[FtYoU]

Hi everyone !
I have a general zoom vs prime question now that Pentax has a trinity lineup. First of all I am pretty new to Pentax and own a K-1. Before Pentax I was used to shoot primes. Seing the new zooms of pentax (10-30, 24-70, 70-200) packed with all the good stuff of WR, coating etc I am wondering if getting a zoom (the 24-70 for example) would be beneficial compared to owning 2 primes lens. Right now I have the Sigma 35mm f1.4, and I am planning to complete it with a telephoto lens (probably the 85mm f1.4). it bother me a lot to have to change primes every-time I need a different focal. Moreover I like the fact that a zoom will stays on the camera and is WR... I do not shoot studio, most of my shooting is astro/landscape/street. So here is my questions and concerns :

1) is the image quality of the primes that much superior of this zoom ? I am planning to print some of my work.
2) Will I be really impacted by the bookeh coming from f1.4 to f2.8 ? or this is just a slight change at those wide apertures ?
3) Personal experiences from switching ?

Remarks and questions are welcome.
Thank you guys !

[BigDave]

Ft:
Having similar lenses I will say that the one thing the zooms will provide is convenience. Less switching from one lens to another. But the primes with the wide apertures will provide some nice BG blurr (bokeh) that the zooms may not be able to provide. And yes, there is a difference between f1.4 and 2.8 in the BG.

Regards,

[jimr-pdx]

Until Pentax puts weather seals on some more primes, the zooms are sadly the only way to protect the system to the max. Even if that starts happening it will be a while, so my thinking is that a good mix of zooms and special primes is the best choice for now.

[clackers]

I love my primes, but most of the pro work you see is shot with a zoom. ☺

[jatrax]

In the old days there was a clear difference between primes and zooms. These days, not so much. A good modern zoom, like the DFA 24-70 will produce excellent images that mostly cannot be distinguished from images taken with a prime at the same aperture.

However, this forum is heavily prime centric and a lot of people will try to convince you that primes are the way to go. They do have some advantages, first light weight compared to a big f/2.8 zoom. And they can have faster apertures, though they don't always.

So:
1) The image quality difference is IMHO, mostly smoke and mirrors. The exception being some of the Limited lenses that provide special rendering, and lenses with fast apertures
2) I don't think so, but that is subjective and others will have a different opinion. Does anyone really shoot at f/1.4 anyway?
3) I had a full set of DA Limited primes but found I almost always reached for a zoom instead. Not that they were not nice lenses and fun to shoot with, I just found the zoom to be easier and just as good. I sold them off and bought the DFA 24-70. So far very happy. But I keep watching the market for FA limited's. LBA is a slippery slope...............

[othar]

1) zooms are always a compromise so IQ (especially in the corners) will usually be better with primes, but the difference in IQ will commonly vanish or at least lessen when stopping down. -> for landscape pictures I mainly use f8 - f11 (sometimes f16 or higher if I need the DOF) where the difference is no longer that tremendous so a zoom is a convenient alternative. Depending on how strong you are playing with DOF a zoom also will be perfectly suitable for street photography, but at astrophotography I think you are better off with faster primes (although I have seen some good startrail pictures taken with zoom lenses too). I neither have a K-1 yet nor any of the lenses you mentioned so I can't give a founded opinion on those.

2) DOF and therewith bokeh also depends on focal length and focusing distance, but I am not an expert in this field. Another thing to consider with f1.4 and f2.8 is correct focus wide open, I just have two fast primes and those are manual focus only so I don't know how well AF works at f1.4 but nailing the focus on moving subjects wide open is nearly impossible for me, therefore I mainly photograph still or slow moving subjects and use a tribot + LV when shooting wide open.

3)When I am hiking/mountaineering I generally have my Pentax-F 35-70mm lens mounted on my camera (the K-3 so aps-c sensor size) which is handily placed in a small bag outside of my backpack. I carry a small collection of my other lenses inside my backpack. [my DA-L 18-55mm kit lens (if I need a wider lens or if there is bad wheather because this is my only WR lens), my A 50mm f1.7 (so small it goes nearly everywhere with me) and a telezoom in case there is some interesting wildlife around]
Apart from some rare occasions where I wouldn't be able to get the picture otherwise I hardly ever switch lenses during my trips. Although a zoom lens is more convenient this behavior not just applys to my F 35-70mm lens, this is true no matter if zoom or prime lens.
Once I gave my cousin a analog camera of mine mounted with the F 35-70mm lens and I used my K-3 with the A 50mm prime lens during an 8h trip. I only switched lenses once because i needed more reach, but except from that I either zoomed with my feet or I made overlapping images for stitching, which turned out great btw .

Regards Patrick

edit:
I misunderstood your third question, but I don't have much to say about switching from primes to zooms anyway, because I use both alternating. One thing maybe, when I was using a zoom lens with a range from wide angle to short telephoto for the first time (like the 18-55mm on aps-c) I became a little lazy regarding zooming with my feet and ended up with some portraits shot with a wide angle focal lenght what is often not a good idea if you are not going after a certain look.

[mikeSF]

i shoot with both but definitely favor a good prime over a good zoom for better contrast and stray light handling.

If you use auto-focus, consider that with every prime lens, you could be dealing with variations in focus accuracy depending on where in the distance range your subject is. That is, at close range, AF could be just right, then shift slightly out as you focus more distant objects.
With a zoom, you now must consider the chance that the same will occur for near vs far objects, AND could vary by focal length as well. I am not saying it is impossible to find a copy of a particular lens that is dialed in reasonably well, but I am saying there are plenty of copies that won't do it right. Many folks just put up with having a zoom that is inaccurate at one end of the range, etc, instead of sending back copies until an acceptable one is received.
Food for thought.

[UncleVanya]

I didn't think the question was about zoom or prime but what primes. But here's my 2 cents worth. A great interview was out there on the internet that I can't find right this moment. It was with a Zeiss engineer and he basically said, Zooms can equal or exceed primes often. The reason being that so much more correction can go into a complex zoom and the primes are most often optimized for size and weight rather than performance alone. Many zooms are more about performance than any other characteristic. This was of course directed at high end zooms not consumer zooms.

My contention from my own observations is that the benefit to a prime - really - is the ability to focus on the shot a little differently. Having fewer factors to distract from your effort can be useful depending on how you think. Beyond that I have no particular concerns about zooms. The 17-70 my dad has is lovely at both ends and in between. The DA* 50-135 and 60-250 are both excellent at any focal length they cover. The FA 31 and FA 77 I have are fun special lenses - with faster f/stops than the zooms which is one of the reasons I sometimes prefer them. The other issue is that my father took most of my zooms for himself! LOL So I developed a habit of using Primes again after being a zoom guy. Frankly there is nothing wrong with either approach - no one is going to spit on your pictures and say - bah - that was a zoom shot.

[Eyewanders]

Add one of the zooms to your kit. Try it. That's my initally unhelpful advice.


1) is the image quality of the primes that much superior of this zoom ? I am planning to print some of my work.

Often, yes, but many high quality zooms are nothing to scoff at. The DA*50-135 renders astoundingly well as many know.

2) Will I be really impacted by the bookeh coming from f1.4 to f2.8 ? or this is just a slight change at those wide apertures ?

Depends on what/how you shoot and whether you often need that extra DOF - and yes, it significant amount, but it really depends.

3) Personal experiences from switching ?

I've never switched - I go back and forth, but over time I've sold all my zooms but for 2 - the (aformentioned) DA*50-135/2.8 and an amazing late-model Vivitar Series-1 70-210/3.5 which I adore. You don't need to switch. Pick a lens that best suits your task and kick some posterior.

[One3rdEV]

I really, really, like the contributions (with specific clarification details) that those who responded before me gave regarding the prime vs zoom debate. This helps to reaffirm my appreciation for many of the great people who can be found among this forum.

It is quite common on the web to encounter endless echoes from the past that in modern times are often equivalent to myths. But based on my experience the above statements are quite sound.

[FtYoU]

I really, really, like the contributions (with specific clarification details) that those who responded before me gave regarding the prime vs zoom debate. This helps to reaffirm my appreciation for many of the great people who can be found among this forum. It is quite common on the web to encounter endless echoes from the past that in modern times are often equivalent to myths. But based on my experience the above statements are quite sound.

Yes ! I would like to take a moment to thank everyone here, really it is really nice to see how helpful and subjective but not arrogant answers I got here. Pretty stoned.
I took the DFA 24-70mm f2.8 to test and I will decide. The WR, all around lens, coating are a big plus for my kind of shooting. Let's see if I really need the extra DOF.

[bassek]

The most difficult thing to get used to is the extra weight.

Seb

[FtYoU]

The most difficult thing to get used to is the extra weight.

Atually the Sigma 35mm f1.4 is pretty heavy already .... I do not mind it though

[Kerrowdown]

For me shooting manual focus, a big bright viewfinder is essential, so it's fast primes for me, but I'm unusual and perhaps not that common with that requirement.

[bassek]

Atually the Sigma 35mm f1.4 is pretty heavy already .... I do not mind it though

My heaviest lens is a prime, the Sigma EX180 macro. All my 3 Sigmas are bulky.

Seb