[jatrax]

I just didn't expect this much difficulty on such an easy scene.

It looks easy to you, to the camera meter it is incredibly hard. You have white boat with a very dark stripe with no blend. So if the meter sees the white you get one exposure if it grabs the dark blue stripe you get something completely different. Add in that you are handheld and shooting a boat that might be moving a bit and it is easy to see why you are getting the results you are. Matrix or center weighted would have averaged the white/dark blue and got something that worked. But spot is going to grab one or the other and thus show a correct (gray) exposure for that tiny portion of the image.

[jgnfld]

Curious, applied the same overlay to the first picture, and the "metered" area is dominated by the dark blue stripe on the boat, not the white area. Thusly, shouldn't that have metered as darker than the second pic? Why did the camera choose ISO 100? Curiouser and curiouser...

---------- Post added 08-08-17 at 09:54 AM ----------



Thanks, Adam, this may be sound advice. I need to do more controlled testing to determine what's going on. I did switch to spot metering because matrix metering was not recording correctly either, but I'll revisit that setting and try again. My primary subject is often a black dog, and as anyone who shoots black dogs regularly can tell you, they can be a royal PITA to get the exposure right on. I just didn't expect this much difficulty on such an easy scene.

"Spot" metering is not a point but rather a small area. I cannot find how large on a Pentax sensor however some Nikon cameras report the "spot "covers 4mm on the sensor. So you need to look around the center points you are drawing, not just the point itself.

[Qman]

The whole point of using a dslr is that it gives the photographer the tools to be creative.
Regardless of the camera set-up, before you press the shutter you can see the ISO, aperture, shutter speed, and exposure compensation in the viewfinder. On the K-70 it is quite bright and clear.
You would have seen that, for the second photo, the f stop and ISO weren't what you wanted. You then have the opportunity to make changes.
There are lots of settings that could throw things off. In the end, you can quickly change the settings to get what you want. Start by dropping your max ISO. Then, if necessary adjust the aperture. Later, analyze why the settings were so far off. Since you've had the same issues with two different cameras it seems likely that it isn't a problem with the camera. There have been a lot of useful responses in this thread. Abandon spot metering. Either don't use auto ISO, or limit the max to say 400 if you're shooting in daylight. Choose aperture priority if that's most important to you. Choose Sutter priority if, for example, you're shooting a very long lens or fast moving objects. If you just quickly want a good photo then set it to P mode and it will likely do a good job, as long as your auto ISO is set to a reasonable range.
I tend to use exposure comp instead of spot metering for things like black dogs or the moon. That way, if I forget to set it back to zero I can see it in the viewfinder before I take a picture, and quickly reset it without taking my eye out of the viewfinder.
Hopefully you can give some of these suggestions a try and see if it helps. Then report your results back to the thread. I'm sure we'd all like to hear how you make out.

[Wolfeye]

I did take the suggestion and changed over to matrix metering. Overall I'd say there's definite improvement, but I did see some irregularities. Just nothing of the same magnitude that spot metering caused. So I am keeping the K-70 out of Precision's moderately-evil clutches. For now.

OTOH the 55-300 (newest version) has a fault - when unlocked there's no stop at 55mm - it goes all the way back to the locked position without the unlock button having to be pressed. If anyone has a quick fix for that I'd love to hear about it, else it goes back for repair.

[jgnfld]

I did take the suggestion and changed over to matrix metering. Overall I'd say there's definite improvement, but I did see some irregularities. Just nothing of the same magnitude that spot metering caused. So I am keeping the K-70 out of Precision's moderately-evil clutches. For now.

OTOH the 55-300 (newest version) has a fault - when unlocked there's no stop at 55mm - it goes all the way back to the locked position without the unlock button having to be pressed. If anyone has a quick fix for that I'd love to hear about it, else it goes back for repair.

You can send it back for "repair", but since there is no such stop in the lens there isn't much they can do to make the fix you want.

The stop is designed to click in and to keep the lens retracted when fully closed and not in use. It is not designed to serve as a stop at 55mm. There is a palpable notch at 55 as you zoom down which tells you when you are there. If you don't feel it then you might need to send it in for repair. But if you don't like that design aspect, you should return the lens to the dealer for a refund instead.

[MrB1]

For general shooting, I agree with the comments that Spot Metering is the problem here. However, contrary to some of the negative comments about Auto ISO, it has never yet caused me any concern. For the majority of my outdoor shooting, done using Aperture Priority Mode, the K-70 Auto ISO is set between 200-3200 ISO, and the camera always appears to use the lowest ISO value consistent with its selection of a shutter speed appropriate to minimise camera motion blur.

Philip

[Wolfeye]

You can send it back for "repair", but since there is no such stop in the lens there isn't much they can do to make the fix you want.

The stop is designed to click in and to keep the lens retracted when fully closed and not in use not to serve as a stop at 55mm. There is a palpable notch at 55 as you zoom down which tells you when you are there. If you don't feel it then you might need to send it in for repair. But if you don't like that design aspect, you should return the lens to the dealer for a refund instead.

Interesting. I could have sworn it worked that way before and had suddenly changed. Nikon has a similar lens and I know it behaves that way, so perhaps I'm mistaking the functionality. Seems odd though. I'll see if mine has the notch. It feels to me like a defect to be zooming out and have the viewfinder suddenly black out b/c you went too far. Nikon's design is better. Wonder what logic Pentax applied to design the lens so that when you're zooming out you suddenly can lose all ability to take the picture, with only a faint "notch" to tell you you should have stopped...

[MrB1]

You are correct wolfeye - with the lens extended for use, when turned back it stops at 55mm until the button is pressed to release it to turn to the fully retracted locked position.

Philip

[Wolfeye]

You are correct wolfeye - with the lens extended for use, when turned back it stops at 55mm until the button is pressed to release it to turn to the fully retracted locked position.

Philip

Thanks! I thought maybe I'd gone nuts. Not the first time that has crossed my mind.

[jgnfld]

You are correct wolfeye - with the lens extended for use, when turned back it stops at 55mm until the button is pressed to release it to turn to the fully retracted locked position.

Philip

On my copy the lock needs only to be pressed on release. When zooming down to 55 there is an internal notch of some sort that is entirely unaffected by pressing the button. It self clicks in when you totally close it. I have no trouble with zooming it in and out and lately I have been using it a lot while singlehanding a 27' sailboat in coastal waters up to 10 miles offshore where there obviously is a lot of other motion going on in several directions at the same time.

This shot required quickly zooming down as a minke suddenly decided to examine my boat from about 7 or 8' underwater. AF worked fine enough through the water that with some post processing work the detail was about as good as the detail gathered by eye in that situation. Even so, couldn't get the whole whale (which was longer than my boat) in the pic with such short notice as it passed by only a short distance away.




Here is a shot of a wharfmate's boat taken from several hundred yards away as the sun broke through the clouds...



And another of some small boat fishermen about 200 yards away on a dead calm bay in the morning. The small automated lighthouse in the bokeh in the background is 7.7 miles away according to Google Earth.




I love this lens.

[MrB1]

Having checked it carefully again just now, the 55-300 RE works as described in Post #23. When in use, the zoom-in stops at 300mm and the zoom-out stops at 55mm; pressing the button releases it from the 55mm stop, so that the lens can be properly retracted and locked closed. The 18-50 RE works in exactly the same manner in use - stopping at 50 and at 18; pressing the button releases the 18 stop, so that the lens can be retracted.

Philip

[jgnfld]

Having checked it carefully again just now, the 55-300 RE works as described in Post #23. When in use, the zoom-in stops at 300mm and the zoom-out stops at 55mm; pressing the button releases it from the 55mm stop, so that the lens can be properly retracted and locked closed. The 18-50 RE works in exactly the same manner in use - stopping at 50 and at 18; pressing the button releases the 18 stop, so that the lens can be retracted.

Philip

H'mmm...different manufacturing lines? Any Pentax rep reading?

Anyway, I have absolutely no problems with mine acting a bit differently but we'll see going forward. I have a 2 year warranty in Canada so there's time.

[Wolfeye]

I've been happy with the lens and as it's still under warranty, I'll send it in for repair. I hate doing that, what with the horrific stories I read about Precision camera. Why can't Pentax do what Canon has done, and open up a brand new COMPANY-run repair center?

Rhetorical question, BTW. They don't have the money.

Edit: Jesus, this goes NOT well from the get-go. Went to Precision's website, selected "Lenses" for a category, but the "Model" dropdown list doesn't have the HD PENTAX-DA 55-300mmF4.5-6.3ED PLM WR RE! So I selected "Lens not listed" which takes you to a page where you can "Contact Us" so I told them about the missing lens... then I realized the "Contact Us" wasn't even on Precision's website, it's on Ricoh's. So now they have an email about "some lens not being in a dropdown list" and probably no clue WTF I'm talking about...

[Wolfeye]

Too funny. Ricoh tells me to call Sun Camera in Canada. I tried to find an email address to try and reach Precision - and as I totally expected, there's no email support anywhere on their website. Total incompetence.

[Rvtazz]

Nope. I am not confused. The second shot is 1/500 sec, shutter-priority mode. The auto ISO selected by the camera was 1600, and it selected f25. Spot metering meters just the center part of the scene, as shown in this mockup. There's nothing there that suggests such a high ISO and small aperture are required. Any other camera might set this to f11 at ISO 400.

Thats what you get trusting camera software ,just put your dial to M and watch your lightmeter ,no more bad surprises then lol