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jim_collum3

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Posts posted by jim_collum3

    To M8 or not

    in Leica and Rangefinders

    Posted

    I'm another user who owns both a 1dsMk2 and an M8. If i were interested in the final print being large (> 16x20), i'd be shooting it with the Canon. If i need a focal len > 100mm, i'd shoot it with the Canon. For everything else, I have used the M8 ever since buying it, and haven't picked the Canon up since. Personally, I feel the image quality of the M8 is better than the Canon (on prints up to 16x20). The fact that it's a blast to use is an added benefit. I could care less who makes a camera.. it's a tool.. and despite the issues around the M8, it's an excellent one.

    Digital Back for Large Format (Ebony RV 4x5 U2)

    in Large Format

    Posted

    I've been using a Ebony 4x5 and a Betterlight scanning back in the field for years.. landscape for the most part. Hasn't been many scenes that i haven't been able to capture with it that i couldn't' with film. Gear wise, it isn't much more to carry than an 8x10 field outfit. I've traveled with it and shot extensively in Thailand and Cambodia. I can get most of a day's shooting out of a single Digital Camera Battery (90W), and 2 extended life batteries for the laptop. One of the advantanges is knowing exactly what i got when i leave, and being able to accurately focus to an extent that's not possible with film. I get about 13 stops of useable latitude with it. As far whether film or the back captures more info.. it's pretty meaningless.. both the back and film outresolve 99% of the large format lenses out there.. so it's pretty much a draw.

     

    Granted, there are times when shooting is more difficult.. heavy winds being one of them... although most of the time, those winds would also make film capture difficult. Getting the 'cotton' like long exposure water isn't possible.. but you can still capture it. The cotton appearance of water is just an artifact of time. The scan back will also give an artifact of time, although one that's not usually seen.. and example is at:

     

    http://web1.omniblog.com/_smartsite/modules/image/image_page.php?a=cz1jJmlkPTE4NjQmbT00MDAw

     

    The other time that's not very easily done , is long exposures... if you're shooting > about 5 seconds with film, then you're not going to get the scanning back to capture it. the back has a *very* usable high iso characteristic to it. .much better than any of the single capture devices. It has very large pixels, and does not bayer interpolation. Most of what i shoot in the field is about ISO 2000-2400, and it's pretty much noiseless. (99% of my shooting is done in the morning from about an hour before the sun comes up, and rarely in direct sun). Scan times range from 30 seconds to about 4 minutes. (which means rapidly changing light also presents a big problem.)

     

    If you're doing onsite architectural work, it's also a working solution (again.. with the above caveats.. probably more so than with landscapes. If you go to the Betterlight web site, there are references from some excellent architectual photographers who are using it.

     

    The back isn't everyone's cup of tea. it's a workflow that's a little different than with film (you spend more time making sure the shot comes out right.. i've composed and focussed usng a 8x loupe, only to have to refocus with the scanning software. the added time doesn't bother me much... if i was in a hurry, i'd be using something other than LF to begin with. Also, the type of light that i prefer is also conducive.. pretty much overcast.. so changing light conditions rarely enter into it.

     

    If you're ever in the San Francisco Bay area (Santa Cruz specifically), and would like to go out and shoot, let me know via email

     

    Jim Collum

    BetterLight ScanBacks and Dynamic Range

    in Large Format

    Posted

    I own both the 1ds Mk II and a Betterlight 6K scanning back. There is a difference in the dynamic range between the two.. similar to the difference in shooting transparency vs color negative. Without bracketing (i don't think i've been in a situation where i would need to with the Betterlight), i can get 13 stops of latitude. There is also a difference in pixel 'quality' between the two cameras. Viewed at 100%, there is a trace of digital artifacts (actually something that can be seen with most digital images). The Betterlight image doesn't display these, and there is a sense of added detail past the 100% crop. This is due to the difference in capture methods... the Canon being a Bayer interpolated sensor, and the Betterlight capturing true RGB information for each pixel.

     

    jim

    Will Digital match Large Format?

    in Large Format

    Posted

    already does. i shoot regularly with a Betterlight scanning back.. all field work.. landscapes and such. scan time is anywhere from 30 seconds to about 3 min.

     

    It produces more detailed prints up to 40x50" than 4x5 provia/velvia chrome and has about 12-14 stops of latitude. without the laptop, the unit is smaller and lighter than the film holders i used to carry. I get a ebony field, the betterlight setup, laptop, battery, 5 lenses, loupe, all in a small f64 backpack.

     

    battery lasts an about 10 hours of pretty solid shooting. advantage is i know what i've shot before leaving the site, and i know everything that needs to be in focus, is in focus.

     

    if you shoot a lot of long exposure/ flowing water type shots, then this isn't for you.

     

    (btw.. 42Mp is a bit high for 6x7. i shoot dual stitched canon 1dsmk2 images, giving me about 37-38Mp, and the results end up better than 6x7 chrome.. i use a howtek 4500 drum scanner to scan both 6x7 and 4x5)

     

    jim

    4x5 Betterlight blog from Cambodia (Angkor Wat) and Thailand

    in Large Format

    Posted

    there's color fringing. i'll get a crop and post it to the blog (wait a couple hours though.. i'm not currently at my image computer.)

     

    there are 3 ccd arrays, each with a color filter over it (rgb, 6000 pixels in length). for each exposure period (scan time.. say 1/8th of a sec for the longest), the pixels capture the data, then move over one pixel. if the object has moved in that period of time, then the color information for that pixel isn't recorded (since it's not there anymore).

     

    look later on today for a blog entry

     

    thanks!

     

    jim

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