Jump to content

Model Photography - Reasonable F-stops?


Recommended Posts

I’m wondering if anyone with more knowledge/experience could comment on a reasonable F-stop range for photographing models?

 

I have a decent Nikon DSLR and do most of my photography for models with the 18-55 mm lenses (F3.4-5.6). I have two CFL photography lamps with approximately 8,000 lumens, CRI 93, 5500k. Although I did just order a new tent inclusive of LED lights at 13,000 lumens, CRI 95, 5000k. 

 

I had been using f22-26. This was giving 1-1.5 second exposures and without autobracketing and need to use a remote release with these long exposures, really got tedious. 

 

I’ve been wondering if I’m pushing the f-stop lower than practically needed. Most of my subjects are roughly 1/48 aircraft size and my old photo box 24”, new 32”.

 

At this setup, I tended to be more often near the 55 mm than 18 mm.  Calculating DOF with this arrangement, f8 to f/22 only went from about 0.8” to 2.2”. So regardless, a whole model wasn’t technically in DOF. 

 

Given some of the point and shoot (I.e. without tripod, not lessor cameras) at shows, I can’t help think there’s something else that can bring the shutter times down. 

 

So so what range would you recommend for f-stop?

Link to post
Share on other sites

You didn’t mention your ISO setting, increasing it will shorten exposure times at the expense of image quality.  Try bumping ISO up to 800 then 1600 and compare IQ between exposures. You may find you can go even higher before noise affects IQ. 

 

.

 

Edited by habu2
Link to post
Share on other sites

I would recommend a different lens. I switched from the 18-55 to a fast prime a few years ago. typically I use a sigma 50 1.4.at f/16 I am getting 1/15 sec. shutter  at ISO 100.

 

  you dont need to spend much cash for a good prime. nikon makes a great 50 1.8 that is only about $200. link

 

Link to post
Share on other sites

With that amount of light you shouldnt be having any problems with timing because  of your aperture.

 

Pick the stop up until you are happy with the speed.

 

The higher the aperture the less light is getting to the sensor, make the hole wider and your timing problems will sort themselves out as you will get more light!

Link to post
Share on other sites
 

True, I had been shooting at ISO 100 to preserve as much raw data as possible. But maybe this is also “over the top” and unnecessary. 

Usually you can safely go up to ISO 400 with no adverse effects unless your camera is from stone age.

Edited by Helmsman
Link to post
Share on other sites

Hi there.  I am curious about what your intent is with respect to f stops.  I presume that the reason you are shooting at f22-26 is to try to maximize the depth of field in your images, that is, get more of your models in sharp focus.  If that is your intent, you can keep reading...if those small f stops (i.e. large numbers) are being used for a different reason, I'd like to hear what the reason(s) is/are, as I'd really like to help.  

 

But assuming that depth of field is your intent, I can tell you that for most lenses ( I can't comment on the NIkkor 18-55 lens specifically) begin to distort your image due to diffraction, which will actually reduce the sharpness of your image, which is what you are trying to achieve n the first place, right?  Diffraction begins to occur noticeably once you get into the F20 range or so, the exact f-stop is dependent upon each specific lens.  I would strongly urge you to consider using a more optimum f-stop for your lens, which is most likely somewhere in the f8-f11 range, and use the process known as focus stacking to increase the amount of your model that is in focus in the final image.  In essence, since your subject is a still life and does not move, you can maintain your f-stop at optimum, and take multiple images while changing the focus in each image, which can then be combined to take advantage of the parts of each image that are sharply in focus, and in essence end up with a final image where most, if not all, of the subject, your model, is completely in focus. 

 

Focus stacking for models is nicely explained here: https://doogsmodels.com/2018/10/18/how-to-focus-stack-your-images/

 

Again, though, if your purpose in using small f-stops is for a different reason than wide depth of field, please explain so I can try to help.

Link to post
Share on other sites

 Curt B has a good point. Most lenses have a “sweet spot” around f/8-f/11 wrt DoF vs corner resolution vs diffraction. But we’re really ”splitting pixels” here. I have to say, if your target is posting  pics on the web, most of this is overkill. Megapixel sensors + RAW images + post processing is just Not Worth It for web-based presentations. Half your audience is looking at this on a cellphone .......

Link to post
Share on other sites

Let me begin by saying I'm a novice at picture taking. I have a Nikon DSLR. I shoot at the highest f setting I can. I use a tripod and a lightbox. The images are good enough for magazine printing. While the image stacking is  neat idea, it seems to be labor intensive. I put my images in Photoshop and hit auto color and sharpen and I'm good to go. 

Link to post
Share on other sites

habu and Darren, you both make good points.  For posting here or for posting other places where details are not critical, focus stacking IS a significant amount of work.  If I were to submit my photos to a publication, I’d be inclined to want to make that effort.  But that’s just me.  I use a Canon 5D Mark 4 and have all ‘L’ glass, and I tend to be picky about my images.  That said, though, most of the images I post here are taken with my iPhone 5, far from the cutting edge of even cell phone camera technology, and I find those pictures to be just fine.  And I don’t think I’m an short changing anyone who looks at those photos.   

 

However, I did want to give the OP the benefit of some experience to optimize his ‘higher end’ pictures. 

Link to post
Share on other sites
 

Let me begin by saying I'm a novice at picture taking. I have a Nikon DSLR. I shoot at the highest f setting I can. I use a tripod and a lightbox. The images are good enough for magazine printing. While the image stacking is  neat idea, it seems to be labor intensive. I put my images in Photoshop and hit auto color and sharpen and I'm good to go. 

 

Open up the aperture wider.

The time your shutter needs to stay open will drop as the sensor will see more light and your images will be clearer

Leave the ISO alone at 100, that way you keep all the quality your sensor can muster.

 

As mentioned above all lenses have a "sweet spot" with its f Stop range, there are very few that perform so well with such a small amount of light getting through.

Link to post
Share on other sites
 

Open up the aperture wider.

The time your shutter needs to stay open will drop as the sensor will see more light and your images will be clearer

Leave the ISO alone at 100, that way you keep all the quality your sensor can muster.

 

If you open the aperture, you reduce the depth of field, so how will the images be clearer with a wider aperture? If there is one thing which, in my opinion, make models look like models in a photograph it is a shallow depth of field that cause wingtips and other extremities to be slightly out of focus.

 

You are right that the shutter has to stay open longer for a smaller aperture (everything else being equal), but that you can deal with by using a good steady tripod, a timer or remote trigger, good lighting and increasing the ISO (within reason). With most DSLR's you barely see the difference between ISO ranges of 100 to 400, unlike on traditional film where the difference between ISO 100 and 400 was very noticeable.

Link to post
Share on other sites
 

 

If you open the aperture, you reduce the depth of field, so how will the images be clearer with a wider aperture? If there is one thing which, in my opinion, make models look like models in a photograph it is a shallow depth of field that cause wingtips and other extremities to be slightly out of focus.

 

You are right that the shutter has to stay open longer for a smaller aperture (everything else being equal), but that you can deal with by using a good steady tripod, a timer or remote trigger, good lighting and increasing the ISO (within reason). With most DSLR's you barely see the difference between ISO ranges of 100 to 400, unlike on traditional film where the difference between ISO 100 and 400 was very noticeable.

 

Thanks but erm... I dont need a lesson in photography and how it works.

 

Yes of course opening up the aperture will make the depth of field slightly shallower, however on an 18-55 kit lens it really shouldnt make all that much of a difference. He is flooding the area with 8k lumens of light and he has a shutter speed of 1 to 1.5 seconds!
 

He can do one of two things with the kit he has

Open up the aperture and risk a shorter DoF or raise the ISO giving a slightly fuzzier imagine.

 

Open up the aperture and see the results, if you dont like them then close it all the way down and pick up the ISO but if with 8k lumens of light on a closed lens he isnt seeing enough light then making the sensor a little more sensitive will introduce fuzz, for me bokeh is preferable to fuzz especially as narrowing the DoF might not actually have a negative effect where as raising the ISO possibly will.

 

Its an 18-55mm kit lens remember!

Link to post
Share on other sites

Why not using remote trigger? You can get cheap wireless remotes easily.

I have just got a D850 and was playing with phone app triggering the shutter and it works very well... Not sure though how many Nikon DSLRs have the option, but IIRC some entry level cameras already enable this. I will try focus stacking as D850 has this feature already in the menu, but otherwise so far, I've been using ISO100, F3x something and a little bit of exposure compensation correction and that's it. Check my page vvsmodelling.com galleries to see the results. I'm using 28-300mm lens.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...