This isn't all that far short of as big as you can go without having to get into panorama stitching

... or getting further away, of course

Most kind, but credit should really go to MattMatic, who passed the technique to me.

Your latest version is certainly contrastier, but at the expense of additional noise. I can't help feeling that it would look better smaller. (Resampling, bicubic, sharper), which would mean you wouldn't need to be so aggressive with the sharpening.

When you use every available pixel like this, it's really pushing the limits of the lens/sensor combination. Better IMHO to pick a smaller final image, which looks sharper even though it isn't.

I took this, for instance, back in August, with only a 400mm lens. It looks a lot better than the 100% crop (ie before I reduced it in size). I've overdone this one a bit, since the noise is just starting to appear. But you can get away with a bit less when it's smaller, and end up still with quite a pleasing image.




If you want to go large, there's no alternative (with a sensible price tag, at least) to going to a proper telescope. Look forward to seeing the results when you do..

You're welcome. I was quite surprised myself that it came up so well.

No sharpening technique can put in detail that wasn't there already. I've noticed if I attempt to sharpen pictures of my own that are out of focus, all I achieve is noise.

Given that, it occurs to me that the problem with the lens, if there is one, isn't so much a lack of sharpness (ie resolution), but a lack of contrast.

By the way, I've taken the liberty of doing a bit of resizing and editing to the OP's photograph.

The first is just after the resize, and the second is after adding a duplicate layer in overlay mode, running a high-pass filter on it (thanks Matt, for the idea some time ago), applying USM to the post-filter layer, flattening the layers and adding a little more USM to the result.

It's still not Astronomy text book standard, but worth persevering with on another day, I think.

Not all lenses' infinity setting is at the end of the focus ring's travel. It often goes a bit further. So focusing at infinity is often no different from focusing at any other distance in practical terms.

What I haven't got my head round is whether the very narrow range over which the focus confirmation indicator is lit is really relevant - whether in reality the circle of confusion is going to be acceptably small anywhere in that range.

If it is, then it's not the focusing. But if it's not that then I don't know why I still get the variation in sharpness I find. I think I've eliminated the atmospherics, movement and light pollution as a source of variation.

I wonder if it's just that the mirror lens, although very light and compact for its focal length, is just not quite good enough, wide open as it has to be, to achieve the sort of sharpness hoped for.

I've had several goes at taking pictures of the moon. One of the things I've noticed is that with a manual focus lens, it's much, much more difficult than you'd think to focus accurately.

Several times, I've taken several shots, all apparently in focus, but only about 1 in 3 is Ok. I do all the rest, of course - tripod, remote, 3s mirror-up mode, short exposures.

It may be that there's another variable that I haven't considered, but I'm tentatively suspecting that getting focus confirmation from the camera is not enough - it has to be right in the middle of the very narrow range over which the camera thinks it's in focus.

John's point about short exposures is a good one though. I'd be inclined to try shorter ones than the 1/45s used for this one. You don't need as much light as you'd think - ISO 400, F8 and 1/45s is several stops more light than I tend to go for (more like ISO 100, F11 and 1/80), although I realise that you can't stop the lens down .

In this one, there was a lot of light about, especially from behind. Natural light only here...




In today's one, it was quite dark in the room, and I picked a smaller aperture and lit him with the built in flash.




But it is the same cat !!

Comments welcome.

Is this the fella?

I was surprised by this relative simplicity when I had that first go at studio work the other week.

Are there any inexpensive studio flash units about, that would do for a home studio? I'm thinking of getting a big piece of black cloth, suspending it from the picture rail, and moving furniture about. To start with, one flash and a reflector would probably do.

Also, how to trigger the studio flash? The built-in's no good, since the pre-flash can't be switched off, and I don't want the bulk of a full-size manual gun. Is there a suitable hotshoe adapter for the trigger cable?

No !!!!!

The wireless triggering that takes place between the built-in flash and a remote wireless slave such as the Sigma EF530 Super, or indeed the Pentax AF360- ad AF540 FGZ is not merely the slave being triggered by the fact that a flash has happened somewhere.

The camera and the flash exchange information using the built-in unit's pre-flash, in order to get the exposure right - the metering takes place during the pre-flash.

You can download the AF540 manual here - it's worth looking through; check out p38 for a description of what happens in wireless mode.

In summary, it says:

- press the shutter button
- flash on camera emits a pre-flash (relays the camera's flash mode)
- external slave emits a pre-flash (camera does metering)
- flash on camera emits another pre-flash (tells the external slave how much to flash)
- external slave emits main flash while shutter's open

So it's not as simple as you'd think. You can do simple wireless triggering with one of those little units that sit on the bottom of any slave flash, and fires the unit when it sees a flash anywhere, but you get none of the exposure control - you have to do it all manually, and you may as well get a cheap slave rather than a properly P-TTL compatible one.

If I were you, I'd bite the bullet, get the camera fixed within warranty.