Very interesting scenario. Our opinion is you were successful in your quest. The near bloom is in focus and the others are not. This is caused by depth of field as set by your aperture. f/5.6 is fairly long for this type shot but it was your choice and you have the results. We need to hear from you as to your degree of satisfaction. Is this what you wanted? If you had wanted less focus on the rear blooms you should have opened up your lens further. You have made a pleasant photograph but your statements indicate you may have wanted more of your chosen effect. Well done for presenting and asking, helps to "get to the next level." Your interest in this opens up wonderful worlds of options in shooting. Keep up the good work.

That is a little misleading. We have to know whether you're changing focal length alone, or whether you are also changing the subject to camera distance to compensate for the different angle of view, therefore keeping the subject approximately the same size in the final image with each focal length.

If the subject size and the f-stop are the same, then the depth of field will be pretty much the same between two different focal lengths. At 10 feet a 100mm lens at f/2.8 gives you a depth of field of 0.33 feet, while at 5 feet with a 50mm at f/2.8 you will also get 0.33 feet. (The subject will be the same size in the frame at 5 feet with a 50mm lens, as it will be at 10 feet with a 100mm lens.)

In the real world in actual practice we do not usually stand in the same place to photograph the same or similar subjects with two different focal lengths. With a shorter focal length lens we move closer in order to frame the subject in the viewfinder. With a shorter focal length, we move in closer and at the same aperture the depth of field will then be the same regardless of focal length.

Yes, a 35mm lens will give you greater apparent depth of field than a 400mm lens when taking a photograph of a person, providing that both photos are taken at the same distance from the subject. If we are photographing a flower, however, we fill the frame with the subject(s). That negates any depth if field advantage to a shorter focal length.

Therefore, for close up and macro photography, longer lenses have two advantages. First, you have greater working distance with a longer lens, and secondly you have a narrower and more realistic looking field of view, which means less distortion of the subject. Fill the frame with someone's face using a wide angle lens and that distortion becomes obvious.

Mike

FYI, I know nothing of the Tamron. In over 50 years of photography, after a few others in my early growth years, I have never purchased any lens brand other than Nikon. Largely because I like durability. I am still using Nikon glass over 50 years old without difficulty. This is not a criticism of any other manufacturers, just my own experience. I can say I’ve owned the Nikon 105 f4 micro since it came out in 74 and it still remains my favorite and functions perfectly. I can’t speak to the new af f2.8 version so have no opinion.

I’d keep working with your 60 for a bit and then see where that leads you. No real need to rush. Persistence pays. Have fun regardless of where you head.