there are plenty of situations in which both a tripod and high ISO’s are necessary.  So, just keep this in mind!

Nikon D700, Nikon 85mm f/1.8 G @ f/1.8,
1/2 sec, FotoPro C5i Tripod, ISO 3200, 2X wireless flashes

List Of Camera High ISO Usefulness

Alright, let’s get to it:  Which camera do you own, and what is the highest ISO you can safely use for the best quality results?  I understand that everyone has their own standards of acceptable noise / detail, so I will give two numbers as an overall range.

The main goal is to find an acceptable increase in “grain”, without losing any noticeable image detail for, say, an 8×10 or 11×14 print.  At this print size, the difference between your lowest ISO and your highest acceptable ISO should actually be very marginal.  If you regularly need to make 20×30″ and larger prints with your portraiture, maybe knock ~1 stop of ISO off these standards for the most formal of family / group portraits, but not necessarily the creative, artistic portraits of just 1-2 people.

Full-Frame Camera High ISO Comparisons

• Canon 5D mk2, Canon 1Ds mk3
  These two Canon DSLRs share a nearly identical 21 megapixel sensor, and are almost on par with even the latest Canon DSLRs.  (According to DXOmark.com, almost all full-frame Canon DSLRs’ image quality is within about 1 stop of each other)  Feel free to shoot with these cameras at ISO 800-3200 even for important portraiture, as long as you don’t under-expose your images.

• Nikon D700, Nikon D3
  These are Nikon’s first-ever full-frame DSLRs, but the 12 megapixel sensor they share is still a gold standard in high ISO image quality for working pros.  I shoot very important portraits at ISO 1600-3200 without hesitation, and even go as high as ISO 6400 for general journalism / action work or the occasional portrait at twilight. Again, just be sure to nail your exposures because those highest ISO’s will indeed get a little “iffy” for professional printing if they are even the slightest bit under-exposed.  Bonus:  The Nikon D3s can push this envelope about a stop higher than the D3, if you’re good with exposures.  The D3x, on the other hand, should be kept at similar or lower ISO’s compared to the D3.

• Canon 5D mk1, Canon 1Ds mk2
  These two “classic” full-frame cameras are a little older than the Nikon 12 megapixel bodies, yet are still seen here and there.  Their ISO performance is only considered an accomplishment for their time; in my experience even many of today’s better crop-sensor DSLR’s are starting to beat them at low-light image quality.  While general (professional) candids and documentary photos might be acceptable at ISO 1600-3200, I wouldn’t go any higher than ISO 400-1600 for really important portraits.

• Nikon D800, Canon 5D mk3
  In my opinion, both of these cameras don’t gain much more than a single stop worth of usable high ISO performance compared to their predecessors.  In other words if you’re really struggling with a camera like a D700 or a 5D mk2 and are considering upgrading to either of these newer bodies for the ISO quality alone, think again.  (There are many good reasons to upgrade, ISO performance just isn’t the main factor to me.)  The bottom line is that I still wouldn’t go much higher than ISO 1600-3200 for important photos, although unlike most predecessors I might consider using these cameras as high as 6400-12800 for professional journalism / action.  In a pinch, that is, and your own standards may vary.
• Canon 6D, Nikon D610
  Unlike the D800 and 5D mk3, these two cameras do gain a whole stop or more of usability.  The 6D in particular delivers some incredible results, when using healthy amounts of noise reduction.  Expect decent results for decent sized prints even from ISO 3200-12800, and marginally acceptable images for general candids at 25600, although you really must be careful at that point.  The D610 (and Nikon D600 of course) does come close, but I can’t really recommend going much higher than 1600-6400 for most professional environments.  Not only is noise a factor, but the fantastic dynamic range from your lowest ISO also starts to fall behind Canon at higher ISO’s.
• Canon 1DX, Nikon D4
  Why you’re using these cameras for general portraiture I cannot imagine, since any of the four previously mentioned DSLRs make much better choices.  Having said that, you can indeed use these cameras at some incredibly high ISO’s.  Not necessarily any higher than the 6D or D610, (which cost a fraction as much) but still the results from the same ISO’s will look a little bit cleaner and therefore might print a little larger.
• Sony A900, A850, Sony A99
  Sony’s current full-frame options are all based around a 24 megapixel sensor, (until their new mirrorless full-frame system hits the market!) …and there is a significant difference between the older model sensor and the newest one in the A99. Simply put, the A900 and A850 perform poorly at high ISO’s and shouldn’t be used much higher than ISO 800-1600 for very important portraits, while the A99 produces results similar to the D600: acceptable up to 1600-3200, and maybe 6400 if you hit your exposures and get generous with noise reduction.

Crop-Sensor High ISO Comparisons

Since there are innumerable cameras in the crop sensor DSLR market, I think it would be better to rank them by year, and maybe only mention a select few cameras.

• 2012 to Present – Crop Sensor DSLR’s
  The latest generation of crop-sensor DSLR’s are delivering some pretty incredible results.  All of the ones I’ve tested or seen test images from are totally usable to at least 800 even by the most strict standards, and up to 1600-3200 depending on just how strict.  The Nikon 24 megapixel DX sensor, (Nikon D7100, Nikon D5200) delivers surprisingly good results that is essentially just ~1 stop behind most full-frame cameras.  Similarly, Canon’s latest 18-20 megapixel crop-sensor DSLRs (Canon 70D, Canon 700D) are definitely acceptable to a pro from ISO 800, and up to 1600-3200 depending on your standards. Similar results results can be had from any other brand of 1.5x crop camera from Pentax or Sony etc, and the ~2x crop mirrorless systems are also producing stunning results from ISO 800-1600 for almost any professional’s standards.
• 2009 to 2012 – Crop-Sensor DSLR’s
  This generation is still relatively new, and any crop-sensor DSLR from these years is going to be similarly acceptable to around ISO 800, although depending on the camera I might refrain from going much higher than 800-1600.  Cameras like the Canon 7D and Canon 60D are usable for general shooting up to ISO 3200, but be careful if you’re planning to print larger prints from these ISO’s.
• 2008 And Older – Crop-Sensor DSLR’s
  The oldest DSLR’s in this range, the <6-8 megapixel category, are risky business any higher than ISO 400-800, especially the pre-2007 Nikons.  However the closer you get to 2009, (Nikon D300, Nikon D90, Canon 40D, Canon 50D) …the more you can trust ISO’s up to 800 or so.

Nikon D700, Tamron 17mm f/3.5 SP,
Fotopro C5i Tripod, 2X wireless flashes,

Conclusion

Everybody has different personal standards, however in my opinion most people don’t realize just how capable their camera can be when they pay attention to lighting, exposure, and general camera / subject stability.  Yes, upgrading your camera will give you more flexibility and “room for error”, however with great technique and flattering, good quality light, I see no reason why not to shoot even very important things like bridal portraits or details in extremely low light using an ISO that you are only barely “comfortable” with using. For portrait sessions in general (from kids to families to engagements) I find that the most beautiful times to shoot are actually just after sunset, yet I always see other photographers packing up their gear and heading home just as the light is getting gorgeous.  I hope this article encourages you to expand your potential shooting conditions and capabilities, and to think twice about blaming poor results on your camera alone!  ;-)

Take care,
=Matt=