Equipment & Techniques > Cameras, Lenses and Shooting gear

Gigapixel Lens A7r

<< < (4/4)

David Mills:
Any thoughts on tilt/shift lenses with regard to multi-row panos?

Bart_van_der_Wolf:

--- Quote from: BAPP on August 11, 2015, 06:49:44 am ---Any thoughts on tilt/shift lenses with regard to multi-row panos?
--- End quote ---

Hi,

If the Depth of Field for a given lens, at a given aperture (F-number), is too shallow to cover everything from foreground to background with adequate sharpness, then a lens with Tilt capability may help. This is in particular the case with longer focal lengths, and buy/close foregrounds. But it also depends on how the scene is exactly laid-out (best for focus is roughly in a flattish plane or wedge of optimal focus), and if everything should really be equally sharp, although the latter is usually the case for Gigapixel projects.

Focusing at the hyperfocal distance, or a bit closer, is common procedure with Gigapixel projects. DoF will be from half the hyperfocal distance to infinity. The area in front of that will be visibly slightly less focused, but not in a total blur, the transition is gradual.

For the A7R, the hyperfocal distances for a few common focal lengths could be assumed (with a CoC=1.5x sensel pitch) to be:
35mm, at f/11, 48 feet
35mm, at f/16, 34 feet
50mm, at f/11, 99 feet
50mm, at f/16, 70 feet
70mm, at f/11, 194 feet
70mm, at f/16, 138 feet
85mm, at f/11, 287 feet
85mm, at f/16, 202 feet

So no big issue for somewhat distant vistas, but more tricky when a closer foreground is also present and needs to be in equally crisp focus. Then focus stacking or tilt lenses may be of help.

The Shift capability is perhaps less important for what you are planning, but it allows to have a certain control over how perspective is rendered. However, you already have that with a decent pano stitching application like PTGUI, and shifted images need additional (offset-)settings for a successful stitch. Photoshop often fails at those (maybe recent versions are a bit better?), but memory management of large pano stich projects is not what Photoshop is very good at anyway.

Cheers,
Bart

David Mills:
With regard to the process, I have done many single row stitched HDR panos with pretty good results (see attached). And even though they print fairly large, they are not as large as I need, consequently I’m pushing the envelope and redeveloping my technique and workflow. As of this moment my technical solution would be – 3 row HDR (5 brackets) focus-stacked pano (one row foreground, one row mid, and one row background) with appropriate overlap. Gear is my A7r (soon to be A7rII) and Nodal Ninja or Really Right Stuff pano solutions. Now, back to the original question of this thread – lenses? I am considering the following lenses. Please bear in mind that I am considering the following lenses only from the standpoint of “practicing the technique” and once I’m sufficiently practiced at the technique I’ll spend the money necessary for better glass.   

Samyang (or Rokinon) 85mm f/1.4 Aspherical IF Lens
Samyang (or Rokinon) 100mm f/2.8 Macro Lens
Samyang (or Rokinon) 135mm f/2.0 ED UMC Lens

General comments on these lenses for my application are appreciated and I’m particularly interested in what one might feel is most appropriate the 85mm, 100mm, or 135mm, and why?

I understand these lens manufactures are interchangeable, so whether it’s Samyang or Rokino doesn’t really matter.

NancyP:
Yep, Samyang is the parent manufacturer, they sell the lenses under their own name and to wholesalers who use the names Rokinon, Bower, Pro-Optic, and a few others. The question of  focal length depends on your use and how many frames you want to take per pano. The Samyang 135 is apparently sensational, so if you like manual focus, and have $549.00, you can get a lens that has optical quality similar to the big brands costing 2 to 4 times as much. The 85 is meh, it's an older design, but for an experiment, you can't beat $250.00 for a lens. the 100 hasn't gotten reviewed much.

elf:
Search for writings by Harold Merklinger.  He can answer the question of which lens is best for the images you want to create.   It all depends on the amount of detail you desire and the time it takes to get it. 

Navigation

[0] Message Index

[*] Previous page