Posts: WJShaheen | Ugly Hedgehog

TheDman wrote:

Analysis paralysis is what we do around here! Hundreds of threads spent debating demosaicing or the merits of the Scheimpflug principle, zero time learning to create a good image. You wonder if painters are all sitting in a forum somewhere debating whether horse hair, pig hair or nylon is the best fiber for a fan brush.

I'm certainly aware of "analysis paralysis", because it can take you down a rat-hole and you can get lost and not return.
But, if you can return and get back on a progressive path, and when used to explore new tools and techniques it can be a path to continuous improvement.

Yes, I for one spend a lot of time selecting and composing my subjects for the images I want to capture. Just as you do.
But, again, as long as you do not stay stuck in the rat-hole, the benefits in the long run are worth it, if you want to grow. And we should not be dismissive of those who wish to improve their skills.

Here is a gallery of my progression over the past many years: http://www.pbase.com/wjshaheen/astro_images_by_subject
(Not monetized.)

Thanks for looking.

Mar 1, 2018 09:03:12 #

Photo examples: The top image taken with the D750 (as you can tell from its wider FOV) and the 2nd was from a Nikon D5300. (It's more red since I had the IR filter removed.)

Now, it's been asked why would you want to crop? Well, this object, the Rosette Nebula, is relatively large. So, it would be better captured with the D750.

But, most objects I photograph, such as galaxy M51, are much smaller and I end up cropping. So, that's why I went with the D7500 (at least for now).

Of course, Sony has just come out with the A7III for a not unreasonable price.

Thanks for looking.

William in Gold Canyon, AZ

(Download)

Mar 1, 2018 08:47:00 #

Jim Bob wrote:

I sure do appreciate your patience and time. I think I get it now.

Thank you, Jim. I've been struggling with how to demonstrate this "phenomenon" and your questions have helped me frame it in my thinking.

Attaching screenprints of a tool used to calculate per-pixel field of view (Shown as Image Scale, which equates to resolution) as well as Field of View, in arc-minutes.

I'll look for actual photo examples.

(Download)

Mar 1, 2018 08:28:22 #

Jim Bob wrote:

Understood. I thank you for further elucidation. Although I must confess that if, as you suggest, the D750 has a "denser" image due to larger pixels, it is not clear how it loses the level of resolution you attribute to it when cropped to DX size.

To clarify, the "denser" image is due to a larger chip (not larger pixels) and hence a larger photo area, which will contain more pixels.
So, when you print or view the D750 image on a monitor the field becomes more crowded with more pixels. But, the per pixel field of view is larger.

Of course, the ideal would be to have the D850. with its 4.34 um pixel size (pitch).

Another way to look at it is if, say, you want a head-shot of a bird, with the same field of view, then when you crop to the head, you will lose resolution.

I can upload an example comparison if that will help.

Mar 1, 2018 06:51:59 #

Wireless remote for a Nikon D7100

I have used qDslrDashboard from a laptop, tablet and a phone - and it works great. Where it comes in handy is to show photos on your tablet just after being captured.

Another option if you just want remote triggering and an intervalometer is a Vello Shutterboss II. Very simple and instead of needing a laptop, tablet or phone, you have just a small handheld trigger. There's a newer version III available but I found the II to be very adequate. Both are running a $20 discount at the moment.

Yet another option is a Camranger. But, it may be a bit pricey, depending on what you want to do.

Feb 28, 2018 23:47:16 #

Jim Bob wrote:

So you chose the D7500 because you lost resolution by cropping the D750?

Yes. When cropping to the same region of interest, the D750 image, with its larger pixels, displayed less resolution than the smaller pixels of the D7500.

Feb 28, 2018 10:14:38 #

Jim Bob wrote:

Why would you crop FX to DX size and, according to you, lose resolution in the process?

I'm not saying you would want to. I'm saying to compare the same area as far as resolution. Otherwise, on a monitor or printout, the image with more pixels is somewhat deceiving.

Feb 28, 2018 09:17:52 #

maren wrote:

I am trying to put everything together in my head ... (show quote)

Rather than being the distance between pixels, pixel pitch is the *size* of the pixels. Chip size determines the overall field-of-view. But, resolution is determined by pixel size.
Even though the full-frame Nikon D750 has larger pixels (5.96uM) than the DX format D7500 (4.22uM), when displayed on a monitor or printed, the larger number of pixels provie a "denser" image. If you crop the D750 image to the size of a DX, then it will have lower resolution.

I do mostly astrophotography and so my primary concern is for what's called "image scale", the field-of-view per pixel at a given focal length.

I had a D750 for a couple weeks but returned it for the D7500 because the detail was noticeably less with the D750.

William

Feb 28, 2018 09:01:02 #

16 bit versus 8 bit, again

camerapapi wrote:

Won't it be a perfect world if we could shoot RAW and have our images printed in RAW with a wide color space?

I've been playing with a few photo editing packages, such as Skylum's Luminar 2018 (as just one example).

As part of the process of exporting to a tiff, among other formats, it gives you the option of specifying color space, either sRGB, Adobe RGB or ProPhoto RGB, as well as bit depth. And, of course, it supports direct printing (File/Print).

William

Feb 23, 2018 14:13:33 #

Interested in Tamron 18-400mm f/3.5-6.3

Picture Taker wrote:

Yes but the 28-400 is a better lens. Faster focusing.

I'm not in the market for a lens. I was simply responding to someone inquiring about the Tamron 18-400.

Bill

Feb 23, 2018 14:00:18 #

Interested in Tamron 18-400mm f/3.5-6.3

photodoc16 wrote:

Bill,
Tell me about the 10 - 22. Sharp? (Center and corners), any lens artifacts?, IS?, any comparison to 10 - 24?
Thanks,
Photodoc16

Hi - I was referring to the Tamron 18-400mm.

Bill

Feb 23, 2018 12:51:13 #

Interested in Tamron 18-400mm f/3.5-6.3

pmorin wrote:

I have one of those lenses. It has nice, sharp optics till you get to about 350 on the zoom. Then it gets a little soft. I get a lot of visible shake at max zoom when hand held, but on a tripod it is awesome. As to carrying it around all day, no problem, the weight is easily managed. For the price, the Tamron is well worth having in your bag.

I agree completely. I was going to use it for last summer's eclipse but when I scrutinized the images, it was a tad soft at above 350mm.

But, up to that point, it was very good.

Bill

Feb 21, 2018 09:58:55 #

Which Nikon?

Fotomacher wrote:

I glad to see that you’re still using the venerabl... (show quote)

According to Ken Rockwell: "There is a focus motor in the D7500, so it works with every AF lens made since 1986.".
http://www.kenrockwell.com/nikon/d7500.htm

I love mine.

Feb 21, 2018 09:48:11 #

Which Nikon?

LWW wrote:

Next time you are about to get ran over I’ll remember to not warn you.

I guess we're not allowed to suggest alternatives.

Jan 24, 2018 06:00:45 #

Why is Arthur Morris, wildlife photographer, switching from Canon to Nikon?

Photographer Jim wrote:

Sponsorship deal?
He just wanted to try something different?
He got tired of being corrected for spelling Canon with two n's?

Did you mean to say 3 N's? (It's been annoying me too for some time. "Cannon" And I was in the artillery!)