Author Topic: Best focal length?  (Read 1723 times)

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diezmon

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Best focal length?
« on: January 09, 2012, 11:26:13 AM »
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Hey dudes,

I've got a Nicon Digital SLR I inherited.. it's got a 70-200mm lens on it and I'm looking to find a lens that's good for model photos. 

If I get a macro, what kind of focus length can I expect?  meaning, it can do closeups.. but can I also capture things further back, in the 1-3' range?  I don't mean in the same shot.. I mean if I use helicon or something and change my focus subject with multiple shots.. if that makes any sense?

what do you guys use?

wcfn100

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Re: Best focal length?
« Reply #1 on: January 09, 2012, 01:09:15 PM »
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I will recommend a stock Nikon 18mm-55mm to start.  I can elaborate when I can get back to a keyboard.

Jason

tom mann

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Re: Best focal length?
« Reply #2 on: January 09, 2012, 09:43:40 PM »
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A 50mm macro lens will allow you to do both.  Unless you want print-quality photos or super up-close photos, a dedicated macro is a little overboard.  You can always use what Jason recommends and crop the photo.

wcfn100

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Re: Best focal length?
« Reply #3 on: January 09, 2012, 10:30:45 PM »
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Okay, a little follow up.

Like Tom said, you can do what you want with a macro in terms of focusing of far away objects.  But doing so pretty much means you have to use some sort of Helicon/CombineZ software where with a regular lens you might be able to cheat the aperture to get DOF.

 The first reason I would go with the 18mm-55mm is cost.  These are the stock lens that comes with most Nikons.  I wouldn't be surprised if you could find one for free.  The second reason is that our brains (at least mine) have been conditioned to 35mm film shots from the 60's and 70's.  To replicate those shots, you need to shoot at 24mm on your digital.  Now it may be tempting to get an 18mm-200mm (I have one), but in my experience, the 18mm-55mm will take better N scale model photos (@24mm).

I rented a 55mm macro a long time ago to play with.



It was fun but a bit awkward.  The shot above was taken from a few inches away due to the focal length.

Here's another of the 105mm macro.



You can see the perspective isn't very realistic.

The Nikkor 60mm is awesome! (but expensive)



IIRC, the photo above was my test of Helicon's automated feature.


Here's what you can do with a 18mm-55mm lens and HF.



I can show more (maybe) if you want anything specific.

Jason

robert3985

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Re: Best focal length?
« Reply #4 on: January 10, 2012, 02:05:01 AM »
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I also use Nikons.  What I will recommend to you depends (somewhat) on what Nikon camera you inherited.  Some Nikon lenses will not work as they were designed on some of the entry level DX cameras such as the D40, D40s etc.

Also, what I'm going to recommend depends on the end-usage of your photos.  Are you going to submit them for publication, or are you just taking them for your own enjoyment and reference and will only view them on your monitor?

Since I've gone digital, I've shot with a Nikon D40, Nikon D300 and now I shoot with a Nikon D7000.  Because my intention is to publish articles for print, my D40 pixel count wasn't big enough for several magazines' minimum pixel requirements.  However, I really enjoyed the camera's small size, which allowed me to get down close to the scenery.  I also really liked its simple wireless remote.  Its file quality was very good also and it got me hooked on digital.

I used the kit lens that came with the camera (Nikon 18-55 f3.5) and got some really good results because of the close focusing capabilities of that little lens, which is also quite good optically.  However, I wasn't happy with the ergonomics of it and soon purchased a Nikon 18-200 f3.5-5.6 super-zoom which overpowered the little D40 body, but allowed me more versatility because of its across-the-focal-length close focus capability.

I soon learned that I needed larger file sizes (more resolution) than the 6MP sensor on the D40 would produce, so I bought a D300 body and sprung for a lightly used AF Micro Nikkor 60mm f2.8 (a true "macro", flat-field optic).

Around this time I also discovered Helicon Focus and bought the pro version.  Suddenly worrying about depth-of-focus was an anachronism.

Because of the DX format sensor in my D300 body, the effective focal length of my 60mm Micro Nikkor was the equivalent of 90mm in a 35mm film camera and took some getting used to.

However, between the 18-200 and the 60mm Micro Nikkor I have been able to compose shots for every situation I've run into so far.  I find myself using the 18-200 at 200mm quite often, close focused and moving my tripod back and forth to get the proper closest focus point.  I also use my 60mm Micro Nikkor quite often, mounting my new D7000 on a sturdy tripod, stopping down to f22 and just exposing a single shot if I don't need a lot of depth of focus.

Remember, the closer you are to your subject the narrower your depth of focus becomes.  I find that very close shots require that I use HF, but moving back a couple of inches greatly increases my depth of focus, and sometimes, I actually WANT my backgrounds to be out of focus.

Although I agree that the cheap (but good) 18-55mm f3.5 kit lens combined with your 70-200 would probably be okay, especially if you buy a set of close-up lens/filters for the lens fronts, if you are serious about your model photography you should look for a used AF Micro Nikkor 60mm f2.8.  I paid $275 for mine, which was a real bargain and it is optically as good as the much more expensive G-model and much sturdier mechanically as well as having an f-stop ring for full manual control, which the new replacement lens does NOT have.

You will also need a remote release (or radio remote release) for your camera body, a sturdy tripod and some 5,000K lights to properly light up your subjects.

Additionally, Photoshop Essentials will go a long way to assist you to manipulate your photos.  Another option would be an older, used version of Photoshop which come up for sale quite often on eBay for practically nothing. Make sure it comes with all the manuals and especially the activation code.  I use Photoshop CS-4 and I don't see any reason to upgrade.

I have other pointers if you need additional assistance, so feel free to ask questions.

Hope this helps.

Bob Gilmore
Modeling the UP in 1951 between Ogden and Wahsatch 
« Last Edit: November 02, 2017, 03:53:22 AM by robert3985 »

DKS

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Re: Best focal length?
« Reply #5 on: January 10, 2012, 09:38:43 AM »
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I've found a set of extension tubes to provide an adequate macro lens substitute. This also allows you to use your choice of lens for the shot.

I've posted a couple of articles online about my experiences, here and here.

diezmon

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Re: Best focal length?
« Reply #6 on: January 10, 2012, 11:43:18 AM »
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As for use, I'd like to have something for publishing work, as well as decent web shots on the forums, etc... 

I'd been working on modifying a kato truss bridge, and thought I'd write it up. So I took pics with my little one shot digital, which turned out looking OK, but not great.  I need better control over focus and lighting for closeups.



Take, for example Bill's article on the Hiawatha work.  I'd like to take photos of rolling stock like that.   I'm not so worried about depth of field in a single shot, since I'd like to learn how to use helicon.   That said though, the smallest f possible would be good. 

Thanks for all the info guys.  I think what I'll have to do is take it into National Camera and try a couple out. 

Oh, and I didn't mention.. I ain't got no money  ;)
« Last Edit: January 10, 2012, 11:45:30 AM by diezmon »

DKS

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Re: Best focal length?
« Reply #7 on: January 10, 2012, 02:07:15 PM »
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Oh, and I didn't mention.. I ain't got no money  ;)

Two options... Try CombineZ--it's free. Or, you can send me the images, and I'll do the stacking with Helicon.

wcfn100

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Re: Best focal length?
« Reply #8 on: January 10, 2012, 02:14:44 PM »
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HF should have a free trial but CZ works very well. In fact I think the last shot I posted might have been CZ and not HF.

Jason

Smike

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Re: Best focal length?
« Reply #9 on: January 10, 2012, 05:57:12 PM »
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Also something to keep in mind is that most DX format cameras will max out on sharpness (via diffraction) beyond F11 or F13 with a lens. If you go beyond that you may get more in focus (DOF) but overall sharpness will start to suffer. Not a problem on a 12mp image downsized to display on the web, but may work against you in full res magazine comp.  You can always test and shoot a range of shots adjusting F stop to see, then zoommed in on screen to 100%. 

Of course all this could be just taking this way too seriously :facepalm:

NS-CRE

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Re: Best focal length?
« Reply #10 on: January 10, 2012, 09:43:31 PM »
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I use a Nikon D90 (previously used a D70) with an 18-55 lense.  I use the self timer and set the exposure length long with the highest possible f-stop.  I do not use Helicon or any other similar software.  I just set the camera up on a tripod, compose the scene, hit the button to start the timer (since I don't have a remote) and stand back and wait for the image to be shot.

Depending on the lighting, exposures may be one to four seconds or longer.  The high f-stop results in good depth-of-field.
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ednadolski

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Re: Best focal length?
« Reply #11 on: January 10, 2012, 11:08:26 PM »
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robert3985

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Re: Best focal length?
« Reply #12 on: January 11, 2012, 03:33:40 AM »
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Well, if ya "ain't got no money" then pick up a used Nikon 18-55 f3.5 (they're all over the place) and some screw-on close up lenses.  That's about as cheap as you'll be able to go.  You'll be able to use the screw-on-close-up lenses on both your 18-55 and 70-200 if you have the 70-200 I'm thinking you have (I had this combination on my D40 and it was an optically excellent kit).  BUT, ya still need a tripod if you're going to use HF (or equivalent), but it doesn't have to be fancy...just sturdy.  Used ones that are pretty beat up but good mechanically are all over eBay.  Manfrotto or Bogen make good, not-too-expensive ones and you might be able to get one for really cheap that will work just fine for you, but be ugly.

Your D90 has an excellent 12MP DX sensor which in tests is actually a little better than the same sensor in the pro D300s.

As to high f-stops and diffraction.  I won the 1992 MR photo contest with my Nikon N8008 with a Micro Nikkor 60mm f2.8 stopped down to f32 on Fujichrome Velvia transparency film.  Evidently any diffraction that might have degraded the image wasn't noticeable enough to make an iota of difference in the photo reproduced in the centerfold of the magazine that year.  I suppose if I had taken a photo of a brick wall then it might have been noticeable, or maybe it IS noticeable but nobody's looking for it. 

When you send in your photos to illustrate your articles, the photo editor is going to look at your file size, your composition, your white balance, your sharpness and your depth of focus, but NOT if there is diffraction from stopping down to f32.

However, it is probably good to know that excessively small f-stops result in diffraction (on both DX and FX sensors), but it's not something that should take precedence over getting your maximum depth of field, especially if you don't want to use software to extend your DOF.

Hope this helps.

Bob Gilmore
Modeling the UP in 1951 between Ogden and Wahsatch


« Last Edit: November 02, 2017, 03:55:12 AM by robert3985 »

Smike

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Re: Best focal length?
« Reply #13 on: January 11, 2012, 12:30:18 PM »
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Full size (at least in 35mm terms) doesn't show the diffraction as much as say on a cropped DX sensor. (It something to do with physics, but I only know enough to be dangerous)  I do agree, most times it’s a moot point to worry about. Although resolution can become an issue with an image is that is heavily cropped. The more cropping the closer one get to see the limits of image resolution.

I LOVED Velvia (miss it dearly as I don’t shoot film anymore) What I do find is 12mp from any modern DSLR will out resolve Velvia. But that warm tone saturated goodness that came out of the box with Velvia was magic that any diffraction would not have mattered.   You hit it right on with Exposure, composition, White balance , and file size are really what matters. 

That Nikon Micro 60mm is insanely sharp, one of my long time favorites in my bag.

Do you have a link to the photo? I love good eye candy, and  highly awarded eye candy is even better!!  :D

robert3985

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Re: Best focal length?
« Reply #14 on: January 19, 2012, 01:46:39 PM »
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Model Railroader owns the copyright to the photo now, but I have one that is identical to it except I included some Hallmark CA-1 cabooses on the westbound track.  I'll post it in a couple of days. 

If you have old MR's, you can see it in the March 1992 issue, and in the "Art of Model Railroading" 1994 (month of March) calendar.

Bob Gilmore
« Last Edit: November 02, 2017, 03:56:49 AM by robert3985 »