It's meant to be funny.... Too bad it's basically true!

Original poster has posted several followups saying that they have ordered a T-mount to Sony adapter.

I will be surprised if it works.

The Topcon 300mm f/2.8 came with the Exaxta/Topcon bayonet mount.

Some of those lenses got modified to be used on other camera systems. It was the only 300mm f/2.8 of the time (and another 8 years or so). Maybe that's why this one has a thread mount. But if it does, I would bet on M42/Pentax/Practika screwmount. T-mount thread is possible, but as far as I can tell the lens wasn't ever made that way and it would have been more involved to modify to put a T-mount on it, than to convert to M42.

If you want a wide-range zoom that's full frame capable for an R-series camera, the RF 24-240mm is probably your best bet. Or adapt an EF 28-300mm. I believe the EF lens was discontinued not long ago, so is only available used, but it is a weather resistant "L" series lens. The RF lens is not, but it's also about half the weight.

This sounds like the best way to get into mirrorless while continuing to use Pentax K-mount lenses.

I don't know what Pentax camera the original poster is using. I find no info on a "Pentax K-DII" model.

Therefore I don't know if it's a full frame or an APS-C format camera. This effects how much weight might be saved going to mirrorless.

The Monster LA-KE1 alone costs $439

Some full frame options that can be found used for $400 to $800:
- Sony a7
- Sony a7 II
- Sony a7S
- Sony a7S II

These full frame Sony cameras weigh roughly 13.5 ounces less than a full frame Pentax K-1 Mark II. The adapter needed to use the lenses weighs around 3.5 ounces. So your net weight savings would be about 10 ounces or a little less than 2/3 lb.

Some APS-C options that can be found used for roughly $350 to $800:
- Sony a6000
- Sony a6100
- Sony a6300
- Sony a6500

Similar to what we saw with full frame, these Sony APS-C format cameras weigh approx. 13.5 ounces less than an APS-C Pentax K-2 Mark II. Once again, the adapter adds back some 3.5 ounces... so the net weight savings will be around 10 ounces or 2/3 lb.

Since the same lens(es) would be in use via the adapter, there's no weight savings from them.

For more significant weight reduction, a clean break to mirrorless system of camera and lenses would be needed.

For example, Sony offers a kit with an APS-C a6100 camera, 16-50mm and 55-210mm lenses for close to what any of the above might cost: $1098. The total weight of this kit is about 2 lb. (a6100 is 14 oz., 16-50mm is 4 oz. and the 55-210mm 12 oz.)

There are also other options, such as:
- Canon R10 or R50 with RF-S 18-45mm and RF-S 55-210mm lenses
- Nikon Z50 with 16-50mm and 50-250mm lenses.

Finally, there are also full frame mirrorless that are more affordable. An older model Sony like their a7 II can be bought with kit lens for under $1000. Another example, the Canon R8 with RF 24-50mm kit lens is selling for $1700. While that Canon is much newer and the company has done better than most reducing the size and weight of their lenses with the shift over to mirrorless, compared to what you've already got there's a limit to how much reduction there would be with full frame capable lenses. Besides Canon, Nikon and Sony, there also are Fuji, Panasonic, OM System (formerly Olympus) to consider. Fuji are APS-C (and larger medium format). Panasonic offers both full frame and micro 4/3... all OM are micro 4/3. If interested, do some research online for the weights of camera and lenses.

I often recommend one or another of the Rebel line, too. They're great cameras and ideal for many peoples' uses.

I started my "digital Canon journey" with a 10D way back in 2004 (transitioning from using Canon EOS-3 and Elan 7 film cameras, alongside an Olympus digital P&S that made 1.5MP images). That was a very nice camera, but only 6MP, used the AF system out of the Elan 7 (a basic seven point AF) and was "the first DSLR to cost less than $2000".... it was $1999! Actually closer to $2500 with battery grip and several extra batteries.

Within a couple months of my purchase of the 10D, Canon introduced the Digital Rebel or "300D" in other parts of the world. It was also 6MP, but it was quite a bit less expensive (1st DSLR under $1500, if I recall correctly) AND it was the first model that could use EF-S lenses, the first of which were introduced at the same time. Another problem with the 10D was that it couldn't shoot RAW + JPEG.... it could only shoot RAW or JPEG. At that time we were shooting events and offering on-site printing services... we could take someone's photo and give them a print within a half hour. That required we shoot JPEGs. However, we also wanted RAW files to be able to improve on images in post-processing. The Digital Rebel/300D also didn't offer a RAW+JPEG mode, so I had to wait for subsequent models.

Rebels today can shoot circles around the $7000 pro cameras of 20 years ago! Today's cameras that cost 90% less have a better AF system, faster frame rate, higher resolution, better high ISO and a bunch of useful features that no one had even thought of back when the first Canon 1D-series cameras were rolling off the assembly line.

Photoshop Elements is an excellent post-processing program. It's more than enough for many peoples' uses.

Sorry to rain on your parade, but for all practical purposes the 77D and T7i are identical inside. They both use the Digic 7 processor, same sensor, same AF system, yada, yada, yada. With one small exception, they have the exact same specs... shutter speed range, ISO range, flash sync, etc., etc., etc. In fact, they were even announced the same day: February 15, 2017.

The exception... There is one feature the 77D has that the T7i doesn't. That's its built-in Intervalometer that can be used for time lapse or a programmed bulb exposure.

The biggest difference, I'm sure you're aware, are the display and control layouts. The T7i uses a control layout common to the Rebel series, while the 77D uses a control layout brought over from the 70D and 80D... LCD display on the top shoulder, mode dial moved to the left, AF On button, dial on the back instead of a multi-directional controller and a few other differences.

Why do I know this stuff even though I don't use either camera? Well, there were a lot of questions about what the rather oddly number EOS 77D was, when it was first announced. Turns out that where the T7i superseded the Rebel T6i, the 77D superseded the Rebel T6s. Those prior cameras were the first time that Canon had split the top of the Rebel line that way. Previously there were just T5i, T4i, etc. The T6s was sort of a "super" top-of-the-line Rebel, alongside the more standard top-of-the-line T6i. The 77D and T7i continued that, just with a change to the model naming methodology.

The T6i and T6s also were announced on the same day in February 2015. In other parts of the world, the T6i was known as an EOS 750D (Kiss X8i in Japan) and the T6s was an EOS 760D (Kiss 8000D in Japan).

The T7i is an EOS 800D (Kiss X9i in Japan), while the 77D appears to use the same name in all markets except Japan, where it's a 9000D.

The point though, is that you can pretty much rest assured that 77D and T7i set up exactly the same way would render results indistinguishable from each other.

What we call "mirrorless" is just a shortened version of the real name for the type of camera: "Mirrorless Interchangeable Lens Camera" or "MILC".

Pentax has made the corporate decision to be the one major camera company that DOES NOT make mirrorless. They have fully committed to just making DSLRs, which most other manufacturers are phasing out.

In answer to your question.... Yes, in general it is possible to adapt many modern DSLR lenses to a newer mirrorless camera. This is usually just when it's the same brand... such as Canon DSLR lenses adapted for use on Canon mirrorless cameras, or Nikon F-mount lenses adapted for Nikon Z-mount cameras. Canon and Nikon both produced adapters to allow their faithful DSLR users to more easily transition to their new mirrorless systems. Canon got a lot more creative with their adapters, offering four different types. Canon's most basic adapter is also much less expensive than Nikon's comparable "FTZ II".... $100 for the Canon EF to RF vs $250 for the Nikon! There also are a number of 3rd party manufacturers making adapters for EF lenses on RF cameras. There are none making Nikon F to Z adapters that support AF and aperture control, only adapters for "D" type lenses that have a manual aperture ring.

There are some brand "crossovers" (for lack of a better term) such as Canon EF mount lenses can be used on Sony E-mount cameras via a Sigma MC-11 adapter which allows auto focus and aperture control. In most cases, though, modern autofocus lenses that use electronic aperture control cannot be adapted to another manufacturers cameras.

It's a different story with legacy or vintage manual focus lenses that have a manual aperture control ring... since there is no need for electronic communication between camera and lens, there are literally dozens or hundreds of different possibilities. Old lenses from film SLRs and rangefinders can be fitted onto many modern mirrorless with simple, inexpensive adapters. There are even some of these types of lenses still being made, so it's not just the legacy and vintage gear. It is quite a bit slower to shoot with these types of lenses, though. Not something you'd want for sports or active wildlife, but can do the job for more relaxed types of shooting.

Nice!

JPEGs can only be partially tweaked in Photoshop or Lightroom. They can be sorted, cataloged and displayed just fine in Lightroom. They also can be adjusted somewhat in both, but how much is more limited and the results often are not as good as they could be working from a RAW file.

Wow!

Current BenQ models are different from some of what's been mentioned in earlier responses. Photography-specific models from the BenQ USA website:

24".... SW241

27".... SW270C, SW271C, SW272Q, SW272U

32".... SW321C

An "X" suffix is added when a calibration device is bundled with the monitor. All the bundles I've seen have come with the Calibrite ColorChecker Pro or Plus

All the above are 100% sRGB/99% Adobe RGB, all are 4K (except the 24" model), all are 10-bit (1 billion colors), all are IPS screens and all include a sunshade.

More info about the BenQ monitors for photography is available here: https://www.benq.com/en-us/monitor/photo-editing.html

Eizo are pretty widely recognized as the best... But BenQ are very, very close to being equal and generally cost less.

https://www.bhphotovideo.com/c/compare/BenQ_SW321C+32+16%3A9+4K+HDR+IPS+Photo+and+Video+Editing+Monitor_vs_BenQ_SW270C+Photographer+27+16%3A9+HDR+IPS+Monitor_vs_BenQ_SW321C+32+4K+HDR+IPS+Photo+and+Video+Editing+Monitor+with+ColorChecker+Display+Plus_vs_BenQ_SW270C+Photographer+27+16%3A9+HDR+IPS+Monitor+with+ColorChecker+Display+Pro/BHitems/1534852-REG_1481844-REG_1706639-REG_1706612-REG

Most of these could probably do the job pretty well:

https://www.bhphotovideo.com/c/products/monitors-and-displays/ci/25766/pn/2?filters=fct_a_gaming-monitors_4911%3Acreative-monitor%2Cfct_display-colors_2717%3A1.07-billion%2Cfct_panel-type_4484%3Aips%2Cfct_screen-size_953%3A27in%7C28in%7C31.1in%7C31.5in%7C32in

You know, when I responded previously I didn't realize how enlarged the image of the horse was.

Frankly, shooting at 1/250 with a "do it all" zoom like an 18-200mm set to 200mm, then looking at the image so magnified... IT IS NOT AT ALL SURPRISING that the enlarged portion is slightly soft. In fact, with many cameras there is a "Bayer filter" on the sensor that deliberately blurs the image slightly. This is done to prevent artifacts in images. Images shot with a camera that has a Bayer filter require sharpening after the fact. Especially when you shoot RAW because there is no sharpening applied to the image in the camera. (Shooting JPEGs applies sharpening in-camera, but also can overdo it pretty easily.) It is necessary and best to apply sharpening in post-processing. And it's usually best to apply sharpening as one of your final steps, after most of the other editing and image sizing has been done.

In fact, the sharpened version shown after applying Topaz AI is quite good, considering how ridiculously magnified the image is. It's fine to magnify images a lot when doing fine retouching work... But it's not good when evaluating sharpness and focus accuracy.

Some things that would help...

1. Use a faster shutter speed. 1/250 is very risky when hand holding a 200mm lens on an APS-C camera. That lens has optical image stabilization, but that can only be of partial assistance.

2. It might help with that particular lens to stop down a little more. You used f/8, which isn't wide open but is only 2/3 stop closed down. Most lenses are sharpest at their middle apertures. f/8 probably would be fine at the 18mm end of the zoom... but at 200mm you might want to try f/11 and see if it is sharper.

3. If need be, bump up your ISO to get that faster shutter speed and smaller aperture. You used ISO 250 for that shot. You would have needed ISO 500 to be able to close the aperture one more stop, then would need a little higher ISO like 800 to get to a higher shutter speed.

4. Get closer to your subject to minimize cropping. There's nothing wrong with that image if your subject is a horse in the distance in a field. But if your subject is just the horse, get closer and "fill your viewfinder" with the horse! (Or use a longer telephoto lens... maybe a 400mm or 500mm in this case. But then you'd also need to up your technique even more, possibly need a tripod and a remote release for the sharpest possible image.)

4. Stop evaluating images excessively magnified on your computer monitor. On most monitors, enlarging a 4000 x 6000 pixel image to "100%" is like making a five foot wide print, then viewing it from 18 or 20" away! OF COURSE it looks like crap! If you viewed the Mona Lisa from 18" you'd see Rembrandt's brush strokes instead of the image. Backed off to 50%, 33% or 25%. Imagine how the image will be used and size the view according to that. I bet the image of the horse looks pretty good at 33% (that's what I use with my computer monitor because it's close to "actual print size" of images, the way I size them).

5. There still may be more you can do, such as using a different focus technique (I use "single point" as much as possible and then I only have myself to blame if focus isn't where I wanted it.) If there's a filter on the lens, try some shots without it. If not already doing so, use the lens hood to shade the lens better. Strong side lighting may cause flare that in turn might effect focus.

It looks like the AI is back-focusing. Waaaayyyy back focusing!

I've been in an airplane that FELT like it was flying backward!

Years ago I had the good fortune to get a ride on "D-AQUI", a 1936 Junkers Ju 52 trimotor, beautifully restored and being operated by Lufthansa Airlines.

17 passenger seats, pilot, copilot and one stewardess.

Before engine startup, it was a bit disconcerting to watch the pilot climb out onto the wing and use a yard stick to check the fuel level!

We took off from San Jose Int'l Airport and followed Hwy 87 south into the Santa Cruz Mtns. During our initial climb from the runway, I swear the cars on the freeway were passing us!

https://commons.wikimedia.org/wiki/File:Junkers_Ju52_(Lufthansa_D-AQUI).jpg

Take-off speed 75 mph
Cruise speed 150 mph
Landing speed 50 - 60 mph

I think the radial engines on the trimotor are rated for about 700 hp each. I can't imagine what it might have been like to fly in the first version Ju 52s (1930), which used a single motor rated at about 800 hp!