[aslyfox]

Awesome advice!!

Can anyone tell me what a "prime" lense is? I have been poking around this website after work the last couple nights...there is a lot of good info here. . .While I do not have an unlimited budget, we like to buy quality stuff that will last. .

Pentax does that IMHO

short answer prime vs. zoom:

one has a fixed focal length, the other offers variable focal lengths

" prime " lenses


Pentax DA Prime Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

are not " zoom " lenses

Pentax DA Zoom Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

back in the days of film, a lot of zooms were disfavored by some because the ability of the zoom made it not as good as a prime

" Jack of all trades, Master of none " type of idea

not so true now a days for the best zooms

___________________

lots of good info and help in the articles

these articles might be worth reviewing

https://www.pentaxforums.com/articles/photo-articles/lens-terms-and-abbreviations.html

https://www.pentaxforums.com/articles/photo-articles/photography-terms-cheatsheet.html

https://www.pentaxforums.com/articles/gear-guides/top-pentax-gear-of-2018.html

https://www.pentaxforums.com/articles/gear-guides/recommended-pentax-gear-2016.html

The Crop Factor Unmasked
Field of View vs Focal Length on various formats


Read more at: https://www.pentaxforums.com/articles/photo-articles/table-of-equivalent-foc...#ixzz5g0ROoWvD


________________________________________________

https://digital-photography-school.com/full-frame-sensor-vs-crop-sensor-which-is-right-for-you/

---

Last edited by aslyfox; 02-19-2019 at 12:18 PM.

[david94903]

The 18-135mm will offer better durability, more versatility (with the added reach), and slightly better image quality, so it would be my recommendation.

I concur, the 18-135 is a very good lens and would be the better of the two choices

my first thought would be to recommend the DA 15mm Limited.

DA15mm, absolutely the best wide angle prime for the APS-C sensor, IMHO.


My wife has this kit on her K-30 - DA18-135 is her primary walk around lens, it's light and versatile; the DA15mm, for landscapes and just fun wide angle work; and the DA55-300 for longer reach. She also has an FA100mm f/2.8 macro from "the old days", which she loves for portrait work.

[Fenwoodian]

.
The favorite feature on my K70 is "Pixel Shift".

If you decide to purchase the K70, and after you've had it a few weeks and read the operating manual, try your K70 in the Pixel Shift mode. For Landscape photos on a tripod of stuff that doesn't move K70 Pixel Shift image files will blow you away!

[Hattifnatt]

Can anyone tell me what a "prime" lense is? I have been poking around this website after work the last couple nights...there is a lot of good info here.

Prime lens meaning you only have one focal length, you cannot change it. In other words, you cannot zoom in/out with your lens, you have to do it with your feet.

I would put some time into studying the theory to understand the basics of how your camera, lens and generally the light work together. Now, everybody learns in a specific way. I'm an engineer so I like to break down things. What do I do when I take a photo? Composition first? good, let's read some composition rules. Then I have to think about exposure and the things that contribute to it (shutter speed, aperture, ISO). OK, let's dive into those things one by one. Then I need to focus on my subject. Great, let's read about focusing techniques. Then you need to process your pictures. So, let's think about that (software, techniques etc). And then you press the shutter button I would not go into those too deep at the beginning, just try to understand the basics and then in time you can go into details while you practice.

One particular advice is to stay open minded and analyze everything that you read (and also test in practice). There are a lot of resources available on the internet, but whatever is that you're reading try to understand the reasoning when somebody is making a point. Is he bringing some arguments to sustain his view or is just "because I say so"? for instance, you'll be reading that you absolutely need to use filters for landscape photography every damn time. I don't agree with that. I would say "it depends." If somebody does it all the time it doesn't mean you can't get as good results (or even better) by doing something different.

Everybody has their way of doing things which works best for them and you'll have to find yours. As I said before, I'm an engineer so I tend to concentrate more on the technique. I believe this is my strong point and I'm lacking when it comes to creativity and imagination. Perhaps I should do exactly the opposite, but this is just a hobby and I'm lazy. It's easier for me to understand concepts like ISO rather than composition and stuff like that.

Better camera doesn't automatically mean better pictures, although it can help a lot, I don't deny that. If I drive a regular car and you give me a Formula One Ferrari, I will probably drive faster for just a short time. Then I will crash into a tree or something. You have to put some effort into other things, not just the camera. In this regard, I think this forum is a terrific resource!

And most important... have fun !!

PS: if you're into landscapes also look for a steady tripod with good reviews.

I'm sorry. I'm going to need more information on the house panthers.

Some quick snaps with my phone below to show you what he meant. Those two guys are all over my head!

Attached Images

   

---

Last edited by Hattifnatt; 02-19-2019 at 12:39 PM.

[Navmaxlp]

Thank you for the advice...I am just learning about DSLR cameras.

House panthers....per request....hope I uploaded correctly....

A chilling pair to be sure. Please exercise caution. I'd hate to read about a new photographer being involved in a devastating purring incident.

A word of advice here on the photography side of things. While I own and love my 18-135, you aren't likely to purchase your most beloved lens right off the bat. Right now, you don't really know what you are going to love about photography. Many people start out thinking they want to get into one side of photography only to find out they really dig a whole different area with different needs and accessories. Be prepared to change your mind. I think that's why people are advising the 18-135. It's an all around lens that can help you determine what you want. Take a ton of pictures. Then look at the data and you may find you favor one focal length. You may find you'd love to take pictures of flowers but you just can't get your camera to focus that close. You might find you really like taking pictures of landscapes but you can't get a wide enough angle. All these situations have lenses specifically made for them and you need to figure out which ones you like the most. Only shooting will do that.

One other thing. Knowledge is power. There are a million different courses and books available to learn the basics of photography. Everyone has their favorites. mine is Scott Kelby at Kelbyone. I signed up for free. You can pay if you like but, it's not needed for the basic stuff and there's a lot of basic stuff.

That all being said. Have fun. I sometimes wish I could go back and enjoy my photography experience from the beginning again. I love how I got here. I'm not particularly good but, boy do I enjoy it. The journey is the thing. I hope you enjoy yours as much as I've enjoyed mine!

[roxiemyhorse]

Taking pictures is a lot of fun. I did not even bring a camera with me other than my iphone when we wet to Grand Cayman week before last. I really like this pic...mostly because of the color. The blue, blue water...my favorite!!

[ramseybuckeye]

The K-70 is a great choice. The 18-135 will be a much better option than the 18-50 if you can afford it. Although I have never used the 16-85 it supposed to be better yet. The Sigma 10-20 is supposed to be good ultrwide zoom, ultrawides are pretty good for architectural photos and some selective landscapes. You have got some recommendations for the DA15 also, which I agree with. I have a Tamron 10-24 ultra wide zoom which is a nice lens, but after getting the DA15 I rarely use the zoom. Since you didn’t mention longer lenses I would guess that’s not a need, but if that changes the 55-300 PLM was made for the KP and K-70.

And there are all kinds of old manual lenses available on the used market. There are some really good old primes that are inexpensive options. You may not want them for your everyday lenses, but they can be a lot of fun. Another item you will want will be a tripod, when you’re ready for that make sure you get a decent one.

[reh321]

I have the older f/4-5.6mm variant of the Sigma 10-20mm lens; today I would purchase the f/3.5 variant rather than the "slower" variant - it is still $100 less expensive that the DA 15mm. When photographing landscapes, I use it much more in the 10-14mm range than in the 15-20mm range{both photos below were taken at 10mm}
The Swamp - PentaxForums.com
Trees in the Rocks - PentaxForums.com

[FozzFoster]

I have the older f/4-5.6mm variant of the Sigma 10-20mm lens; today I would purchase the f/3.5 variant rather than the "slower" variant

pourquoi?

I was under the impression they are super similar - especially if you're using it on the wide end where the aperture would be around f/4... not much faster than the f/3.5 and I'd doubt the sharpness of these entry level ultra wides is impressive wide open.

Just curious why you show the favour to the the f/3.5!

[Perfessor5646]

I have a K70 (and a K-3ii). I also have a 18-135mm and a Sigma 10-20mm f3.5 that have become redundant. I purchased the 18-135 with the K70 and the Sigma 10-20mm brand new.

(I bought the 16-85 and the Sigma 8-16mm to upgrade them both. Not because I need to but the voices in my head told me to.)

I’ve not been in a hurry to sell them or they’d have been gone by now. Do some more research, get more opinions and PM if you have an interest. If you want to see sample pictures, I can do that too. We might be able to work something out.

John

[mikesbike]

The DA 18-135mm is a way better lens than the DA 18-55mm kit lens, and more versatile than the DA 16-85mm. I have had the small kit lens and used it for some years, even though having larger, more expensive pro-style lenses, whenever I needed more compact smaller carrying in brighter lighting or using flash. I gave it away with an older model compact Pentax DSLR, which I replaced. I already had the DA 18-135mm, which is a unique and very useful lens. I don't know f you live in the US, but B&H of NYC offers a great price on the K-70 with DA 18-135mm combo. A big savings over getting them separately. Your idea of also including a Sigma 10-20mm f/3.5 would be great for taking care of any wide angle need, both indoors and for outdoor use. Its constant-aperture f/3.5 capability throughout its zoom range would be very good for lower light use.

You've received good comments and advice here. But for you to more fully understand the conversation, it is necessary to understand something about how cameras and lenses work and how their properties are applied.

The zoom lenses generally having the finest, sharpest image quality, are the pro-style models by various makers having the widest aperture capability, usually f/2.8 which can also be maintained over the entire zoom range. Note that the smaller the number, the wider/larger is the aperture designation. Such lenses are generally expensive, and their wider apertures necessitate a much larger, heavier lens with a shorter zoom range. The term "a fast lens" applies to the wider aperture letting in more light thus allowing a faster shutter speed under the same lighting conditions. This is a good thing for lower light use with hand-held shooting, and/or for moving subjects, without having to greatly increase the camera's ISO sensitivity to get the same shutter speed increase. Higher ISO settings come at a price of increased noise (grain), and lower image sharpness. Some cameras, like the K-70 and KP excel at holding down noise and also maintaining good image quality at higher ISO settings, (a big plus for them!) but it is always better to have the capability to get your shutter speed up to where you want it, yet with a minimal ISO increase.

In addition to the shutter speed advantage, a wider aperture capability provides the photographer with greater ability to control depth-of-field (DOF). While opening up the lens's aperture will allow greater shutter speed, the other side of that coin is this will simultaneously reduce DOF- that is, how much in the frame of your shot, including the foreground and the background, will be sharp, besides the sharpness of your subject. This is not always a bad thing. Sometimes a photographer will open the aperture more, even in brighter lighting, to deliberately blur the background to make the subject stand out more from it.

The DA 18-135mm. like most zoom lenses, has a variable aperture, which means when set wide open it will change to a narrower value as it is zoomed to a longer focal length (FL). In this case, f/3.5-5.6 throughout its zoom range. However, it is capable of maintaining f/3.5-4.5 from 18-70mm, which is unusual for a wide angle-to-telephoto zoom lens, especially with the fine build quality of this lens, even having weather-resistant (WR) construction. yet it is compact. Most such lenses would have shifted to f/5.6 before getting to 70mm. To get WR construction in another brand like Canon or Nikon, the price starts in the $1,000 range. Same with the K-70 having WR construction, in the other brands, it would again be the $1,000+ range for the camera body.

I have 3 pro-style wide angle-to-(short) tele f/2.8 zoom lenses: 17-50mm, 24-60mm, and 28-70mm, and also the very fine Pentax DA 20-40mm f/2.8-4 Limited. Yet I frequently turn to the DA 18-135mm lens for its versatile zoom range with fine image quality. I don't always need what a fast lens can do. This lens is just the thing for many uses. Its zoom range and fast AF would be great for your cat shots, and also very good for landscape use, since it has good performance even at the frame edges when used between 18-50mm, which is the common FLs for such use. And to get more DOF for landscapes, you would select a narrower aperture where this lens performs admirably, central-area sharpness is outstanding. Tests reveal this lens to perform very well, even at frame edges, in this range. Beyond 50mm edge performance drops off gradually, where with the DA 16-85mm edges would hold up better, especially beyond 70mm, but as you go to longer FLs the edges become less important anyway, while this lens's central area performance remains at the excellent level! In fact, in the central area, it performs as well or better over all than even the DA 16-85mm or other fine lenses.

Another outstanding thing about this lens is its very fast, quiet, accurate auto-focus (AF). One of the best AF performances of all lenses for Pentax, regardless of cost. Once you get the hang of using the shutter button half-press efficiently to achieve focus, with this lens you'll nail your shots with regularity.

As to a prime lens (non-zoom), they are a much older concept, and can allow makers to produce very high quality optics in a very fast lens, while having a comparatively small, lightweight body (until you get into longer telephoto). These can also be fairly inexpensive in a mid-FL model, yet with very fine image quality. One example is the DA 50mm f/1.8 which is not at all costly. It is a fine choice for very low light use, and for portraits. Its wide f/1.8 aperture will provide plenty of aperture option to blur the background to make your subject stand out from it, to the degree that is wished. It is something to consider, perhaps somewhat later after having your equipment for a while.

Please mark this for your reference-

When you get your K-70 and lens(es), after you install the lens and get it powered up, (and BTW, best to get a spare battery), put your mode dial on "P" (program) for fully automated exposure by the camera- not on the green auto mode, which will not allow access to many functions and settings. Open up your rear screen and turn it around so the screen is installed on the back so you can see the display. Now, if you hit the info button, you will have access to settings via the quick-links screen. Then the 4 buttons around the ok button are used for navigation. What you are after is to set up "Fine Sharpening" in the Custom Image menus "Bright" category- having your camera set to "Bright" is best for most uses. Go to that section (maybe already there), hit ok button to open, follow prompt to adjust (probably 'Info" again). Go down to Sharpening and use you rear thumb dial to put an "F" by the "S" for fine sharpening. Hit ok to return and just turn off the camera. This adjustment will provide optimum fine detail in your images. Your camera is probably already set to 3-star finest quality JPEGs.

Now you can take off the lens cap and install the lens hood. You are ready to turn on the camera and shoot some photos. You are welcome to any help you may need at this point. You might even want to use the camera's "SCENE" modes for convenient operation for a period while you familiarize yourself with your equipment, and you can get good results right away. It will have various options including snow scenes, which are now plentiful around here since I live in Michigan. You will soon learn what the camera is doing and why, so you will no longer need to switch on a "SCENE" but can handle the situation faster yourself.

For example, with a snowy scene you will need to override your camera's exposure setting when in "P" mode, with a greater exposure than the camera has determined, by about +1-1/2 or so, depending on the lighting, and percentage of snow coverage. Otherwise, the camera's meter in seeing all that bright white, to compensate will reduce exposure, resulting in gray snow and dark people. With your K-70, you can instantly perform an override either with your exposure comp +/- button, or by decreasing shutter speed and/or setting a wider aperture, as desired. Doing this is amazingly fast and efficient with a Pentax DSLR. You have both thumb and finger controls, which is not so with other brands at this price point, let alone WR construction. Unique to Pentax, all you have to do in the "P" mode is override by using these controls. Tv means Time value or shutter speed. Av means Aperture value. Instead of first having to turn your mode dial to Av or Tv before setting your preference, you can just use your thumb and finger dials to override the camera's settings and adjust as you wish. The camera will instantly switch to Tv or Av mode as you set your preferred value until you return to full Program operation via a touch of the green button, or shut off the camera. This is the exclusive Pentax Hyper System- very fast and efficient.

Don't hesitate to let us know of your decision, and then how you are doing with your new equipment, and we are here for any questions.

There will be many adventures ahead in learning about metering, exposure settings, shooting in Manual mode where you read the meter at certain points in your scene and determine yourself what aperture and shutter speed will be best. And again, we are always here to help.

(Note my edit above to narrower aperture for landscape)

[roxiemyhorse]

Thanks for all the great info mikesbike! I am (thankfully) in south Texas, so no snow here! We last had snow December of 2017. I bugged out of New England in 1993...too cold, too much snow.

Thanks for all the great info everyone!

[mikesbike]

You are very welcome. I am not discouraging you from getting a KP instead- it is a truly great camera. However, it does not have SCENE modes, being designed with advanced and pro photographers in mind who want to add a compact field model. As good as the K-70's build is, the KP's metal magnesium alloy construction, advanced controls, quieter shutter, and other refinements are in another class. You can still shoot with it in the "P" mode, set up "Fine Sharpening", and have the Pentax Hyper System to use, just as with the K-70. It is a marvelous price for what you get. I got the jewel-like silver version, which is a true match for the beautiful silver Limited primes, while the"silver" K-70 is not. But the great deal with the DA 18-135mm lens is somehow not there with the KP, unfortunately.

If getting the KP, I would still recommend the DA 18-135mm. Its compactness is an excellent match for the design concept of the KP.

[Greg1956]

Hi,

I have the K-70 and recently bought a 2nd hand Sigma 10-20mm for Astrophotography.

Whilst I haven't yet used it for Astro work much, I did use it whilst on holidays in January.
I found it to be soft wide open (which is to be expected) and does show distortion at 10mm. But once you move to say 12mm it is no longer noticeable.

Typically at f5.6+ it is sharp across the image and I find the colours match closely to my Pentax DA35 f2.4.

It is a good buy in my opinion and will let you get just a bit more in, ie below the standard 18-xxxmm lenses.
And definitely good for Astro work.

Greg

[rickc118]

Welcome to PF, and congrats on your K-70, which is a great camera!


I use three of the lenses mentioned quite a bit in this thread: the 18-135mm WR, the Sigma 10-20mm, and the 55-300mm PLM, used on a K-70. I also have a couple of prime lenses, and the 18-55mm. The lens that spends the most time on my camera (by far) is the 18-135mm, followed by the 55-300mm. Of course, which lens you will want to use really depends on the situation and what you intend to shoot, but the 18-135mm has versatility in its favor.


My suggestion would be to get the 18-135mm first, then go out and shoot as much as you can. Wait for awhile to purchase more glass, as I'm guessing you will be better positioned to figure out what you want after learning more about your new camera and what you enjoying shooting.


Good luck and have fun!