This is *not* a zoom vs. prime thread! :)

This is a sincere question from an old film guy newly into digital and a whole new world of post processing.

In film days, a zoom might have been needed to properly frame an image. I say 'might' only because it wasn't as easy as jumping on your laptop and cropping in photoshop.

Couldn't a case be made that zooms are not as critical anymore since pp cropping can eliminate the need for 'infinite' focal lengths? Before you answer, I *do* understand that cropping an image will result in lower IQ the more you have to increase the image size vs. one that isn't cropped. My question is one within reason: say having available 24mm and 50mm primes vs. a 24-70mm zoom, for example.

Also, with the IQ of digital seemingly headed to the moon, won't it be even more of the case as time marches on? (that being the ability to retain high IQ's on even a more-than-moderately cropped image)

I also understand that events such as sports or wildlife photography you may have no clue how far away something may present itself. For grins, let's keep that out of the discussion as well and try to keep it focused on the ease of pp cropping vs. putting the focal length right where you want it in the field.

I'm just beginning my glass collection and this has me wondering out loud as I move forward.

Thanks for your insights.

I have a tendency to shoot a little wide and crop in PP. The main reason I like my zooms is the flexibility if i'm just out taking pictures of things and not really sure how far away they're going to be.

Otherwise, yeah, a handful of primes (35,50,85) would probably serve you just fine in any controlled situation.

Think about the DOF to in your scenario. If you're going with a shallow DOF then standing further back and croping will negate it. But if that's not what you're going for then I think your logic is sound.

I agree with your insights to the advancement of digital photography. Conversly, the same arguement can be made regarding zoom lenses. The IQ which are now produced on your better zoom lenses is nearly as good as your best primes, and maybe more if your factoring in loss of quality from cropping. The one area which primes are still king (for now anyway) is they are faster. So, if you can live with a 2.8 max., why not give yourself the focal range flexibility?

justaf IREMAN wrote in post #9576655
Think about the DOF to in your scenario. If you're going with a shallow DOF then standing further back and croping will negate it. But if that's not what you're going for then I think your logic is sound.

Good point. I didn't think of this. Although having wider aperture possibilities with primes gives you more DOF flexibility as well, right?

J-Blake wrote in post #9576722
I agree with your insights to the advancement of digital photography. Conversly, the same arguement can be made regarding zoom lenses. The IQ which are now produced on your better zoom lenses is nearly as good as your best primes, and maybe more if your factoring in loss of quality from cropping. The one area which primes are still king (for now anyway) is they are faster. So, if you can live with a 2.8 max., why not give yourself the focal range flexibility?

My main gripe is bulk. I'm wondering if I'd rather have another fast prime on my hip rather than a heavy lens in my hands at all times.

Depending on your subject a zoom can add significant versatility than a prime. Shooting a wedding let's say I frame the bride & groom with a 70-200 at the wide end, then I see the bride tear up, I can isolate her expression zooming in without moving, and remaining a non-distraction. Same can be applied to shooting widlife. A close-up of the subject then zoom out to capture it in more of its environment without moving and potentially scaring it off.

dog rocket wrote in post #9576536
This is a sincere question from an old film guy newly into digital and a whole new world of post processing.

In film days, a zoom might have been needed to properly frame an image. I say 'might' only because it wasn't as easy as jumping on your laptop and cropping in photoshop.

This is a simplified answer that I'm sure many people will disagree with or pick apart.

It still isn't, unless your primary interest/purpose is relatively small resolution images

No. Play with zooms some more, and read up on perspective vs focal length. Using a zoom lens gives you an entire degree more of freedom for choosing a perspective (which is based upon your distance from subject) and framing (which is tied to focal length). There are simply some shots you cannot get with a prime if the focal length is too long, and other shots that will come out horribly if the focal length is too short (sensor size, pitch and diffraction limits come into play).

IQ is not headed to the moon. Today's SLR cameras are already diffraction limited at certain apertures. Assuming perfect lenses, IQ in your camera is limited by the physical size and layout of the sensor. In some cases, the only way to eke out higher IQ is to ascend to MF or LF photography.

I also understand that events such as sports or wildlife photography you may have no clue how far away something may present itself. For grins, let's keep that out of the discussion as well and try to keep it focused on the ease of pp cropping vs. putting the focal length right where you want it in the field.

I'm just beginning my glass collection and this has me wondering out loud as I move forward.

Thanks for your insights.

I use the following guidelines:
I shoot with primes if I need the (shutter) speed, want the best IQ, or need to travel light.

I use zooms for more control over framing, events where the 'action' is spontaneous and I don't know how far I will be from it, or if I have a safe place to stash (and switch) lenses at will.

My 17-50 f/2.8 is my most used lens

Tarzanman's response is exactly what I was thinking but he explained it better than I could. The only thing I might add is that primes often have an advantage of shallow depth of field because of their apertures. That's a big plus for me.

dog rocket wrote in post #9576805
My main gripe is bulk. I'm wondering if I'd rather have another fast prime on my hip rather than a heavy lens in my hands at all times.

if you are comparing L primes to L zooms you'll find that the 35L is about the the same size and weight as the 17-40L and the 24-70L about the same as the 85L.

heck i thought i was saving weight by using zooms .

ed rader

ed rader wrote in post #9577255
if you are comparing L primes to L zooms you'll find that the 35L is about the the same size and weight as the 17-40L and the 24-70L about the same as the 85L.

heck i thought i was saving weight by using zooms .

ed rader

OF course, if you go for the most extreme examples. Compare a 28mm f1.8 and 85mm f1.8 instead. Both are significantly smaller and lighter as well as being much faster.

Tarzanman: yes, perspectives is a good point. Another point I hadn't considered. Although, hopefully it's more of 'boning up' than 'reading up' as I'm not new to photography as a science. Lens perspectives hasn't changed much in the past 30 years has it?

My point was probably much too much simplified as you pointed out. As I pointed out, digital photography is all new to me so I'm digesting what I can. I'm also real rusty in some of my old learnings... hopefully they are still stashed in my little head somewhere.

Regarding my 'to the moon' comment: I clarify it to say from someone sitting on the fence watching it from afar... it seems to me that since the 90's digital technology has been to the moon and back! lol. Especially when compared to film. Wouldn't you agree?

ed rader wrote in post #9577255
if you are comparing L primes to L zooms you'll find that the 35L is about the the same size and weight as the 17-40L and the 24-70L about the same as the 85L.

heck i thought i was saving weight by using zooms .

ed rader

Wow... now this I didn't know. (I could never afford the real good stuff in the old days) How about that...

When I was studying photography I was taught to really fill the frame with the subject. Get everything you want onto the exposure, and nothing extraneous. It was so important to my lecturer that he was totally disdainful of the guys that had to constantly crop.

It was really good advice, and I've helped out hundreds of happy-snap togs with a 3 minute photography lesson based primarily on that advice.

My first significant shoot with my new digital was at a gator park. Lots of action shots of huge lizards leaping out of water to get food. Leaping out of the frame too, cause they move sooooo flamin' fast! Had I pulled back just a little, I'd have gotten a *lot* more keepers.

With the 5dII you have a lot of room to crop with before you lose detaili, IQ and the ability to print reasonably large.

The interesting thing about this thread is that I'm hesitant about digital because of the pp and not really looking forward to that part of it. I would rather get the shot I want straight from the camera. OTOH, I was just wondering how far you could/should take it and how that might affect my gear selection, is all.

Maybe I should have asked this question instead:
Has digital photography PP affected your lens purchases?