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03-23-2014, 11:18 AM   #1
Tarag1
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KX F-stop will not adjust!!! Rant big time.

Hello all,

I have a pentax KX and I cannot get the F stop to go below 5.6 in Av mode!!! When I go to portrait mode, again no way to adjust the f-stop. What ends up happening is my exposure time is really slow (to let in more light) and my pics are super blurry. I am trying to decide if it's me because I'm a novice or if it's just this camera. When I get a good shot (1 in 90 pics), they are awesome and super high quality. Everything else is just crap. The exposure is wrong and the shot is blurry. Don't even get me started on the auto focus--so slow (I miss shots of my 7 month old because the camera will not fire when I press the button to take a photo) or it focuses on her nose rather than her eyes. I spend hours in post-production trying to clean up these shots rather than tweaking them here and there.

I am just about ready to sell my gear and get a nikon d7100. I really do not know what to do. I got the pentax based on the quality of the sample shots I saw on amazon and dpreview. Just amazing.

Any thoughts on this? Is it me or the camera?

Thanks so much to all who respond, I really appreciate it!!! --Tara


Last edited by Tom S.; 03-23-2014 at 01:06 PM. Reason: Swearing removed.
03-23-2014, 01:08 PM   #2
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Welcome to the forum. Be advised that this is a family friendly place and we do not allow swearing or inferred profanities. Thus, your post has been moderated.
03-23-2014, 01:25 PM   #3
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A flash is alarming to babies, Tara, so crank up your ISO. Sounds like you need to study and read the basics of not just your KX, but photography in general.

Last edited by clackers; 03-23-2014 at 04:15 PM.
03-23-2014, 03:17 PM   #4
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The shot is blurry because of shutter speed. I would readily admit that the Nikon 7100 is a better camera. As far as the lens going under 5.6 - you are probably using the kit lens with it extended to 55mm which is maximum aperture. That is a lens issue. Most kit lenses are 18-55 are 3.5-5.6 regardless of manufacturer. Often times too, those amazing pictures you see come from awesome lenses. I Had the k-x and it is a great camera, but you need great glass for great pictures. Also you need to read about shutter speed, ISO, and aperture so that you understand how they relate. That should get you started.

03-23-2014, 04:18 PM   #5
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QuoteOriginally posted by First Poster Quote
I have a pentax KX and I cannot get the F stop to go below 5.6 in Av mode!!!
As it was mentioned before, you're probably using the kit lens extend to 55mm. f/5.6 is the minimum. Which brings out another problem, 5.6 doesn't let much light in, making it very hard for your camera to focus.

QuoteOriginally posted by First Poster Quote
it focuses on her nose rather than her eyes.
No auto-focus system will know instinctively what to focus on... It usually pick whatever is closest with a decent contrast ... and a nose is a very nice target. But at f/5.6 nose or eye on a baby shouldn't make a huge difference.

Now, what can you do about this? Getting a 7100 may work better (newer tech, better in low light) and it's more than twice the price of your Kx but it will more than likely come with a kit lens, which will be 3.5 to 5.6, you'll be back to square A.

Your first step is to understand what your problem is, it's not your camera, it's your lens, it's your light, it's your focussing method. Since you can't change your lens, you need to adjust the rest. Interior photos are demanding because even a well lit room in a house is very dark for a camera. When taking pictures of a baby with a slow lens, I will be looking at getting at least 300 watts of lighting, or a flash. Also, try using AFS and use "select" or "centre" for your focussing mode. Also make sure that the SR icon shows ON.

One thing that really grinds my gears is when someone threatens to go to Nikon or Canon because the Pentax doesn't take nice photos... People need to understand that the body you're using is the least important thing in photography. Hardware wise, a good lens will make more difference than a better body. And most important, you need light!!!

Often time beginners don't understand this... "well my $2800 Nikon with a $1200 lens take better pictures than my $400 Pentax with a $75 lens so the Pentax was a POS" Of course it does... now try the $400 Pentax with a $1200 lens and tell me if it is still bad. Similarly priced camera from any manufacturer will have similar performance. Sure Pentax's AF isn't the best... but in low light, none will be great.

Also, from my experience, Sony STL camera have the fastest focussing camera I have ever tried (less than $1000) so you should consider an A57 or similar.

Photography is the capture of light... the more light, the better your images. Try a better lens, try a 50mm f/1.8 for example, they're great indoors. Pay for round-trip shipping and I lend you mine...
03-23-2014, 10:18 PM   #6
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If you're using an 18-55mm at 55mm, then the fastest F stop is F5.6. You can't go lower because of the lens.

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03-23-2014, 11:57 PM   #7
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QuoteOriginally posted by Adam Quote
If you're using an 18-55mm at 55mm, then the fastest F stop is F5.6. You can't go lower because of the lens.
Yep, Nikon's 18-55mm DX kit lens would be the same.
03-25-2014, 01:42 PM   #8
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Try to learn how to use AV mode, adjust to largest aperture (smallest numerically) and increase the ISO to 800 or 1600, the K-x has good high ISO performance so it should be ok but not ideal. More light and normal (100 to 400) ISO is best.
If you shoot with the lens at 18mm you CAN use your 3.5 aperture (f-stop)...if you zoom to 55mm, you are restricted to 5.6.

If you master your Pentax you can create much better photos than a novice with a Nikon or Canon...
My point is not to imply that Pentax is better, just that they are all only as good as the person taking the photos...

If you look at my "Pentax Photo Gallery" photos, you will see that many of my photos that were accepted were taken with a K-x using the 18-55mm kit lens.

03-25-2014, 02:06 PM   #9
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Overall, I am +1 with what Skid has said. I shoot with a K-x myself, generally with the kit lens.


While your lens is not capable of shooting with an aperture below 5.6 when you have it set for the lens' greatest focal length of 55 mm (which will give you the greatest close-up view from a given distance), your lens can shoot with an aperture as open as 3.5 (still not the greatest, perhaps, but compare to 5.6) at its widest angle setting of 18mm. If your subject now seems to be too far removed you can get closer to get better detail. (Another option is to crop the image to improve the focus on your subject, but you really want to learn to shoot closer when you can). This alone may not make enough difference, however.


As for the focus and blurriness, young children can be challenging due to their propensity for movement. There can also be artifact from camera shake and the propensity for camera shake increases with longer shutter speeds. And lower light situations, such as shooting indoors, require longer shutter speeds (all other things being equal). And longer shutter speeds also give your subject more opportunity to move around which can cause motion blur. To reduce this problem, I often shoot in shutter priority (Tv) mode. Often I will use a shutter speed of 1/125 of a second but I will go as low as 1/80 or 1/60 of a second if I need to. In shutter priority mode your camera will adjust the Aperture and ISO settings (if you are set to Auto-ISO) to get a good exposure (meaning a well-lit scene, as determined by the camera's sensor).


ISO is a measure of light sensitivity. A shot taken at a lower ISO setting (the K-x is capable of shooting with an ISO as low as 100) requires a longer shutter speed and/or a wider aperture to get as good an exposure (meaning well-lit) as the same shot taken at a higher ISO. However, as ISO increases you will eventually start to see unwanted graininess and "noise" (comparable to the noise on old pre-digital TVs). Still increasing your ISO may be important to your getting good tot shots (especially indoors). Increasing the amount of light (whether with or without flash) will also help.


So I would advise that you shoot in shutter priority (Tv) mode with as short a focal length as possible (moving closer to your subject if you want a more close-up view) and set your ISO setting to Auto-ISO with a range from 100 (or 200) to 1600 (or higher if you are satisfied with the results; use 800 as the upper end of your range if you are not satisfied with an ISO of 1600 but be aware that then you will encounter more situations in which you will need to rely on your flash or on other light sources if you can get the shot at all).


With this setup, if you try to shoot at the pre-set shutter speed (say 1/125 sec) and the camera cannot get enough light for a good exposure at your maximum ISO setting at the camera's maximum aperture (which will vary according to the focal length you have the lens is set at), you will see a blinking of the aperture setting reading on the back screen of your camera. Your options (assuming you want to get the shot) will be: 1. If possible, reduce your focal length to get a wider aperture; 2. If possible reduce your shutter speed (but definitely not below 1/50 or 1/60 of a second if at all possible); 3. Increase your ISO; 4. use your flash; 5. find additional lighting.


My one other piece of advice is to learn from your successes and failures. Start by looking at your shots that have come out well and look at them in terms of what settings (shutter speed, aperture/f-setting, and ISO were used) and what was the situation in which the photo was taken (being mindful of the amount of available light, the amount of motion taking place, and whatever other factors might have worked to create a successful shot. Find some similar shots that did not work out. Ask yourself what was different in terms of both camera settings and other factors including motion and light (trying to be sensitive to indirect factors lack the drop in light through a window as a cloud passes over the sun, or the change in light and shadows as the time of day changes, or whether shades or curtains are open or drawn; and also the direction of light on your subject). As you do this you should find yourself developing a better understanding of what shots will work and at which settings, and a better understanding of what has gone wrong when a shot does not work out.

Last edited by Bill2849; 03-26-2014 at 02:42 PM.
03-25-2014, 07:55 PM   #10
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QuoteOriginally posted by Tarag1 Quote
Hello all,

I have a pentax KX and I cannot get the F stop to go below 5.6 in Av mode!!! When I go to portrait mode, again no way to adjust the f-stop. What ends up happening is my exposure time is really slow (to let in more light) and my pics are super blurry. I am trying to decide if it's me because I'm a novice or if it's just this camera. When I get a good shot (1 in 90 pics), they are awesome and super high quality. Everything else is just crap. The exposure is wrong and the shot is blurry. Don't even get me started on the auto focus--so slow (I miss shots of my 7 month old because the camera will not fire when I press the button to take a photo) or it focuses on her nose rather than her eyes. I spend hours in post-production trying to clean up these shots rather than tweaking them here and there.

I am just about ready to sell my gear and get a nikon d7100. I really do not know what to do. I got the pentax based on the quality of the sample shots I saw on amazon and dpreview. Just amazing.

Any thoughts on this? Is it me or the camera?

Thanks so much to all who respond, I really appreciate it!!! --Tara
I am also a beginner who owns a K-x and wanted better pics of my baby. I ended up trying to find a better lens to use indoors. I settled on the Pentax SMC-P FA 35mm F2.0 -- a prime lens. I waited to buy until I found a decent used one (on ebay... before I found the pentax forums!). With this lens I've take some beautiful pictures of my baby in my house which tends to have very poor light. Sometimes I do need to push the ISO up a little higher to 3200 or more to get a decent enough shutter speed to avoid blur. You do get some noise at higher ISO but it's better than only getting blurry shots.

I think that the DA 35mm F2.4 would probably be similar if you were on a budget.

The others who have responded have given you excellent advice. My best advice is to try to find a lens to better match what you want to do. You would surely need to do this regardless of what camera you use.
03-27-2014, 03:44 AM   #11
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The DA 50 f1.8 should be your next lens, Ostromark.
03-27-2014, 07:18 AM   #12
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QuoteOriginally posted by First Poster Quote
I am just about ready to sell my gear and get a nikon d7100. I really do not know what to do.
That won't solve your problem. Basically, a DSLR is a DSLR. Learning the basic rules of how cameras and lenses work is the key. As others have mentioned, the 18-55 kit lens has a max aperture of 5.6 at the long end. I don't know if that's the lens you're using, but if so, that's what's going on. That said, there's nothing wrong with the kit lens. The kit lens is perfectly capable of taking good photos, as long as you work within it's limitations. If you learn how to use manual focus, you don't need to spend a fortune to get a good "fast" lens, either.

As far as the AF being off, unless you have your AF point set to center, the camera has to guess what you want to focus on, and there's no way for it to actually "know". Set your focus point to center, press the shutter release halfway down with the thing you want to focus on in the middle of the frame, then without releasing the shutter release, recompose and shoot the photo. I much prefer the center point AF mode anyway, and just leave it there. Anything else is a crapshoot.

There are numerous websites where you can learn about camera settings and photography in general. I learned from an excellent old Time-Life series of photography books many years ago. They're pre-digital, but will give you a good grasp of the mechanics of photography.

Good luck,
Bob
04-08-2014, 08:10 PM   #13
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The short answer to your question is it's about 50% you, and 50% your lens choice. The kit lens from EVERY manufacturer is designed to be cheap and look good with plenty of light (i.e. outside). The KX is definitely not your limit. You need to set ISO up around 800 or 1600 at least, and get a lens with a smaller aperture number (larger diameter hole for the light to go in). Below is a shot I took inside the US Air Force Museum with a KX and a Sigma 30mm set at f1.7 and ISO800. Keep in mind that it is almost dark in there, much darker than a normal house. You can see that the shot is sharp in the focus area.

One more very important part of technique is your posture and breathing. It can make a huge difference in how still your camera is. When you are indoors, it is so very important. Heie did a whole article on it here on the forum. Same techniques that they teach snipers to shoot work for cameras. Read it here

Also, learn the exposure triangle, it's the basis for shooting anywhere.

04-09-2014, 05:31 AM - 1 Like   #14
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So, yes, its all you. You need to learn that the lens has a mechanical aperture limit. Bright lenses cost a lot more, of course, because they are harder to make. The best budget lens for low light photography is probably the DA 50mm f1.8, its also a great portrait lens.
Secondly, you need to learn about ISO and how to hold the camera to get clear photos even in low light. Or use a tripod.

Also, 1 good photo in 90 is not bad for a beginner. If you expect to take only glam art photos, that is just a completely silly expectation. There is a reason why photography is such a big business - because it is more than just "herp derp I bought a Nikon now all my photos are pretty!" - it takes skill and experience
04-11-2014, 08:23 PM   #15
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Tarag1: The most important thing you need to learn and understand about photography is that it is almost constant compromise.


Compromise in camera settings, compromise in composition, compromise in gear available vs. budget, etc.


On a side note in regards to blurriness, going with a D7100 would actually be a step backwards (unless you have deep pockets to buy all VR lenses), because that camera does not have built-in IS/image stabilization like your Kx does.


Also understand, like what others have said, that all equipment has its limitations. Built-in IS is not a cure all either as you are probably seeing. It can only help you so far, and even that is dependent on you utilizing good camera handling techniques. (ex.: not pressing the shutter release but squeezing it, holding still til you know the camera has completed taking the shot, keeping the elbows in and actually looking through the viewfinder instead of just using the back LCD to compose so you have greater stability, etc.)


Don't lose hope as a beginner because we were all that at one time and we stopped stumbling, so you can too. Have patience.
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