Zooms or primes

[ErikKaffehr]

Hi,

I would suggest that are basically two different approaches. One is to use a small set of focal lengths that you know well. Than you choose perspective and crop to suit a lens you have. The other approach is that you select perspective and crop and find the matching focal length. Both approaches are workable, indeed, when I shot both 135 and MF on film I used zooms on 135 and fixed focals on MF. So I could shoot something on one day with zooms and 135 and with primes and 120 another day.

Best regards
Erik

Dave, I find you comment fascinating, since it's the opposite for me.  As I said in an earlier post, because my ability to position myself ideally is usually constrained, I shoot with a zoom (although within a pretty small range centered around my preferred focal length).  When I switched to the D800E I shot only with a 35mm prime for a while - the only lens I had at the time - and I found that using it I was getting "compositionally lazy" as you put it.  Since the ways I could frame the shot I saw were limited in terms of positioning, it was "get it more or less and fix in post" so I ended up not working as hard on the composition in the field because my choices were constrained.  Whereas with the zoom (which I am back to using having acquired one) since I can nail the composition in camera I am forced to think about what it really is in the scene that caught my eye and what I have to do compositionally to convey that.  So for me, paradoxically, the zoom makes me a better photographer.  Just goes to show . . .  

(That said, my advice to beginners who want to develop their eye is to use a single prime to avoid the trap of being scattershop with a zoom.)

[Ray]

I must admit that I'm not sold on this idea that making things difficult for oneself and throwing technological hurdles in the way by limiting oneself to the use of a fixed focal length, results in better photos as a general rule. But I can see there will sometimes be instances when a better photo might result from the use of a prime, if for no other reason than the different perspective resulting because one was motivated to get either closer or further away from the subject than one would if a zoom were attached to the camera.

In this sense, perhas the fixed prime lens also has a health benefit because it motivates one to walk more and get more exrecise. This could be used as an advertising slogan. "Want to lose weight? Buy a prime lens." 

[marcmccalmont]

I'm biased towards high quality zooms and always thought that cropping the next widest prime lens to capture your subject would negate the resolution advantage the prime lens might have.
If you can't move closer, which is often the case, the resolution of your sensor is utilized better with a lens zoomed in, this usually is not discussed in these debates.
Marc

[Ray]

I'm biased towards high quality zooms and always thought that cropping the next widest prime lens to capture your subject would negate the resolution advantage the prime lens might have.
If you can't move closer, which is often the case, the resolution of your sensor is utilized better with a lens zoomed in, this usually is not discussed in these debates.
Marc

Hi Marc,
There are lots of comparisons that can be made at Photozone, comparing the resolution of prime lenses with zooms of a longer focal length.  Dividing the longer focal length of any particular zoom by the shorter focal length of a particular prime gives one the effective crop factor, which in turn allows one to calculate the resulting resolution of the image from the prime lens that has been cropped to the same FoV as the image from the longer focal length

I have only a couple of Nikkor lenses, both zooms. I've recently ordered the AF-S 85/1.8G because it seems remarkably sharp and good value. It's certainly much sharper at F4 than my Nikkor 24-120/F4 is at 85mm and F4, according to Photozone's tests on the D3X. It's also sharper at F8, but to a lesser degree.

Out of curiosity I wondered how it would compare with the 24-120 at its weakest focal length of 120mm, shooting from the same position with both lenses.
The crop factor is 120/85 = 1.4. The centre resolution of the 85mm prime at F8 is 3693 LW/PH. Dividing that figure by 1.4 gives us a resolution of 2638 LW/PH.
Now, according to Photozone, the resolution of the Nikkor 24-120 at 120mm and F8 is 3385 LW/PH. I'm quite sure there would be a very noticeable difference in practice between these two resolutions of 2638 and 3385.

In other words, if I happen to have the Nikkor 85/1.8G attached to my camera but need a 120mm focal length because I can't move closer, for whatever reason, I should get noticeably better results in the centre of the image by switching lenses and using the 24-120 zoom at 120mm.

However, the borders are another matter. If one crops the image from the prime lens, then the Photozone results for the borders and extreme borders don't apply. The figures will be higher because the borders will be closer to the centre. It looks as though in this example, comparing an excellent prime with a medium quality zoom of longer focal length, the prime might still retain equal or even better sharpness at the borders.

When the lenses are compared at F4, 85mm cropped to the 120mm FoV, it appears that the 85mm prime should actually still be sharper at the borders, though still not quite as sharp in the centre, ie, 2766 for the cropped image compared to 3025 for the zoom at 120mm.

When I receive my 85/1.8G prime, I might try to confirm this with some tests, just to get a handle on the practical significance of any differences.

Cheers!

[Fine_Art]

As an old pro Ray, I think you know that if you need a 120mm perspective you will use a 135 prime instead of the 24-120 zoom. Or stitch 4 200mm prime shots. You will use your 85G where you used to use your zoom at normal. etc. Primes are generally small and light so taking a range of 4-5 is not a big deal. Please post your shots, you will make the lens look good.

[ErikKaffehr]

Hi Marc,

As far I know you are also shooting MFD on a technical camera. In film days I was shooting zooms on 135 and primes on Pentax 67. I could live with both. I guess it is a different mode of operation, or a different mindset.

I have a number of primes and a number of zooms, but I basically shoot medium apertures using tripod, when I can, and essentially never shoot wide open on the primes I have. So the primes go pretty much unused, unless they have anything special to offer.

Best regards
Erik

I'm biased towards high quality zooms and always thought that cropping the next widest prime lens to capture your subject would negate the resolution advantage the prime lens might have.
If you can't move closer, which is often the case, the resolution of your sensor is utilized better with a lens zoomed in, this usually is not discussed in these debates.
Marc

[Ray]

As an old pro Ray, I think you know that if you need a 120mm perspective you will use a 135 prime instead of the 24-120 zoom. Or stitch 4 200mm prime shots. You will use your 85G where you used to use your zoom at normal. etc. Primes are generally small and light so taking a range of 4-5 is not a big deal. Please post your shots, you will make the lens look good.

Well, first of all, Fine_Art, I don't like changing lenses in the field. I've dropped a lens only once in my life, and that was when changing the Sigma 15-30 zoom, when attached to my 5D, for a 50mm prime. The bulky zoom fell on the forest floor and rolled down the hill for a few metres.

Another issue is, I don't like using tripods, unless I have to, for a night shot, or to blur a waterfall for example, therefore I rely a lot upon image stabilisation or VR.
If the lighting is such that I need a 1/125th sec exposure at F8 and ISO 400 with my 24-120 zoom at 100mm, attached to my D800E, I'm not sure there would be much point in changing to the 85/1.8 G which, without VR, would require a 500th exposure at ISO 1600, assuming I want an F8 DoF. The couple of stops worse SNR and DR would tend to negate any resolution advantage.

[Fine_Art]

I see. I think it was you that posted some Angkor Wat images a few years back. I figured you were the slow meticulous MLU with cable release type.

[Ray]

I see. I think it was you that posted some Angkor Wat images a few years back. I figured you were the slow meticulous MLU with cable release type.

I can be slow and meticulous, and with a bag-full of prime lenses instead of a couple of zooms, I guess I would have to be.

It so happens that Angkor Wat can be a very frustrating place for the slow and meticulous. You see an interesting scene, but find that your lens is unnecessarily wide. By the time you've changed it to something more suitable, and have positioned yourself in the best spot to get the most pleasing composition, a bus-load of tourists arrives on the scene and remains there till every member of the group has had a mug shot whilst obscuring a most wonderful piece of ancient sculpture that many of us have paid thousands of dollars and travelled thousands of kilometres to see.

However, there is at least one occasion when even the most vain and narcissistic appear content to view the naked scene without an image of the themselves superimposed upon it, and that's the scene of the sun rising behind the temple of Angkor Wat.

However, even in the following shots, only the first one required a tripod for the slow shutter speed of 1/4th second. No. 2 at 1/100th and 28mm would have been okay without a tripod, and the third was nowhere near requiring a tripod.

[BernardLanguillier]

Very nice images!

The one below was shot with a prime...  



Cheers,
Bernard

[Ray]

You've captured the light well, Bernard. But weren't you a bit regretful when cropping away some of those expensive Mamiya ZD pixels? 

The fact that stitching programs have improved so greatly in recent years really does offer a way to reduce the resolution disadvantage of zoom lenses in many situations.

I'm susrprised that in Photoshop's Photomerge it's now quite rare that a stitch of a few hand-held shots will not stitch seamlessly. On my last trip to Siem Reap, carrying just two zoom lenses, I would frequently use a longer focal length to take 2 or 3 or 4 shots for stitching, even when standing just a couple of metres away from a bas-relief.

Whilst the resulting image will likely not be as sharp at 100% view as the same scene stitched from shots taken with a prime lens of the same focal length, one would never notice the difference on a print smaller than, say, 4 metres by 3 metres, or even 3mx2m, which is probably much larger than one would ever want to print.

For the following 621 MB stitch (16 bit) I set my zoom lens to 40mm instead of taking a single shot at 24mm. A 33% view on my HD monitor represents a print size of about 900mm x 1 metre, bigger than my 600mm wide printer can handle, without creating a diptych. The 100% view on the monitor, which would reveal the extra detail one would expect from a good prime lens, is representative of a print of about 10ft wide by 8ft 6" high, which is slightly taller than the walls in my house.

Mind you, I suppose I could crop it just a bit more in order to fit it between the floor and the ceiling, but since I don't have my partner or companion on the far bank jumping up in the air or trying to be amusing in some way, it doesn't really pass the narcissism test. 

[BernardLanguillier]

You've captured the light well, Bernard. But weren't you a bit regretful when cropping away some of those expensive Mamiya ZD pixels? 

The fact that stitching programs have improved so greatly in recent years really does offer a way to reduce the resolution disadvantage of zoom lenses in many situations.

Yep, I am totally sold on stitching, believe me. 

I also did stitch with the ZD, but for some reason not that much in Angkor.

Cheers,
Bernard

[Fine_Art]

Stitching removes the disadvantage of 135 format in general compared to medium format.

Very nice images BTW.

[Petrus]

Stitching removes the disadvantage of 135 format in general compared to medium format.

Very nice images BTW.

Then, MF files can be stitched, too...

I have to debrief some of you guys before October, as we (wife & me) are planning a Nepal-Laos-Cambodia trip at that time. Couple of days in Angkor Wat, naturally. Looks like early wakeups...

[Ray]

Yep, I am totally sold on stitching, believe me. 

I also did stitch with the ZD, but for some reason not that much in Angkor.

Cheers,
Bernard

In that case, Bernard, you should have no problems using a zoom in preference to a bunch of primes. In circumstances where you would take a single shot with a prime, just take two with a zoom at a slightly longer focal length. In circumstances where you want a really high resolution image and would take two or more shots with a prime lens for stitching purposes, take three or more shots with the lower quality zoom.

It's also much quicker to adjust the focal length on a zoom than it is to change lenses. When I came across the above scene at the Bayon, those swans might have flown away whilst I was stuffing around changing lenses.

[Ray]

Stitching removes the disadvantage of 135 format in general compared to medium format.

Very nice images BTW.

Thanks. Yes, it does, provided the scene is reasonably static. I guess a model would have to remain unusually still in order for two shots of her face to be successfully stitched. 

[Ray]

Then, MF files can be stitched, too...

I have to debrief some of you guys before October, as we (wife & me) are planning a Nepal-Laos-Cambodia trip at that time. Couple of days in Angkor Wat, naturally. Looks like early wakeups...

That's true, but if you can easily make a stitched image with 135 format that's large enough to fill an entire wall from floor to ceiling, do you really need to stitch MF files to make an even bigger print? 

Best of luck with your planned trip to Nepal and Cambodia.

Cheers!

[BernardLanguillier]

That's true, but if you can easily make a stitched image with 135 format that's large enough to fill an entire wall from floor to ceiling, do you really need to stitch MF files to make an even bigger print? 

If you stitch then there is very little value using MF compared to, say, a D800.

In fact there are mostly advantages in favor of the DSLR.

Cheers,
Bernard

[Ray]

If you stitch then there is very little value using MF compared to, say, a D800.

In fact there are mostly advantages in favor of the DSLR.

Cheers,
Bernard

Yes, I'd agree absolutely. The following image is a 333MB stitch of just two frames taken with my D800E and mediocre Nikkor 24-120 zoom set at 50mm, hand-held. No problems at all with the stitching in PS6.

If I were to make a print of this image, about 1 metre by 1 metre, what people would see from a close-up inspection of the detail, would be the same as a 50% enlargement of the image on a 24" HD monitor. At this degree of enlargement, every grain of sand on the surface of the sandstone appears to be clearly discernible.

Cheers!

[BernardLanguillier]

At this degree of enlargement, every grain of sand on the surface of the sandstone appears to be clearly discernible.

The D4x + stitching will probably enable us to see at molecular level. Crystallographic analysis on screen should become a breeze...

Cheers,
Bernard