[DeadJohn]

Mathematically, a 300/2.8 is great for astrophotography because it has a large aperture and fast ratio at the same time. The OP said wide angle with landscape elements, though.

Samyang/Rokinon 24/1.4, 20/1.8, or 14/2.8. Or 16/2.0 if you don't need full frame. Pick the focal length you prefer for the foreground. On an APS-C sensor my default pick would be 16/2.0.

[Zambuka]

Thank you one and all. I’m overwhelmed with the number of responses and with the detailed info. At this time I feel one of the Robinon lens will fit my needs and budget. I look forward to trying it out on her upcoming vacation and report back with any successful images. Again, thanks to all.

[gifthorse]

I'm assuming that you want to shoot the Milky Way. My preference is in the 24-35mm range. You get more of the Milky Way in the frame. Likewise for meteor showers. The meteors aren't as large (in the image) but you're covering more sky, increasing the chances that you'll actually catch a meteor. Back in the day, fast and/or wide lenses were the way to go for night sky/landscape but you have the OGPS. I have fast lenses and I have wide lenses. My favorite is the Vivitar 28mm f2 'close focusing' lens. Fast, relatively wide, and sharp. For wider shots I use the Pentax smc PENTAX-DA 18-55mm F3.5-5.6 AL WR. and the OGPS.

You'll have close to 8 hours of darkness for your adventure, why not try all of your lenses and decide which, if any, really suits your needs.

[interested_observer]

Morning All, I just logged in and saw that I had 2 more likes - and was wondering where they came from - and the link took me here. A post 3 years old, and the information is still good. However, I thought that I would add a bit more to bring it up to date.

A friend of mine - we go milky way shooting together as often as possible, shoots with a K70 using my Sigma 18-35/f1.8. I'm pretty astonished with his results. The acceleration chip in the K70 essentially pulls up the dynamic range to match my K1 - and he gets excellent results. Here is his InstaGram page with a wide range of shots - Login ? Instagram [Note, he likes natural processing - so the milky way is not going to be blown out.] So, for a crop sensor body, you will be hard pressed to match or exceed the results of the Sigma 18-35/f1.8 If you go wider, you loose aperture area (as explained in my prior posts above), thus loose light. If you go longer to get a larger aperture area (to gain additional light), you loose field of view and will need to stitch. Also, on a crop sensor - if you choose to stitch, the 18-35 has really no vignetting, so the panos comes out with excellent results,

Earlier this year, we were talking and he wanted to get a K1mkII - but the question was, what lens. Thus the quest - we looked at everything that had a Pentax K mount. Yes, that does present some limitations - but there are enough of the best recommended lenses available in the K mount that you can make a selection.

With a full frame sensor, the lens selection available (and I will say across any camera brand), you will find problems with everything, regardless. You wind up making a selection on minimizing the problems that you find being the worst. The problems are....

• Vignetting - The really fast lenses f1.4, vignette a lot. In order to get around the problem, you either have to stop down at least one stop - and probably two (which has the advantage of sharpening up the details), or shoot wide open and use post processing utilities to remove or reduce the vignetting.

• Coma - Again the really fast lenses usually suffer from some degree of coma - some more than others. You really need to read the reviews.

• Build Defects - DeCentering - This comment is aimed squarely at Rokinon. Their lenses (especially the 24mm) are notorious for being de-centered.

So, for a full frame sensor - the Sigma 35/f1.4 is probably the best available (and you just deal with the vignetting).

My friend took an acquisition strategy of buying used - from Lens Rentals. They carry K1mkII and will test the bodies (since they only have about 5 of them in stock), essentially cherry pick for the white dot problem. They will also cherry pick the best Sigma 35/f1.4 lens - align and calibrate it on their optical bench, before shipping it to you. So, for slightly less that full retail price - he picked up a body (used/rented once) along with a lens - used/rented once - that were each the best they had available. So far the combination has preformed stellar - and he is very happy.

Let me touch on post-processing software here also.

• DXO Raw Prime - denoises and also removes vignetting from raw files, This works great, as it removes the white dots that some K1 sensors have.

• Camera One - Probably the best raw processor that also removes the K1 white dots and reduces the vignetting. My problem is that overall I get better results with LR, even though C1 has the better raw processor and just removes all traces of the white dots - but it runs $300+.

• Raw Tharepee - Removes the K1 white dots (under denoise impact noise) and does vignetting also.

• LightRoom / PhotoShop - Does a poor job on the K1 white dots and does remove a lot of the vignetting - but most of the time not everything.

• PTGui - is a stitching utility. You can process in LR and then export TIFF files to PTGui for stitching. Check off Exposure Blending which will do some additional vignetting on each of the frames so that you will not get the window pane effect across your pano.

My work flow is to import the K1 DNG files into LR, use DXO Raw Prime to process the K1 DNG files into DXO DNG files in a subdirectory, then use LR to touch things up, export to PTGui, stitch and then use PS to composite sky and foreground together.