Picked up the Pentax 55-300mm PLM lens
I'm still testing the 55-300PLM (I announced on my YT post that I bought one, for those that missed that). So far I have experimented with four scenarios - 260mm and 300mm at f6.3 and f8. I've read that a few people find it sharper when they back off from 300mm a little bit, and others that said sharpness peaks at f8. PentaxForums in-depth review cites f8-f11 at 300mm for peak sharpness. https://www.pentaxforums.com/reviews/hd-pentax-da-55-300mm-f45-63-ed-plm-wr/sharpness.html
I haven't done any laboratory tests in my backyard yet, just some real world photographing a patient heron. The results so far were interesting, but maybe a little tainted because of shooting at extremely high ISOs. I won't use this lens as a replacement for my morning bird photography, it's just not nearly as fast as the DA* 300mm f4. But I plan to use it for day time hikes where I want a zoom, want something light, and have plenty of light to work with.
I didn't see much noticeable difference between 300mm and 260mm cropped in to match the field of view. Both for matching aperture values. But could be because high ISO is making it too muddy to tell.
But there is a substantial difference between f6.3 and f8 at 300mm. Even though the F8 shot was at a higher ISO, it resolved way more detail.
Just interesting results from my first time out. Nothing substantive, but starts to indicate that stopping down is probably more important to focus on than backing off in the zoom range.
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I did the same with my PLM and I was surprised to find that it is as sharp (or very nearly so) at f/6.3 as it is at f/8, but I'm not sure about that. My 55-300 DA-L got so much sharper stopped down to f/8 that I have a hard time believing the PLM is sharp wide open.
This bird is small and far away. I wonder if the difference would be easier to spot on a closer subject. I'll have to perform more experiments also.
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I was combing through photos and found a couple more. These were taken back-to-back so they may even be the same focus point, +/- any variation from body movement. Again I was far away.
Which is sharpest depends on where you look, IMO. First is f/8, 1/350s, ISO 280. Second is f/6.3, 1/350s, ISO 140. Both 300mm
Maybe mine really is sharp wide open. It's hard to tell on a live subject though. I should do this with a tripod and a detailed, stationary subject.
If mine is indeed as sharp wide open as it is at f/8, either I got a good copy or I got a bad copy and mine is equally blurry at both apertures! 🤣
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I know people think wildlife and action with this lens but I think it’s real strength is landscape you can isolate subjects, frame parts of a vista without needing to ever crop and pick out interesting details with this extended focal range in a very light package.
Couple of cityscape examples below, 1st image at 300mm 2nd at 190mm. Will be going away next weekend and this lens will be coming with me.
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Quote from JBP on July 14, 2022, 4:46 pmI was combing through photos and found a couple more. These were taken back-to-back so they may even be the same focus point, +/- any variation from body movement. Again I was far away.
Which is sharpest depends on where you look, IMO. First is f/8, 1/350s, ISO 280. Second is f/6.3, 1/350s, ISO 140.
Maybe mine really is sharp wide open. It's hard to tell on a live subject though. I should do this with a tripod and a detailed, stationary subject.
If mine is indeed as sharp wide open as it is at f/8, either I got a good copy or I got a bad copy and mine is equally blurry at both apertures!
I think the first example you showed cropped into the bird showed a noticeably difference between the two. At least something you can appreciate with birds because you're often cropping in. Not a huge difference, but better at f8. I need to try f11 now and see how that goes.
The rhino pic is a good example because when you're not super tight, the difference is hard to tell. So I think that goes along with the fact that the difference is low. Which is good. If you have the light, stop down, if you don't, don't worry about it. I remember with the two older 55-300's I tried you absolutely needed to stop down. So this seems like an improvement from that.
Quote from James Warner on July 14, 2022, 10:15 pmQuote from JBP on July 14, 2022, 4:46 pmI was combing through photos and found a couple more. These were taken back-to-back so they may even be the same focus point, +/- any variation from body movement. Again I was far away.
Which is sharpest depends on where you look, IMO. First is f/8, 1/350s, ISO 280. Second is f/6.3, 1/350s, ISO 140.
Maybe mine really is sharp wide open. It's hard to tell on a live subject though. I should do this with a tripod and a detailed, stationary subject.
If mine is indeed as sharp wide open as it is at f/8, either I got a good copy or I got a bad copy and mine is equally blurry at both apertures!
I think the first example you showed cropped into the bird showed a noticeably difference between the two. At least something you can appreciate with birds because you're often cropping in. Not a huge difference, but better at f8. I need to try f11 now and see how that goes.
The rhino pic is a good example because when you're not super tight, the difference is hard to tell. So I think that goes along with the fact that the difference is low. Which is good. If you have the light, stop down, if you don't, don't worry about it. I remember with the two older 55-300's I tried you absolutely needed to stop down. So this seems like an improvement from that.
That sounds right to me. I thought the f/8 bird looked a bit better maybe but wasn't sure if it was in my head. It's not as good a shot as yours and is super duper cropped. I took some more test shots today and sometimes (maybe just one time?) I thought I could spot a difference, other times not, on the back of the camera. Should be easier to tell once I get them on the PC later. I agree, it's absolutely an improvement over the old 55-300's. It was mush wide open...which actually could be a little fun depending on the shot but definitely not for wildlife lol
I forgot to mention the rhino pics are at 300mm. I'll edit that post
Quote from kcphotogeek on July 14, 2022, 6:17 pmI know people think wildlife and action with this lens but I think it’s real strength is landscape you can isolate subjects, frame parts of a vista without needing to ever crop and pick out interesting details with this extended focal range in a very light package.
Couple of cityscape examples below, 1st image at 300mm 2nd at 190mm. Will be going away next weekend and this lens will be coming with me.
I agree, it's really good for that. It's good on the opposite end, too, for close up work. It focuses much closer than the previous 55-300's (or at least closer than my DA-L). I find myself using it for that really often. I think it has great bokeh and at 300mm with the close focus distance it can blur out the background nicely. That and the quiet focus are my favorite features of the lens over its predecessors.
I took some more shots comparing f/6.3 and f/8 yesterday but they're inconclusive. Some f/8 seemed sharper, others f/6.3 even seemed sharper so I did not do a good job of it (I forgot to bring along the tripod). I just want to add some more data, not expecting it to show anything different than the first post by James. It seems like for every lens I have, stopping down is always a good bet to increase sharpness.
I think stopping down probably helps get birds in flight in focus, also, so if you have the light it's definitely worth doing, IMO. Even with the PLM the older Pentax bodies need all the help they can get to track targets (again, IMO). I'm not sure if the PLM has increased my subject tracking keeper rate at all, honestly, but the fast and quiet initial focus is nice.
Here's a photo showing off the PLM bokeh a bit. I don't know if it's technically great or not, just that I like the way it looks. 😁
IMGP1168 by JBP_Mobusaki, on Flickr
