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Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Sat Oct 01, 2011 6:26 pm
by striking
Back in the film days, if you wanted to produce higher quality images, that is in term of sharpness for larger prints you went up from 35mm to medium format.

Is this the same for the DX/FX systems or is this a whole new kettle of fish? If there is a difference can someone explain it in layman's terms?

Chris O

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Sat Oct 01, 2011 8:32 pm
by Murray Foote
Same and different kettles of fish at the same time. Also, I just posted some relevant comments in another thread.

There are many factors that are common for sharp images: Correct shutter speed, aperture, exposure, camera support, mirror lockup, etc and lens quality.

The FX sensor is larger than DX and other things being equal, will have greater low light sensitivity and greater dynamic range. However, DX and FX cameras can have differing resolutions which is a bit like having finer or coarser film grain. A camera with higher resolution at a given sensor size will in general have smaller sites and less low light capability. However, it's not a simple relationship because the capability of the processing engine can make a big difference too.

The first requirement for print sharpness is to have a well-exposed image. Then all digital images benefit from sharpening, though it's also possible to mangle an image by over-sharpening it. This applies to both digitally-sourced and scanned images. Sharpening is mainly modifying the contrast characteristics, it's not generally feasible to sharpen an inherently unsharp image. Most digital cameras have an anti-aliasing filter over the sensor to prevent moire. Capture sharpening can ameliorate that and is best done by a utility (including Lightroom or Adobe Camera RAW). Creative sharpening is then when you sharpen the image by eye including overall sharpening and sharpening or blurring appropriate parts of the image. You need to be careful not to create haloes or artifacts from the sharpening. Finally, there is output sharpening which is dependant on your intended form or output, web, matte print, glossy print. Once again, this is best done by a utility. Correct sharpening to print on matte paper, for example, may appear oversharpened on screen. You can make sharpening as complex as you like. The simplest way is probably to use Lightroom which has a system of sliders that is easy to understand. Adobe Camera RAW will be the same but Lightroom is better for multiple images.

Generally, it's better to shoot RAW on a digital camera. This gives you much more latitidue for exposure and tonal range though it has no effect on sharpness.

It's highly desirable to profile your monitor with a good colorimeter. Otherwise, the screen will be too bright and the colours and tones will not be accurate and you'll waste a lot of time testing. You're still likely to need to do test prints but it's a lot easier to start from close. If you don't already have one, I'd suggest an Eye One Display Pro.

That also gives you the capability, should you so desire, of soft proofing in Photoshop. This gives you a reasonable accurate view on screen of what your print will look like so you can adjust your file accordingly. Useful but optional.

The size of the file can be a factor in print resolution, especially if you have a heavily cropped image. However, you can upsize digitally-sourced images by up to a factor of about two, though not scanned images. Resolution for printing of the file should be 180dpi or more.

Digital printers don't vary that much in resolution. They vary in maximum print size, whether they can take roll paper, durability (pigment ink printers better), colour gamut and dynamic range. A new top range printer will give great quality but the cheapest printer will stil give very good quality. Printing an image to a higher resolution will make more of a difference on glossy paper.

You can get better quality with a digital print than a darkroom print and though it may seem complex at first, it's actually much easier and quicker to get there. (You can spend a lot of time post-processing in front of a computer, though). And there is the great advantage that you don't have to remember how to dodge and burn each print individually, once your file is right you can print it again and again.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Sat Oct 01, 2011 10:16 pm
by Mr Darcy
At any given point in the development cycle, Yes. But if you compare different generations of camera, then not necessarily. A newer DX system may well outperform an older FX system

For a comparison, compare a Nikon F6 shooting Velvia 50 to a Box Brownie (these were medium format after all) shooting Kodachrome 25.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 12:11 am
by striking
Very informative posts.Thankg guys.

I have read some crap on the net over the past few weeks complicating the whole DX/FX is different to 35mm/Medium format.

Good to know it still basically comes down to the size of the capture media... with a few caveats of course.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 7:54 pm
by striking
Assuming I am interested in going FX in the next 18- 24 months. Would their be any disadvantage in acquiring some nice primes and zooms suitable for the FX sensor?

Will they effect the DX sensor performance in any way?

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 8:35 pm
by Mr Darcy
striking wrote:Assuming I am interested in going FX in the next 18- 24 months. Would their be any disadvantage in acquiring some nice primes and zooms suitable for the FX sensor?

Will they effect the DX sensor performance in any way?

Not at all.
I use FX glass almost exclusively on my DX D200. The only exception is my ultra-wide. For obvious reasons they don't make an FX ultra-wide that is suitable for DX. If anything image quality is better as any problems with the glass are likely to be towards the edges. These are cut off automatically on DX.

One problem you will have though is that you will suddenly want longer lenses when you move to FX. You will want a 300mm to replace your old 200mm to get the same reach.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 8:39 pm
by Murray Foote
In a word, no, sensor performance will be the same. You'll get good performance from the lenses because you're only using the central part. They'll be larger and heavier because they're designed for a larger sensor and you won't have options that are ultrawides on DX.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 8:47 pm
by Steffen
That said, some 35mm lenses do not perform as well with digital sensors as they did on film. This has nothing to do with the DX sensor being smaller, though.

Cheers
Steffen.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 9:15 pm
by striking
I figured as much.. Thanks all, good to know.

Re: Hmm DX/FX is this as simple as medium format/35mm

PostPosted: Mon Oct 03, 2011 9:15 pm
by Murray Foote
... and a caveat to that is that it partly depends on the camera. The D3 and D3s for example are very good at correcting chromatic abberation automatically. There are also correction in Lightroom or Adobe Camera Raw (ACR) that can be automatic for a lens. I don't know how well they work because I haven't had occasion to use them.