Long Exposures & Stitching w/ Technical Cameras

[colorspace]

Before I buy things and hack them to bits in an effort to address this myself: is there anything out there that would allow me to accurately dictate the length of my long exposures so I can have frame to frame consistency? The closest I've seen is Kapture Groups Long Exposure switch, but that still requires me to 'stop' it.

Anything with a timer?

IQ380; Rod 40 in Copal 0

 

[voidshatter]

Manual stopping of T mode with the Copal 0 shutter is more than adequate, because the difference between 1min59s and 2min1s is so marginal that it is hardly visible in your pictures given the light condition does not change.

The more challenging thing is the change of light condition which would easily make a big difference even you make two successive shots of accurately 2min each, as well as the moving objects e.g. cloud. The use of PTGui and tools in Photoshop would be required. (Example: http://voidshatter.tuchong.com/12548173/)

By the way, you have a CCD back, and it is not recommended to use it for dedicated long exposure shots. Reasons:

a) If you use default settings, you have to wait for a darkframe NR after each long exposure, leaving a big gap between your shots, which is more prone to change of light conditions and moving objects; if you disable darkframe NR by setting camera mode to "Aerial" then you get degraded image quality out of a CCD back.

b) ISO 200 vs ISO 35 (though extended) would lose lots of dynamic range, leaving less room to push shadow in post-processing (even worse than Canon), thus limiting the scene you can shoot. Bracketing may not be practical for the necessity of darkframe NR mentioned above (more prone to change of light conditions and moving objects).

Conclusions in short:

I would rather not stitch long exposures. I would use a CMOS back (e.g. IQ350) to do long exposure. The IQ380 is the "best" digital back you can buy at the moment, but it is not appropriate for dedicated long exposure shots. If I have to own the IQ380 and if I can't afford to own both the IQ380 and the IQ350 at the same time, I would just buy a Nikon D810 to do the long exposure job.

 

[Wayne Fox]

How long of exposures are you needing?

 

[Lars]

I have sometimes adjusted exposure in post using layers, especially if shooting at dusk with several minutes' exposure. Sometimes it works, sometimes the light changes too much in hue so it becomes difficult to match two frames in the stitching.

 

[photographist]

I have sometimes adjusted exposure in post using layers, especially if shooting at dusk with several minutes' exposure. Sometimes it works, sometimes the light changes too much in hue so it becomes difficult to match two frames in the stitching.

Hi Lars ...

Very, very nice work! I am looking a various backs also, and the long exposure question is important to me. I'm looking at the P25+, P45+ and P65+. I'm also considering the Leaf Aptus II-8 What are you shooting with?

Thanks!

Jeffrey

 

[Lars]

Hi Lars ...

Very, very nice work! I am looking a various backs also, and the long exposure question is important to me. I'm looking at the P25+, P45+ and P65+. I'm also considering the Leaf Aptus II-8 What are you shooting with?

Thanks!

Jeffrey

Thanks My high-end work so far has been all large format film, 8x10" down to 6x9/6x17 cm. It's so far not a source of revenue for me so there's no way I can handle the investment or depreciation of MF backs. It's getting closer though. I just got a D810, did some stitched panos but the autostitch software I tried was crap - no good high bit depth workflow. I haven't taken the time to do a manual stitch or write my own software (yet).

 

[GrahamWelland]

Have you tried autopano giga from Kolor? I use this and it is 16bit plus a lot more reliable than things like PS photo merge. It'll also deal with the file sizes needed today too. :thumbup:

 

[Lars]

Have you tried autopano giga from Kolor? I use this and it is 16bit plus a lot more reliable than things like PS photo merge. It'll also deal with the file sizes needed today too. :thumbup:

Nope have not tried it until now. Impressive software so far - thanks for the tip!

 

[gerald.d]

Nope have not tried it until now. Impressive software so far - thanks for the tip!

For relatively small stitches, I'd also definitely recommend trying out PTGui.

<shameless plug>
Close to 3,000 examples of stitches done using both of these programs over on http://www.dubai360.com
</shameless plug>

Kind regards,


Gerald.