Best lens

[igor73]

What lens would be best for Nikon full frame cameras?. I mainly shoot archelogcal artifacts.   I have a D800 and the obvius choise to me was the 50mm f1,4 for small to medium sized objects.  But i am not so happy with the DOF for ths application.  Smallest aperature is f16 on this lens and if you are near the object like 20cm or so the DOF is very shallow even at f16.  I often get images with less then 0.5 image quality for this reason even though i am shooting in studio with strobes on softbox and fast shutter speed 1/250 and ISO 50. 

A 35mm prime would be better perhaps? 

[chadfx]

For very small objects, I have found that it is very difficult to get deep DOF with almost any camera/lens combo. You are starting at a bit of a disadvantage with the full frame D800, which naturally has a shallower DOF compared to smaller sensor cameras. But I even use a micro 4/3 Olympus sometimes, with its 25% smaller sensor, and I still have some issues with objects not always being sharp at the minimum usable aperture. Using different focal lengths can help a bit, but if you use a 35mm lens, your subject will appear smaller in the frame at the same distance...so you move in closer to compensate, and voila...right back at a shallow DOF.

I would recommend looking into focus stacking as a possible solution. I have had good results in PS with it, just make sure that the EXIF camera data is in the resulting images you send into PS.

[igor73]

Yes you are quite right about the focal lengths.  Disapointed that the 50m is limited to f16 though.  But i guess a f22 35mm is only one stop better so you are probaly right. 

I do have 36 mpix at my disposal.  maybe i should move back a bit instead? 

Not keen on another processing step doing focus stacking. 

Sharpening in Photohop?  Would that introduce artifacts for photoscan? 

[chadfx]

A smaller aperture on your lens might not help, as diffraction can start to appear, which will make everything blurrier.

I would say to try moving back, since you do have a lot of pixels to work with. You can use masks other other region controls in PS to help it ignore the extraneous areas of the images. (believe me, I'm keen on the extra step of focus stacking either! it's a very clunky extra step)

[David Cockey]

Moving back so that the object is smaller doesn't really help with depth of field. With the object smaller in the photos the effects of out of focus blur are magnified so the effective depth of field relative to the size of the object remains the same.

I've used focus stacking with good results. No EXIF information in the focus stacked images so I just entered the pixel size and focal length into Camera Calibration (Tools menu).

Sharpening in Photoshop might help but it may also cause loss of information. Try it and let us know how it works.

[igor73]

Hrmm, not easy this    I guess take more pictures and use heavy masking to mask of out of focus areas could work also? 

[chadfx]

Ah yes, good point David...forgot about that factor. I guess there's really no easy way of getting around it, at least until those Lytro light field camera folks can get some higher resolution equipment out there.

I have sent 'not-entirely-sharp' photos into PS, and it will still work with them as best it can. You might get some issues with noisy geometry, etc...but it might be worth a shot....and masking the worst bits out also might not hurt.

[igor73]

Yeah photoscan deal with the pictures  quite well. They are not that bad.  I can also imagine that photoscan quality check also reports lower scores on D800 images compared to lower res cameras because there is so much information in the images?