[DWS1]

I've never worried too much about which aperture setting is the exact sweet spot of any particular lens. I just know from shooting many different lenses for many years that just about all of them produce the sharpest images when used in the middle third of the aperture range, and from what little I know about lens design, this is where the manufactures tend to optimize their designs. Better quality lenses tend to have a wider optimized range, whereas lower quality lenses tend to have a much narrower one. For me, aperture selection is a very small part of the total creative decision making process of trying to make an image express the vision in my head.

[rogerstg]

I tried a monopod for the first time yesterday, with the ball-head just loose enough that I could follow the movement of the bird. I did find myself getting frustrated at having limited freedom of movement with the monopod, but I also finally got a sharp photo of a bird I'd been trying to capture for over month!

Congrats on the great shot!
FWIW, a technique that I use is to put the ball head all the way over into the detent and mount the lens to that. Leave the tripod collar slightly loose so the camera can be leveled and leave the ball head slightly loose to be able to adjust aim up and down. You need a sturdy ball head to make this work well. It gives you flexibility to follow movement similar to a gimbal head.

A camera safety note: the release plate should be angled so that the plate release knob is pointing up and not down. If down, it can rub against the monopod or ball head body and loosen the release plate.

[ChristianRock]

Lens copy variation says that even if there was such a chart, it doesn't mean your lens would fit that chart...

[pschlute]

I guess I was looking for excuses other than user error and my inability to hold the 150 mm-450 mm still

That is a big lens to hold steady without a monopod or tripod. In less than ideal lighting conditions you may struggle to keep the shutter speed up high enough. At 450mm you should not be using slower than 1/500 even with SR enabled.

A few things you can try are:

Use TAv mode. This will allow the shutter speed and aperture to remain constant and ISO will change according to the light. The K1 has excellent high ISO capability. A slightly noisy sharp shot is better than a noiseless unsharp one. Noise can be dealt with in PP software processing.

If your ISO is too high , dial in maybe -1/-1.5 of underexposure. Then bump up the exposure in PP.

Do some Autofocus testing at home with the camera on a tripod (use 2 second timer) to make sure your AF is spot on. If there is any Front or back focus issues you can adjust with the AF/FA (auto-focus/Fine Adjustment) menu.

I see you use Photoshop , Adobe Camera Raw. Are you applying any output sharpening to your images ?

[SpecialK]

There was also a post some years ago of a chart with a vertical bar for each lens and the aperture in the vertical axis. The apparent sharpness or LPI or whatever the parameter used was color coded (red/yellow/green) for each aperture of a lens. It indicated the best range was about 2 stops down, until diffraction started kicking in smaller than f8. The 40 Ltd was particularly ugly wide open per the chart :-)

[D1N0]

For sharpness it depends on pixel size. The larger the pixels the further you can stop down before diffraction starts blurring the image because pixels are too small to be resolved. So the sweetspot on a Ist D may be F9 while it is F5.6 on a Pentax KP. It doesn't mean the IST is sharper than the KP btw.

[Alex645]

Is there a chart somewhere that lists all the Pentax lenses and their aperture sweet spot?

The problem with most published tests is that they are based on one lens using one methodology. But if you look at all the individual tests across many makes and types, there are certainly patterns and trends.

With prime lenses generally a couple stops from either max or minimum aperture will show very good resolution from the center to the corners. So on a fast f/1.4 prime, that can start around f/2.8 or f/4 thru f/8, but on a slower f/2.8 prime, more like f/5.6-f/9.5.

With zooms this is still a safe generalization, but there are more exceptions and conditions and if you're starting with f/4, you won't see that sweet spot until the f/8-f/11 range. I've also seen different design philosophies in zoom lenses make this generalization false.

For example, I've seen many Canon kit lenses perform best at the extremes. They know most beginners shoot at the extremes and rarely in-between so they design for the shortest and longest focal length. With telephotos or telephoto zooms, they know no one can practically shoot with small apertures and the resolution due to diffraction is pathetically bad stopped down.

Depth of field, however with a longer focal length is going to appear very shallow, so most photographers will not be shooting wide open either, so the optical designers are really honing in on the usable apertures for most photographers.

Instead of worrying about the sweet spot, I think most photographers would most benefit from knowing the sour spots and almost always you can count on the last 2-3 stops on the small end. If you care about edge to edge sharpness, then you can almost always include the largest aperture and usually the one stop down from there.

But again, keep in mind zooms also have their own sweet and sour focal lengths which will complicate any aperture assumptions.

[RICHARD L.]

Experience teaches you where a particular lens will perform at its best. For example, my FA* 300 mm f/4.5 peaks at f/8, its performance doesn't get any better if I stop-down more, so no use for that. Exactly the same with my 67 M* 300 mm f/4 lens: f/8 is its optimum f/stop. I just got a new for me, second-hand DA 55-300 mm f/4-5.8 HD that I tested on a tripod at all apertures and focal lengths on an old flour mill (that serves as my "brick-wall" target) and I found f/11 is optimum up to 200 mm FL and f/16 is best at 300 mm FL. So simply take the time to test your lenses on a fixed subject like a building at all apertures in controlled conditions (ideally on a bright day with a tripod) and determine their best performance range for your usual shooting conditions.

Regards

[Gary H Perth]

I usually hang around those two f-stops, unless I need faster for low light or background blur, or a narrower aperture for more DoF.

Pretty consistent with the BigMackCam tables and with common practice. Quite often, regardless of the lens, I just set F8 and worry about the focus and movement of either subject or operator.

[MossyRocks]

I guess I was looking for excuses other than user error and my inability to hold the 150 mm-450 mm still. I'm getting better at it but was hoping perhaps there was a silver bullet (other than a tripod and/or stronger arm muscles).

I wouldn't try to hand hold my 400 but then it is a special monster and I am a big guy who was big into power lifting for years.

[normhead]

Experience teaches you where a particular lens will perform at its best. For example, my FA* 300 mm f/4.5 peaks at f/8, its performance doesn't get any better if I stop-down more, so no use for that.

You stop down for more depth of field. The diffraction limit for both APS-c and Ff is between ƒ5.6 sand ƒ8 so you're bound to have a slight drop off at ƒ11. But if more of the scene is in focus based on a wider depth of filed, the slight loss of detail may be made up for by more the subject in focus. You may not see that shooting a flat surface head on. Definitely shooting macros, ƒ11 or ƒ16 can be the best image. IN a few cases even ƒ22 won out.

I shoot many small flower images at 5 different ƒ-stops, and sometimes ƒ22 is the best image.

[RICHARD L.]

In the kind of pictures I take mostly, DOF is never an issue with telephoto lenses, only with WA where I tend to stack a foreground anchor with a sharp middle ground and background. (Picture taken @ f/8 on a K3).

[eyespywithmyi]

Congrats on the great shot!
FWIW, a technique that I use is to put the ball head all the way over into the detent and mount the lens to that. Leave the tripod collar slightly loose so the camera can be leveled and leave the ball head slightly loose to be able to adjust aim up and down. You need a sturdy ball head to make this work well. It gives you flexibility to follow movement similar to a gimbal head.

A camera safety note: the release plate should be angled so that the plate release knob is pointing up and not down. If down, it can rub against the monopod or ball head body and loosen the release plate.

Thank you!! OK I need to figure out what a detent is and figure out the specifics of what you're saying here. I have had this tripod for one week and it's my first one, I appreciate the notes though and will look into it all.

---------- Post added 06-16-20 at 06:49 PM ----------

That is a big lens to hold steady without a monopod or tripod. In less than ideal lighting conditions you may struggle to keep the shutter speed up high enough. At 450mm you should not be using slower than 1/500 even with SR enabled.

Wow, lots to unpack here, thanks for all of it!! I've been using it handheld down to around 1/300, not always successfully, mind you, I'll lower my threshold on that.

A few things you can try are:

Use TAv mode. This will allow the shutter speed and aperture to remain constant and ISO will change according to the light. The K1 has excellent high ISO capability. A slightly noisy sharp shot is better than a noiseless unsharp one. Noise can be dealt with in PP software processing.

If your ISO is too high , dial in maybe -1/-1.5 of underexposure. Then bump up the exposure in PP.

I've been nervous about using too high ISO but you're right. I did use 10,000 ISO in the woods recently and got some great, if a little noisy, shots of an owl that were stone still. I've also only been shooting on Av but will try TAv, I kind of forgot about that option. I'd also forgotten about exposure compensation until about 3 weeks ago but am now using it pretty consistently, to good effect. Good reminder about TAv.

Do some Autofocus testing at home with the camera on a tripod (use 2 second timer) to make sure your AF is spot on. If there is any Front or back focus issues you can adjust with the AF/FA (auto-focus/Fine Adjustment) menu.

I read about this possible issue on this forum but haven't tried such a test, I don't quite understand how to test it but will look for a step by step and try it

I see you use Photoshop , Adobe Camera Raw. Are you applying any output sharpening to your images ?

I play with noise reduction by adjusting the Luminance setting, have used it pretty consistently. But I don't understand the other sharpening tools. I tried changing the sharpening amount and tweaking some of the sliders in that section and honestly thought it all looked worse so I can't say I have a real understanding of how to use it. It's on my list of things to investigate. Post processing in general is something I am just really starting to spend more time doing and I learn a little more every time but there is so much to learn! Hey, thanks again, I appreciate you taking the time to give me these tips.

---------- Post added 06-16-20 at 06:52 PM ----------

Experience teaches you where a particular lens will perform at its best. For example, my FA* 300 mm f/4.5 peaks at f/8, its performance doesn't get any better if I stop-down more, so no use for that. Exactly the same with my 67 M* 300 mm f/4 lens: f/8 is its optimum f/stop. I just got a new for me, second-hand DA 55-300 mm f/4-5.8 HD that I tested on a tripod at all apertures and focal lengths on an old flour mill (that serves as my "brick-wall" target) and I found f/11 is optimum up to 200 mm FL and f/16 is best at 300 mm FL. So simply take the time to test your lenses on a fixed subject like a building at all apertures in controlled conditions (ideally on a bright day with a tripod) and determine their best performance range for your usual shooting conditions.

Regards

I have this exact test on my to-do list! Time to get methodical. Thanks

---------- Post added 06-16-20 at 06:55 PM ----------

I wouldn't try to hand hold my 400 but then it is a special monster and I am a big guy who was big into power lifting for years.

I do a lot of crawling through the woods looking at teeny songbirds so it's not always practical to carry and/or use a tripod. I will be carrying the monopod most of the time now, to use in more challenging lighting conditions, at least.

---------- Post added 06-16-20 at 06:58 PM ----------

I'm impressed with getting any tern in flight.

RIGHT?! They're so dang fast, and they do barrel rolls at a moment's notice. They're ever so slightly easier than swallows, though, which I was obsessed with trying to capture in flight but settled for really good stills while perched. Why couldn't I be obsessed with photographing, say, Robins ...

[rogerstg]

OK I need to figure out what a detent is and figure out the specifics of what you're saying here.

Here's a

You Tube

You Tube

that might help. What I wrote of begins at 2:05.

[pschlute]

I tried changing the sharpening amount and tweaking some of the sliders in that section and honestly thought it all looked worse so I can't say I have a real understanding of how to use it. It's on my list of things to investigate

My suggestion would be to leave the sharpening settings in Adobe camera raw at their default settings. This is called "input sharpening"

After you have done all your other editing, including resizing, and have created a jpeg file all photos will benefit from some "output sharpening". PS has many tools but I like the USM (unsharp mask) tool. You find it in the main menu bar....Filter/Sharpen/Unsharp Mask. I generally use settings of :

Amount 25-50
Radius 0.60
Threshold 1

If you have say a bird against an out of focus background, you can do the sharpening on a new layer with a mask. Invert the mask so it is black, then paint over the bird with the brush tool in white. This means you will only be applying the sharpening to your subject and not the background.