quincy

Ok, so when you close the aperture while keeping ISO and shutter speed the same, the live view image in your viewfinder should get darker. You can use that information (or the live histogram) to adapt shutter speed or ISO yourself. (Or you let the camera do the job with one of the auto-settings)

If you turn the aperture ring on the lens (when it is attached to the adapter & camera), does the aperture change size?

FD lenses don't transfer aperture information to the camera. The aperture coupling in the FD bayonet was completely manual. If you look at the back of your lens, there is a lever that runs on a circular track. This lever, if moved all the way to the other side, stops your lens down until it reaches the value you set at the aperture ring. This means you need an adapter with a built in mechanical coupler. The simplest ones just have a pin which moves the lever all the way down while you attach the lens to the adapter, and then you can simply adjust the aperture by turning the aperture ring. More fancy ones have an additional ring on the adapter, to simulate the camera stopping down the lens. I have one of those: https://www.metabones.com/products/details/MB_SPFD-X-BM2 You can see the (movable) pin inside the adapter, at the bottom. If your adapter does not have a pin / ring etc., your lens can't stop down. However, even if it does, your camera does not know the aperture setting. Good thing is, the camera does the metering (for exposure) without knowing the aperture setting, by just simply evaluating the live feed off the sensor, and can adjust ISO / shutter speed accordingly.

With Canon FD lenses, two things will not work automatically anymore: focus and aperture setting. Everything else on your camera still works in auto-mode, if you wish so. Especially automatic ISO as well as automatic shutter speed. If your viewfinder is set to "preview exposure and white balance", then what you see is what you get. If you want your camera to evaluate and set your exposure for you, just dial in the aperture you want to have on your lens, and let the camera do the rest (auto-ISO, auto-shutterspeed). You can even chose one of those (e.g. the shutterspeed) yourself, and let the camera set the right exposure via the other one (ISO in this example). If you want to use the camera fully manual (set aperture, shutter speed and ISO yourself), then you can either use the EV meter or the histogram in your viewfinder, or the viewfinder image itself to set the exposure as you want. Just a small hint: use the aperture to define your depth of field, use the shutterspeed to freeze motion (or to allow movement, if you wish), and then use your ISO to compensate for the correct brightness of your image. And have fun!

Depending on the distance between camera and subject, your lenses might change focal length. This is also called focus breathing. Try both lenses focused at infinity.

that adapter is too short (as written in the description). Try to find a "PK-FX" or "K-mount - FX" adapter. You need a correction of the flange distance from Fuji X-Mount (17,7 mm) to Pentax K-Mount (45,46 mm), so the adapter should be 27,76 mm long.

The old one does, but I'm not sure about the new one that comes with the 200/2.

sell both and get the 27/2.8

As lens&body have the newest firmware installed, I think the rotary encoder telling your lens at what focal lenght it is, is either broken or unattached to the mainboard, hence not communicating. If you stop the aperture down yourself to f/8 or something, while at 55 mm, this will probably show as 18 mm f/8. Anyway, your lens needs to be serviced.

if you take a picture at 55 mm, what focal length does the lens report to the camera (what does the exif data say) ?

thanks, that did it

I've added the neewer and lensbaby lenses and removed Meyer Optik Görlitz completely due to the Net SE bankruptcy. I'll add them again if they find a way to deliver what has already been paid and was promised to their (kickstarter) customers and stay alive as a company. The Samyang 85 will follow when it is released. By the way, something is wrong with the upload function. My (new) lens chart needs ~ 228 kB, but i get an error message that i'm not allowed to upload more than 512 kB.

1. My 27/2.8 seems to be sharp at any aperture and any focus distance. However, the X100F focuses closer (10 cm vs 34 cm), and that's the range where softness will probably creep in. On the other side, while this close, you should stop the lens down anyway. 2. No, but close. 23 blurs more, but is obviously wider, so in the end the images might be comparable. For Portraits, out of those two, I'd chose the 27 to have more distance to the subject. For a Headshot of the same magnification, at 60 cm distance to subject with the 27/2.8 and 50 cm distance to subject with the 23/2.0, you'll have ~ 5 cm DOF with the 27 and ~ 3.5 cm DOF with the 23. 3. 27/2.8 is very sharp, but has no "magic dust". That "magic" comes from optical imperfections in the corners of both the 35 and 18 (and probably the 23/2 on the X100F). By the way, I think the X100F might be bulkier than the X-E3 with the 27.

Thanks Patrick, that's nice to hear! however... I can't edit the OP anymore since we got the new forum software?

If you are shooting big animals and you know what you do, the 55-200 might be the perfect lens for you if you don't want to buy the 100-400, which is also much heavier. My 55-200 is almost as sharp as my 80 macro, and definitely sharper than my 100-400. I like the oof-rendering, you can use it wide open at the long end with no drawbacks, it is small and lightweight, so what's not to like about it. On the wide end, however, i think you need to buy both. The 16 is really bad for astro, but nearly perfect for everything else you want. The close focusing capability is great for environmental flower shots. The 12 is absolutely great for astro, (and not bad in all other disciplines), but it is so wide, it will distort your image as soon as the horizon is not in the center of your frame. If you have specific questions, I think i might have all the lenses you are considering.